JP7086372B1 - Cu-W alloy and its manufacturing method, electric discharge machining electrode and its manufacturing method - Google Patents
Cu-W alloy and its manufacturing method, electric discharge machining electrode and its manufacturing method Download PDFInfo
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Abstract
【課題】 現在容易に入手可能な原料粉末を用いても製造可能であって、放電加工用電極として用いた場合に、超硬合金や高速度鋼等の硬い被加工材に対しても、優れた電極消耗率及び加工速度を有するCu-W系合金及びその製造方法を提供する。【解決手段】 平均粒度が10μm以下であり、最大径が20μm以上80μm以下の粒子を含むBaWO4粉末を用いて、合金組織中にBaWO4粒子が分散し、表面をSEM又は光学顕微鏡で観察したときに、合金組織中に存在するBaWO4粒子の最大径が20μmより大きな粒子が、0.1 mm2の面積の中に２個未満であるCu-W系合金の製造方法であって、Cu-W系合金が体積比でCuを20％以上60％以下、BaWO4を0.1％以上５％未満含有し、残部がWであり、BaWO4粉末とW粉末及びCu粉末とを混合し、得られた混合粉末を粉砕し又は粉砕しないで原料粉末を調製する工程と、原料粉末を成形して成形体を形成する工程と、成形体を焼結する工程とを有するCu-W系合金の製造方法。【選択図】 図１PROBLEM TO BE SOLVED: To produce a raw material powder which is easily available at present, and when used as an electrode for electric discharge machining, it is also excellent for a hard workpiece such as a cemented carbide or a high speed steel. Provided are a Cu-W-based alloy having an electrode consumption rate and a processing speed, and a method for producing the same. SOLUTION: When BaWO4 particles containing particles having an average particle size of 10 μm or less and a maximum diameter of 20 μm or more and 80 μm or less are dispersed in an alloy structure and the surface is observed with an SEM or an optical microscope. , A method for producing Cu-W-based alloys in which the maximum diameter of BaWO4 particles present in the alloy structure is less than 20 particles in an area of 0.1 mm2, and the volume of Cu-W-based alloys is It contains 20% or more and 60% or less of Cu, 0.1% or more and less than 5% of BaWO4, and the balance is W. BaWO4 powder is mixed with W powder and Cu powder, and the obtained mixed powder is crushed or A method for producing a Cu-W-based alloy, which comprises a step of preparing raw material powder without crushing, a step of molding raw material powder to form a molded body, and a step of sintering a molded body. [Selection diagram] Fig. 1
Description
本発明は、Cu-W系合金及びその製造方法、及びCu-W系合金を用いて製造された放電加工用電極及びその製造方法に関する。 The present invention relates to a Cu-W alloy and a method for producing the same, and an electrode for electric discharge machining manufactured using the Cu-W alloy and a method for producing the same.
放電加工とは、電極材料と被加工材との間にパルス状のアーク放電を起こし、発生する高熱と衝撃波でお互いを溶融・除去することを繰り返し行うことにより、被加工材の加工を行う方法である。 Electric discharge machining is a method of machining a work material by repeatedly causing a pulsed arc discharge between the electrode material and the work material and melting and removing each other with the generated high heat and shock wave. Is.
放電加工に適した電極材料としては、電極材料自体の消耗が抑えられ、更に加工速度が速い材料が適当だと考えられている。一般的な電極材料としては、炭素が用いられることが多いが、超硬合金や高速度鋼等の硬い材料には、より熱伝導率や電気伝導率が高い銀や銅と融点が高いタングステンとを組み合わせた銀―タングステン系合金や銅―タングステン系合金が用いられている。一般的には高価な銀―タングステンではなく、銅―タングステンが用いられている。 As an electrode material suitable for electric discharge machining, it is considered that a material that suppresses consumption of the electrode material itself and has a high machining speed is suitable. Carbon is often used as a general electrode material, but for hard materials such as superhard alloys and high-speed steel, silver and copper with higher thermal conductivity and electrical conductivity and tungsten with a higher melting point are used. Silver-tungsten alloys and copper-tungsten alloys that combine the above are used. Generally, copper-tungsten is used instead of the expensive silver-tungsten.
特公昭35-8046号公報（特許文献１）は、銅―タングステン合金に仕事関数の低いアルカリ土類金属またはその酸化物（例えばBaO等）を0.5％～10％添加することで、電極自体の仕事関数を低くし、集中放電を抑え、加工速度を高め、電極消耗率を減らしている。 Japanese Patent Publication No. 35-8046 (Patent Document 1) describes the electrode itself by adding 0.5% to 10% of an alkaline earth metal having a low work function or an oxide thereof (for example, BaO) to a copper-tungsten alloy. It lowers the work function, suppresses concentrated discharge, increases the processing speed, and reduces the electrode wear rate.
特許第2620055号（特許文献２）は、BaOが高価で吸水性があることから、BaOの代わりに、比較的安価で吸水性の無いBaWO4（平均粒度１～５μm）を銅―タングステンに0.1～11体積％添加することで、電極消耗率を減らしている。 In Patent No. 2620055 (Patent Document 2), since BaO is expensive and has water absorbency, BaWO 4 (average particle size 1 to 5 μm), which is relatively inexpensive and has no water absorbency, is 0.1 to copper-tungsten instead of BaO. By adding ~ 11% by volume, the electrode consumption rate is reduced.
特許第3763006号（特許文献３）は、銅が５～30％の銅―タングステンに、Pを0.002～0.04％、もしくはPとCo，Ni及びFeの１種類以上とを0.1~0.5％添加することにより、焼結性を向上させている。PがW粒子に対するCuの濡れ性を下げる効果を有することが特徴である。 Patent No. 3763006 (Patent Document 3) adds 0.002 to 0.04% of P or 0.1 to 0.5% of P and one or more of Co, Ni and Fe to copper-tungsten containing 5 to 30% copper. This improves the sinterability. It is characterized by the fact that P has the effect of lowering the wettability of Cu with respect to W particles.
特許第5318401号（特許文献４）は、Cu-W系合金に0.01～5.00質量％のBiまたはBi2O3を添加することにより、電極消耗率は変化させず、被削性、合金強度を向上させている。一部BaWO4の添加もある。 According to Patent No. 5318401 (Patent Document 4), by adding 0.01 to 5.00 mass% of Bi or Bi 2 O 3 to a Cu-W alloy, the electrode wear rate does not change, and the machinability and alloy strength are improved. It is improving. There is also the addition of some BaWO 4 .
特許文献２や特許文献４では、Cu-W系合金に平均粒度１～５μmのBaWO4を0.1～11体積％添加することで、銅－タングステン材料の放電加工性能の一つである電極消耗率を向上させている。現在入手可能な原料を用いて合金を作成した場合、BaWO4の添加量が多くなると、放電加工性能の一つである加工速度が低下する場合があった。加工速度が低下すると、加工時間が延び、工業的に不利であるため、改善が必要であった。 In Patent Document 2 and Patent Document 4, by adding 0.1 to 11% by volume of BaWO 4 having an average particle size of 1 to 5 μm to a Cu-W alloy, the electrode consumption rate, which is one of the electric discharge machining performances of copper-tungsten materials, is achieved. Is improving. When alloys are prepared using currently available raw materials, if the amount of BaWO 4 added is large, the machining speed, which is one of the electric discharge machining performances, may decrease. When the processing speed was lowered, the processing time was extended and it was industrially disadvantageous, so improvement was necessary.
まず、原料粉末を観察した結果、BaWO4の原料の平均粒度は4.1μmであったが、最大径が50μm程度の粗大な針状の粒子が存在した。 First, as a result of observing the raw material powder, the average particle size of the raw material of BaWO 4 was 4.1 μm, but coarse needle-shaped particles having a maximum diameter of about 50 μm were present.
さらに加工速度が低下したCu-W系合金の合金組織を確認した結果、合金組織中に存在するBaWO4が粗大となり、例えば、合金組織を走査型顕微鏡（SEM）や光学顕微鏡で確認した結果、0.1 mm2の面積の中に最大径が20μmより大きな粒子が２個以上存在していた。そこで、BaWO4の粒子の最大径が20μm以下に細かく分散している合金を得るために、BaWO4の添加量を検討する必要があった。 As a result of confirming the alloy structure of the Cu-W alloy whose processing speed was further reduced, BaWO 4 existing in the alloy structure became coarse, and for example, the alloy structure was confirmed by a scanning microscope (SEM) or an optical microscope. There were two or more particles with a maximum diameter of more than 20 μm in the area of 0.1 mm 2 . Therefore, it was necessary to study the amount of BaWO 4 added in order to obtain an alloy in which the maximum diameter of BaWO 4 particles is finely dispersed to 20 μm or less.
従って、本発明の目的は、現在容易に入手可能な原料粉末を用いても製造可能であって、放電加工用電極として用いた場合に、超硬合金や高速度鋼等の硬い被加工材に対しても、優れた電極消耗率及び加工速度を発揮し得るCu-W系合金及びその製造方法を提供することである。 Therefore, an object of the present invention is that it can be manufactured by using a raw material powder that is easily available at present, and when it is used as an electrode for electric discharge machining, it can be used as a hard workpiece such as cemented carbide or high-speed steel. On the other hand, it is an object of the present invention to provide a Cu-W-based alloy capable of exhibiting an excellent electrode consumption rate and processing speed, and a method for producing the same.
本発明の別の目的は、上記のCu-W系合金を用いた、優れた電極消耗率及び加工速度を有する放電加工用電極及びその製造方法を提供することである。 Another object of the present invention is to provide an electric discharge machining electrode having an excellent electrode consumption rate and machining speed, and a method for manufacturing the same, using the above Cu-W alloy.
平均粒度が4.1μm及び最大径が50μmの市販のBaWO4粉末を用い、BaWO4粉末の最適な添加量を検討した結果、BaWO4粉末の添加量が0.1体積％以上５体積％未満の合金であれば、Cu-W系合金中のBaWO4の粒子の最大径が20μmより大きな粒子が、0.1 mm2の面積の中に２個未満であった。一方で、BaWO4が５体積％以上の添加量の合金では、BaWO4粒子が粗大化しており、最大径が20μmより大きなBaWO4粒子が0.1 mm2の面積の中に２個以上存在した。更にこの粗大なBaWO4粒子があることにより放電加工時の加工速度が低下することが分かった。これは、銅やタングステンよりも電気伝導率がかなり低い酸化物であるBaWO4の粒子が粗大に存在するために起こると考えられる。 As a result of investigating the optimum amount of BaWO 4 powder added using commercially available BaWO 4 powder with an average particle size of 4.1 μm and a maximum diameter of 50 μm, the amount of BaWO 4 powder added was 0.1% by volume or more and less than 5% by volume. If so, there were less than two BaWO 4 particles in the Cu-W alloy having a maximum diameter of more than 20 μm in an area of 0.1 mm 2 . On the other hand, in the alloy in which BaWO 4 was added in an amount of 5% by volume or more, the BaWO 4 particles were coarsened, and two or more BaWO 4 particles having a maximum diameter of more than 20 μm were present in the area of 0.1 mm 2 . Furthermore, it was found that the presence of these coarse BaWO 4 particles reduces the machining speed during electric discharge machining. This is thought to occur due to the coarse presence of BaWO 4 particles, which are oxides with significantly lower electrical conductivity than copper and tungsten.
次に平均粒度4.1μm、最大径が50μmの市販のBaWO4をボールミル処理し、BaWO4粒子を最大径で5μm以下となるように予備粉砕した。本予備粉砕粉末を用いて、５体積％BaWO4が添加されたCu-W系合金を作製した結果、合金中のBaWO4の粒子のうち最大径が20μmよりも大きな粒子が0.1 mm2の面積の中に２個未満であり、加工速度も優れた。したがって、BaWO4の最大径が20μm未満であることが最も重要だと考えられる。また、本予備粉砕により、11体積％までのBaWO4を添加しても、合金中のBaWO4の粒子のうち最大径が20μmよりも大きな粒子が0.1 mm2の面積の中に２個未満であり、加工速度も優れた。一方で、市販で安価に入手可能なBaWO4粉末の最大径は50μm程度であり、この粉末をボールミル等で予備粉砕処理して使用するのは、コストが上がり工業的に良くない。 Next, commercially available BaWO 4 having an average particle size of 4.1 μm and a maximum diameter of 50 μm was ball-milled, and BaWO 4 particles were pre-pulverized so that the maximum diameter was 5 μm or less. As a result of producing a Cu-W alloy to which 5% by volume BaWO 4 was added using this pre-crushed powder, the area of BaWO 4 particles in the alloy having a maximum diameter larger than 20 μm was 0.1 mm 2 . The number of particles was less than two, and the processing speed was excellent. Therefore, it is considered most important that the maximum diameter of BaWO 4 is less than 20 μm. In addition, even if BaWO 4 up to 11% by volume is added by this pre-grinding, less than 2 particles of BaWO 4 having a maximum diameter of more than 20 μm in the alloy are in the area of 0.1 mm 2 . Yes, the processing speed was excellent. On the other hand, the maximum diameter of BaWO 4 powder that can be obtained on the market at low cost is about 50 μm, and it is not industrially good to use this powder after pre-grinding it with a ball mill or the like because of high cost.
以上から、放電加工性能に優れた、特に加工速度を低下させないCu-W系合金を得るためには、最大径が20μmより大きなBaWO4粒子を合金組織中に存在しない様にする必要があり、そのためにはBaWO4の添加量が0.1体積％以上５体積％未満であるのが最適であることが分かった。 From the above, in order to obtain a Cu-W alloy with excellent electric discharge machining performance, especially one that does not reduce the machining speed, it is necessary to prevent BaWO 4 particles having a maximum diameter of more than 20 μm from being present in the alloy structure. For that purpose, it was found that the optimum amount of BaWO 4 added was 0.1% by volume or more and less than 5% by volume.
すなわち、本発明の第一の実施態様によるCu-W系合金は、合金組織中にBaWO4粒子が分散したCu-W系合金であって、体積比でCuを20％以上60％以下、BaWO4を0.1％以上５％未満含有し、残部がWであり、表面をSEM又は光学顕微鏡で観察したときに、合金組織中に存在するBaWO4粒子の最大径が20μmより大きな粒子が、0.1 mm2の面積の中に２個未満であることを特徴とする。 That is, the Cu-W alloy according to the first embodiment of the present invention is a Cu-W alloy in which BaWO 4 particles are dispersed in the alloy structure, and the volume ratio of Cu is 20% or more and 60% or less, BaWO. When the surface is observed with SEM or an optical microscope, the maximum diameter of BaWO 4 particles larger than 20 μm is 0.1 mm, which contains 4 in 0.1% or more and less than 5% and the balance is W. It is characterized by having less than two particles in the area of two .
本実施態様のCu-W系合金は、平均粒度が10μm以下であり最大径が20μm以上80μm以下の粒子を含むBaWO4粉末と、W粉末及びCu粉末とを混合し、得られた混合粉末を粉砕し又は粉砕しないで原料粉末を調製し、前記原料粉末を成形して成形体を形成し、前記成形体を焼結してなるのが好ましい。 The Cu-W-based alloy of the present embodiment is obtained by mixing BaWO 4 powder containing particles having an average particle size of 10 μm or less and a maximum diameter of 20 μm or more and 80 μm or less, W powder and Cu powder, and obtaining a mixed powder. It is preferable that the raw material powder is prepared with or without crushing, the raw material powder is molded to form a molded body, and the molded body is sintered.
前記原料粉末は粉末冶金法では、体積比でCu粉末を20％以上60％以下、BaWO4粉末を0.1％以上５％未満含有し、残部がW粉末であるのが好ましい。また体積比でCu粉末の４％以下がNi粉末，Fe粉末及びCo粉末からなる群から選ばれた少なくとも１種で代替されているのが好ましい。また前記原料粉末は溶浸法では、Cu粉末を体積比で5％以上25％以下、BaWO4粉末を0.15％以上17％未満含有し、残部がW粉末であるのが好ましい。また、体積比でCu粉末の6％以下がNi粉末，Fe粉末及びCo粉末からなる群から選ばれた少なくとも１種で代替されているのが好ましい。 In the powder metallurgy method, the raw material powder preferably contains 20% or more and 60% or less of Cu powder, 0.1% or more and less than 5% of BaWO 4 powder, and the balance is W powder. Further, it is preferable that 4% or less of Cu powder in terms of volume ratio is replaced with at least one selected from the group consisting of Ni powder, Fe powder and Co powder. In the infiltration method, the raw material powder preferably contains Cu powder in a volume ratio of 5% or more and 25% or less, BaWO 4 powder in an amount of 0.15% or more and less than 17%, and the balance is W powder. Further, it is preferable that 6% or less of Cu powder by volume is replaced with at least one selected from the group consisting of Ni powder, Fe powder and Co powder.
本発明の第二の実施態様によるCu-W系合金は、合金組織中にBaWO4粒子が分散したCu-W系合金であって、体積比でCuを20％以上60％以下、BaWO4を0.1％以上11％以下含有し、残部がWであり、平均粒度が10μm以下であり最大径が20μm以上80μm以下の粒子を含むBaWO4粉末をBaWO4粒子の最大径が20μm未満となるように予備粉砕し、W粉末，Cu粉末及び予備粉砕されたBaWO4粉末を混合し、得られた混合粉末を粉砕し又は粉砕しないで原料粉末を調製し、前記原料粉末を成形して成形体を形成し、前記成形体を焼結してなり、表面をSEM又は光学顕微鏡で観察したときに、合金組織中に存在するBaWO4粒子の最大径が20μmより大きな粒子が、0.1 mm2の面積の中に２個未満であることを特徴とする。 The Cu-W-based alloy according to the second embodiment of the present invention is a Cu-W-based alloy in which BaWO 4 particles are dispersed in the alloy structure, and Cu is 20% or more and 60% or less in volume ratio, and BaWO 4 is used. BaWO 4 powder containing 0.1% or more and 11% or less, the balance is W, the average particle size is 10 μm or less, and the maximum diameter is 20 μm or more and 80 μm or less so that the maximum diameter of BaWO 4 particles is less than 20 μm. Pre-crushed, W powder, Cu powder and pre-crushed BaWO 4 powder are mixed, the obtained mixed powder is crushed or not crushed to prepare a raw material powder, and the raw material powder is molded to form a molded body. Then, when the molded body is sintered and the surface is observed with an SEM or an optical microscope, the BaWO 4 particles present in the alloy structure have a maximum diameter of more than 20 μm and are found in an area of 0.1 mm 2 . It is characterized by having less than two particles.
前記W粉末の平均粒度が1.0～5.0μｍであり、前記Cu粉末の平均粒度が30～50μmであるのが好ましい。 The average particle size of the W powder is preferably 1.0 to 5.0 μm, and the average particle size of the Cu powder is preferably 30 to 50 μm.
用いるBaWO4粉末は、最大径が20μm以上80μm以下の粒子を５～80体積％含むのが好ましい。 The BaWO 4 powder used preferably contains 5 to 80% by volume of particles having a maximum diameter of 20 μm or more and 80 μm or less.
体積比でCuの４％以下がNi、Fe及びCoからなる群から選ばれた少なくとも１種で代替されているのが好ましい。 It is preferable that 4% or less of Cu by volume is replaced by at least one selected from the group consisting of Ni, Fe and Co.
本発明の一実施態様による放電加工用電極は、上述のCu-W系合金を用いて作製されたことを特徴とする。 The electrode for electric discharge machining according to one embodiment of the present invention is characterized by being manufactured by using the above-mentioned Cu-W alloy.
本発明の第一の実施態様によるCu-W系合金の製造方法は、平均粒度が10μm以下であり最大径が20μm以上80μm以下の粒子を含むBaWO4粉末を用いて、合金組織中にBaWO4粒子が分散し、表面をSEM又は光学顕微鏡で観察したときに、合金組織中に存在するBaWO4粒子の最大径が20μmより大きな粒子が、0.1 mm2の面積の中に２個未満であるCu-W系合金を製造する方法であって、前記Cu-W系合金が体積比でCuを20％以上60％以下、BaWO4を0.1％以上５％未満含有し、残部がWであり、前記BaWO4粉末とW粉末及びCu粉末とを混合し、得られた混合粉末を粉砕し又は粉砕しないで原料粉末を調製する工程と、前記原料粉末を成形して成形体を形成する工程と、前記成形体を焼結する工程とを有することを特徴とする。 The method for producing a Cu-W-based alloy according to the first embodiment of the present invention uses BaWO 4 powder containing particles having an average particle size of 10 μm or less and a maximum diameter of 20 μm or more and 80 μm or less in the alloy structure. When the particles are dispersed and the surface is observed with an SEM or an optical microscope, there are less than two BaWO 4 particles with a maximum diameter of more than 20 μm in the alloy structure in the area of 0.1 mm 2 . A method for producing a -W-based alloy, wherein the Cu-W-based alloy contains Cu in a volume ratio of 20% or more and 60% or less, BaWO 4 in 0.1% or more and less than 5%, and the balance is W. A step of mixing BaWO 4 powder with W powder and Cu powder to prepare a raw material powder by crushing or not crushing the obtained mixed powder, a step of molding the raw material powder to form a molded body, and the above-mentioned step. It is characterized by having a step of sintering a molded body.
本発明の第二の実施態様によるCu-W系合金の製造方法は、平均粒度が10μm以下であり最大径が20μm以上80μm以下の粒子を含むBaWO4粉末を用いて、合金組織中にBaWO4粒子が分散し、表面をSEM又は光学顕微鏡で観察したとき最大径が20μmより大きなBaWO4粒子が、0.1 mm2の面積の中に２個未満であるCu-W系合金を製造する方法であって、前記Cu-W系合金が体積比でCuを20％以上60％以下、BaWO4を0.1％以上11％以下含有し、残部がWであり、前記BaWO4粉末をBaWO4粒子の最大径が20μm未満となるように予備粉砕する工程と、予備粉砕されたBaWO4粉末とW粉末及びCu粉末とを混合し、得られた混合粉末を粉砕し又は粉砕しないで原料粉末を調製する工程と、前記原料粉末を成形して成形体を形成する工程と、前記成形体を焼結する工程とを有することを特徴とする。 The method for producing a Cu-W-based alloy according to the second embodiment of the present invention uses BaWO 4 powder containing particles having an average particle size of 10 μm or less and a maximum diameter of 20 μm or more and 80 μm or less in the alloy structure. A method for producing Cu-W-based alloys in which less than two BaWO 4 particles with a maximum diameter of more than 20 μm are dispersed in an area of 0.1 mm 2 when the particles are dispersed and the surface is observed with an SEM or an optical microscope. The Cu-W alloy contains Cu in a volume ratio of 20% or more and 60% or less, BaWO 4 in 0.1% or more and 11% or less, the balance is W, and the BaWO 4 powder contains the maximum diameter of BaWO 4 particles. A step of pre-grinding so that the particle size is less than 20 μm, and a step of mixing the pre-crushed BaWO 4 powder with W powder and Cu powder, and preparing a raw material powder without crushing or crushing the obtained mixed powder. It is characterized by having a step of molding the raw material powder to form a molded body and a step of sintering the molded body.
前記焼結工程を粉末冶金法又は溶浸法により行うのが好ましい。 It is preferable to perform the sintering step by a powder metallurgy method or a immersion method.
前記原料粉末は粉末冶金法では、体積比でCu粉末を20％以上60％以下、BaWO4粉末を0.1％以上11％以下含有し、残部がW粉末であるのが好ましい。また体積比でCu粉末の４％以下がNi粉末，Fe粉末及びCo粉末からなる群から選ばれた少なくとも１種で代替されているのが好ましい。また溶浸法の場合、BaWO4粉末及びW粉末を含む混合粉末を成形して成形体を形成し、Cuを加熱溶融させて成形体に浸透させた後、焼結する。原料粉末は溶浸法では、Cu粉末を体積比で5％以上25％以下、BaWO4粉末を0.15％以上17％未満含有し、残部がW粉末であるのが好ましい。また、体積比でCu粉末の6％以下がNi粉末，Fe粉末及びCo粉末からなる群から選ばれた少なくとも１種で代替されているのが好ましい。 In the powder metallurgy method, the raw material powder preferably contains 20% or more and 60% or less of Cu powder, 0.1% or more and 11% or less of BaWO 4 powder, and the balance is W powder. Further, it is preferable that 4% or less of Cu powder in terms of volume ratio is replaced with at least one selected from the group consisting of Ni powder, Fe powder and Co powder. In the case of the infiltration method, a mixed powder containing BaWO 4 powder and W powder is molded to form a molded body, Cu is heated and melted to permeate the molded body, and then sintered. In the infiltration method, the raw material powder preferably contains Cu powder in a volume ratio of 5% or more and 25% or less, BaWO 4 powder in an amount of 0.15% or more and less than 17%, and the balance is W powder. Further, it is preferable that 6% or less of Cu powder by volume is replaced with at least one selected from the group consisting of Ni powder, Fe powder and Co powder.
本発明の一実施態様による放電加工用電極の製造方法は、上述の方法で製造されたCu-W系合金を用いて作製することを特徴とする。 The method for manufacturing an electrode for electric discharge machining according to an embodiment of the present invention is characterized by using a Cu-W alloy manufactured by the above method.
本発明によれば、合金組織中において最大径が20μmより大きなBaWO4粒子が0.1 mm2の面積の中に２個未満とすることにより、放電加工用電極として用いた場合に、超硬合金や高速度鋼等の硬い被加工材に対しても、優れた電極消耗率及び加工速度を有するCu-W系合金を得ることができる。かかるCu-W系合金は放電加工用電極の製造に好適に用いることができる。 According to the present invention, the number of BaWO 4 particles having a maximum diameter of more than 20 μm in the alloy structure is less than two in the area of 0.1 mm 2 , so that when used as an electrode for electric discharge machining, cemented carbide or A Cu-W alloy having an excellent electrode consumption rate and machining speed can be obtained even for a hard workpiece such as high-speed steel. Such a Cu-W alloy can be suitably used for manufacturing an electrode for electric discharge machining.
[1] Cu-W系合金
本発明の一実施態様によるCu-W系合金は、合金組織中にBaWO4粒子が分散したCu-W系合金であって、体積比でCuを20％以上60％以下、BaWO4を0.1％以上５％未満含有し、残部がWであり、表面をSEM又は光学顕微鏡で観察したときに、合金組織中に存在するBaWO4粒子の最大径が20μmより大きな粒子が、0.1 mm2の面積の中に２個未満であることを特徴とする。
[1] Cu-W-based alloy The Cu-W-based alloy according to one embodiment of the present invention is a Cu-W-based alloy in which BaWO 4 particles are dispersed in the alloy structure, and Cu is 20% or more by volume ratio 60. % Or less, BaWO 4 is contained in 0.1% or more and less than 5%, the balance is W, and the maximum diameter of BaWO 4 particles present in the alloy structure is larger than 20 μm when the surface is observed with SEM or an optical microscope. However, it is characterized in that there are less than two particles in an area of 0.1 mm 2 .
本発明のCu-W系合金では、複合酸化物であるBaWO4粒子がCu-W合金からなる母材内に分散しており、かつ最大径が20μmより大きな粗大なBaWO4粒子の数を一定の範囲内に抑えることにより、放電加工用電極として使用すると、仕事関数を低くしつつ、高い電気伝導率及び融点を維持することできる。そのため、本発明のCu-W系合金を放電加工用電極として用いたときに、異常放電の発生を抑制するとともに分散放電が促され、もって電極消耗率及び加工速度の両方の放電加工性能を向上させることができる。 In the Cu-W alloy of the present invention, BaWO 4 particles, which are composite oxides, are dispersed in the base metal made of Cu-W alloy, and the number of coarse BaWO 4 particles having a maximum diameter of more than 20 μm is constant. When used as an electrode for electric discharge machining, it is possible to maintain high electric conductivity and melting point while lowering the work function. Therefore, when the Cu-W alloy of the present invention is used as an electrode for electric discharge machining, the occurrence of abnormal discharge is suppressed and distributed discharge is promoted, thereby improving the electric discharge machining performance of both the electrode consumption rate and the machining speed. Can be made to.
合金組織中のBaWO4粒子の大きさの評価は、走査顕微鏡（SEM）又は光学顕微鏡を用いて、500倍から5,000倍の倍率での観察により行う。ここで、BaWO4粒子の「最大径」とは、BaWO4粒子の端と端を結ぶ直線が最大になる長さを意味しており、BaWO4粒子が針状の粒子である場合は、針状の粒子の長軸方向の両端を結ぶ直線の長さである。さらに、任意の4 mm×8 mmの面積における最大径が20μmよりも大きな粒子の数を求め、0.1 mm2の面積における平均値を算出し、0.1 mm2の面積の中の最大径が20μmよりも大きな粒子の数とする。 Evaluation of the size of BaWO 4 particles in the alloy structure is performed by observation using a scanning microscope (SEM) or an optical microscope at a magnification of 500 to 5,000 times. Here, the "maximum diameter" of the BaWO 4 particle means the length at which the straight line connecting the ends of the BaWO 4 particle is maximized, and if the BaWO 4 particle is a needle-shaped particle, the needle. It is the length of a straight line connecting both ends in the long axis direction of the shaped particles. Furthermore, the number of particles with a maximum diameter larger than 20 μm in an area of arbitrary 4 mm × 8 mm is calculated, the average value in an area of 0.1 mm 2 is calculated, and the maximum diameter in an area of 0.1 mm 2 is from 20 μm. Is also the number of large particles.
本発明のCu-W系合金は、体積比で銅（Cu）を20％以上60％以下、BaWO4を0.1％以上５％未満含有し、残部がタングステン（W）である。Cu-W系合金におけるBaWO4の含有量を0.1体積％以上５体積％未満にすることにより、安価に手に入る粗大粒子を含むBaWO4を用いても、合金組織中の最大径が20μmより大きなBaWO4粒子の数を所定の範囲内に抑えることができる。またCu-W系合金におけるCuの含有量が20％未満であると、焼結性が低下し、Cu-W系合金におけるCuの含有量が60％超であると、放電加工性能が低下する。 The Cu-W alloy of the present invention contains 20% or more and 60% or less of copper (Cu), 0.1% or more and less than 5% of BaWO 4 by volume, and the balance is tungsten (W). By reducing the content of BaWO 4 in the Cu-W alloy to 0.1% by volume or more and less than 5% by volume, even if BaWO 4 containing coarse particles that can be obtained at low cost is used, the maximum diameter in the alloy structure is 20 μm or more. The number of large BaWO 4 particles can be kept within a predetermined range. Further, when the Cu content in the Cu-W alloy is less than 20%, the sinterability is deteriorated, and when the Cu content in the Cu-W alloy is more than 60%, the electric discharge machining performance is deteriorated. ..
WとCuの濡れ性を向上させ、焼結性を向上させるために、Cuの一部をNi、Fe及びCoからなる群から選ばれた少なくとも１種に置換しても良い。Ni、Fe及びCoに置換されるCu量は体積比で４％以下であるのが好ましい。Cu量を４％超置換すると、放電加工性能が低下する。 In order to improve the wettability of W and Cu and improve the sinterability, a part of Cu may be replaced with at least one selected from the group consisting of Ni, Fe and Co. The amount of Cu substituted with Ni, Fe and Co is preferably 4% or less by volume. If the amount of Cu is replaced by more than 4%, the electric discharge machining performance will deteriorate.
[2] Cu-W系合金の製造方法
(1) 第一の実施態様
本発明の第一の実施態様によるCu-W系合金の製造方法は、平均粒度が10μm以下であり最大径が20μm以上80μm以下の粒子を含むBaWO4粉末を用いて、合金組織中にBaWO4粒子が分散し、表面をSEM又は光学顕微鏡で観察したとき合金組織中に存在するBaWO4粒子の最大径が20μmより大きな粒子が、0.1 mm2の面積の中に２個未満であるCu-W系合金を製造する方法であって、前記Cu-W系合金が体積比でCuを20％以上60％以下、BaWO4を0.1％以上５％未満含有し、残部がWであり、前記BaWO4粉末とW粉末及びCu粉末とを混合し、得られた混合粉末を粉砕し又は粉砕しないで原料粉末を調製する工程と、前記原料粉末を成形して成形体を形成する工程と、前記成形体を焼結する工程とを有することを特徴とする。
[2] Manufacturing method of Cu-W alloy
(1) First Embodiment The method for producing a Cu-W-based alloy according to the first embodiment of the present invention uses BaWO 4 powder containing particles having an average particle size of 10 μm or less and a maximum diameter of 20 μm or more and 80 μm or less. Then, BaWO 4 particles are dispersed in the alloy structure, and when the surface is observed with SEM or an optical microscope, the particles having a maximum diameter of more than 20 μm in the alloy structure are contained in the area of 0.1 mm 2 . A method for producing less than two Cu-W-based alloys, in which the Cu-W-based alloy contains 20% or more and 60% or less of Cu and 0.1% or more and less than 5% of BaWO 4 in terms of volume ratio, and the balance. Is W, and the step of mixing the BaWO 4 powder with the W powder and the Cu powder to prepare the raw material powder by crushing or not crushing the obtained mixed powder, and molding the raw material powder to form a molded body. It is characterized by having a step of forming and a step of sintering the molded body.
体積比でCuを20％以上60％以下、BaWO4を0.1％以上５％未満含有し、残部がWとなるようにBaWO4粉末、W粉末及びCu粉末を調整する。現在安価に入手可能なBaWO4粉末は、平均粒度は10μm以下であるが、最大径が20μm以上80μm以下の針状のBaWO4粗大粒子が多数存在している。 Adjust BaWO 4 powder, W powder and Cu powder so that Cu is contained in a volume ratio of 20% or more and 60% or less, BaWO 4 is 0.1% or more and less than 5%, and the balance is W. The BaWO 4 powder currently available at low cost has an average particle size of 10 μm or less, but there are many needle-shaped BaWO 4 coarse particles having a maximum diameter of 20 μm or more and 80 μm or less.
そのような粗大なBaWO4粒子が存在していると、焼結後のCu-W系合金に最大径が20μmよりも大きなBaWO4粒子が増大してしまうため、望ましくない。さらにCu-W系合金の合金組織中に最大径が20μm超のBaWO4相が発生する理由は、(1) 原料粉末として使用するBaWO4粉末の中に最大径が20μm超のBaWO4粒子が含まれることに加えて、(2) 最大径が20μｍ以下のBaWO4粒子が液相焼結中の粒成長により最大径が20μｍ超となる場合がある。すなわち、液相焼結時に、最大径の小さいBaWO4粒子の液相への溶解と相対的に最大径が大きい粒子への析出による粒成長が起きる溶解析出現象が生じると考えられる。本発明のCu-W系合金の製造方法によれば、Cu-W系合金におけるBaWO4の含有量を体積比で0.1％以上５％未満にすることにより、BaWO4粗大粒子の溶解により最大径が20μm超のBaWO4粒子が減少するとともに、析出による粒成長によって最大径が20μm超のBaWO4粒子が生成するのを抑え、安価に入手可能なBaWO4を用いても、合金組織中に存在する、最大径が20μmより大きなBaWO4粒子の数を所定の範囲内に抑えることができる。BaWO4粉末の平均粒度は５μm以下であるのが好ましい。また最大径が20μm以上80μm以下のBaWO4粗大粒子がBaWO4粒子全体に対して含まれる量は２～80体積％であるのが好ましく、５～40体積％であるのがより好ましい。 The presence of such coarse BaWO 4 particles is not desirable because the BaWO 4 particles having a maximum diameter of more than 20 μm increase in the sintered Cu-W alloy. Furthermore, the reasons why BaWO 4 phases with a maximum diameter of more than 20 μm are generated in the alloy structure of Cu-W alloys are as follows: (1) BaWO 4 particles with a maximum diameter of more than 20 μm are contained in the BaWO 4 powder used as the raw material powder. In addition to being included, (2) BaWO 4 particles having a maximum diameter of 20 μm or less may have a maximum diameter of more than 20 μm due to grain growth during liquid phase sintering. That is, it is considered that during liquid phase sintering, a dissolution precipitation phenomenon occurs in which grain growth occurs due to dissolution of BaWO 4 particles having a small maximum diameter in the liquid phase and precipitation into particles having a relatively large maximum diameter. According to the method for producing a Cu-W alloy of the present invention, the BaWO 4 content in the Cu-W alloy is set to 0.1% or more and less than 5% by volume, so that the maximum diameter is increased by dissolving the coarse particles of BaWO 4 . However, the number of BaWO 4 particles over 20 μm is reduced, and the formation of BaWO 4 particles with a maximum diameter of over 20 μm due to grain growth due to precipitation is suppressed. The number of BaWO 4 particles having a maximum diameter of more than 20 μm can be suppressed within a predetermined range. The average particle size of BaWO 4 powder is preferably 5 μm or less. The amount of BaWO 4 coarse particles having a maximum diameter of 20 μm or more and 80 μm or less is preferably 2 to 80% by volume, more preferably 5 to 40% by volume, based on the total BaWO 4 particles.
使用するW粉末の粒子径は0.5μm超30μm未満であるのが適当である。W粉末の粒子径が0.5μm以下だと粉末が酸化しやすく扱いにくく、粉末冶金法で製作した場合は焼結体の形状を保ちにくい。またW粉末の粒子径が30μm以上であると、焼結性が低下する。また溶浸法で製作した場合は、W粉末の粒子径がこの範囲を超えるとCu量のコントロールが難しい。W粉末の粒子径は1.0～10μmであるのがより好ましく、1.0～5.0μmであるのがさらに好ましい。 It is appropriate that the particle size of the W powder used is more than 0.5 μm and less than 30 μm. If the particle size of the W powder is 0.5 μm or less, the powder is easily oxidized and difficult to handle, and when manufactured by the powder metallurgy method, it is difficult to maintain the shape of the sintered body. Further, when the particle size of the W powder is 30 μm or more, the sinterability is lowered. In addition, when manufactured by the immersion method, it is difficult to control the amount of Cu if the particle size of the W powder exceeds this range. The particle size of the W powder is more preferably 1.0 to 10 μm, and even more preferably 1.0 to 5.0 μm.
使用するCu粉末の粒子径は0.1μm以上100μm以下が好ましい。Cu粉末の粒子径が0.1μm未満の場合、酸化しやすく扱いにくい。またCu粉末の粒子径が100μm超であると、焼結性が低下する。Cu粉末の粒子径は1.0～80μmであるのがより好ましく、10～70μmであるのがさらに好ましく、30～50μmであるのが特に好ましい。 The particle size of the Cu powder used is preferably 0.1 μm or more and 100 μm or less. When the particle size of Cu powder is less than 0.1 μm, it is easily oxidized and difficult to handle. Further, when the particle size of the Cu powder exceeds 100 μm, the sinterability is deteriorated. The particle size of the Cu powder is more preferably 1.0 to 80 μm, further preferably 10 to 70 μm, and particularly preferably 30 to 50 μm.
BaWO4粉末、W粉末及びCu粉末を混合し、混合粉末を得る。原料粉末の混合は、湿式及び乾式のいずれで行ってもよい。スチールボール等の媒体とともに撹拌すると原料粉末をより均一に混合することができる。湿式の場合は、分散媒にアルコール等を用いるのが好ましく、原料粉末の分散性を高める目的で公知の分散剤を用いてもよい。 BaWO 4 powder, W powder and Cu powder are mixed to obtain a mixed powder. The raw material powder may be mixed by either a wet method or a dry method. The raw material powder can be mixed more uniformly by stirring with a medium such as a steel ball. In the wet case, it is preferable to use alcohol or the like as the dispersion medium, and a known dispersant may be used for the purpose of improving the dispersibility of the raw material powder.
混合粉末を粉砕し又は粉砕しないで原料粉末を調製する。粉砕工程は、混合粉末を微細に粉砕することを目的としておらず、原料粉末粒子の凝集をほぐして各粒子を均一に混合し、さらにCu粉末粒子にひずみを加えることを目的とする。そのため、各粉末が受ける粉砕のエネルギーは比較的弱めであり、W粉末及びCu粉末の平均粒度は、粉砕工程の前後でほとんど変わらなくても良く、粉砕後の平均粒度／粉砕前の平均粒度が80％以上であっても良い。粉砕工程は湿式及び乾式のいずれで行っても良く、回転式ボールミル、アトライタ、振動ボールミル等を用いても良い。 The raw material powder is prepared by grinding or not grinding the mixed powder. The pulverization step is not aimed at finely pulverizing the mixed powder, but is aimed at loosening the agglomeration of the raw material powder particles, uniformly mixing the particles, and further straining the Cu powder particles. Therefore, the crushing energy received by each powder is relatively weak, and the average particle size of the W powder and Cu powder may be almost the same before and after the crushing step, and the average particle size after crushing / the average particle size before crushing is It may be 80% or more. The pulverization step may be performed by either a wet type or a dry type, and a rotary ball mill, an attritor, a vibrating ball mill or the like may be used.
本発明は、W粉末及びCu粉末の少なくとも一方の粉砕後の最大径が20μm超である場合でも好適に用いることができる。その場合、W粉末及びCu粉末の少なくとも一方の、粉砕後の最大径が20μｍ超の粒子の含有量が、原料粉末全体に対して30体積％以上60体積％以下であるのが好ましい。30体積％未満では焼結体でのCuの分布にムラがでる場合があり、60体積％より多いとき成形体強度がやや低く不具合を生じる場合があり、また焼結体に巣孔が発生することがある。 The present invention can be suitably used even when the maximum diameter of at least one of W powder and Cu powder after pulverization is more than 20 μm. In that case, it is preferable that the content of at least one of the W powder and the Cu powder, which has a maximum diameter of more than 20 μm after pulverization, is 30% by volume or more and 60% by volume or less with respect to the entire raw material powder. If it is less than 30% by volume, the distribution of Cu in the sintered body may be uneven, and if it is more than 60% by volume, the strength of the molded body may be slightly low and problems may occur, and cavities are generated in the sintered body. Sometimes.
粉砕工程において、焼結性を向上させるために、Cu粉末粒子にひずみエネルギーを加えることができる。すなわち、主に媒体の衝突による衝撃により、Cu粉末粒子が塑性変形により扁平に変形し、大きなひずみエネルギーを有するCu粉末粒子が多数生成する。またその際、Cu粉末粒子が一部表面粉砕されても良い。粉砕後のCu粉末の最大径が20μm超であっても良い。 In the pulverization step, strain energy can be applied to the Cu powder particles in order to improve the sinterability. That is, the Cu powder particles are deformed flat by plastic deformation mainly due to the impact caused by the collision of the medium, and a large number of Cu powder particles having a large strain energy are generated. At that time, some Cu powder particles may be partially pulverized on the surface. The maximum diameter of the pulverized Cu powder may be more than 20 μm.
BaWO4粉末についても、同様に凝集をほぐして各粒子を均一に混合することを目的としているが、BaWO4は脆性材料であるため、BaWO4粒子が若干粉砕されるが、最大径が20μm以上80μm以下のBaWO4粗大粒子は残存するものと考えられる。本発明の特徴は、上記粗大粒子が残存していても、体積比でCuを20％以上60％以下、BaWO4を0.1％以上５％未満含有し、残部がWとなるように調整することにより、合金組織中の最大径が20μmより大きなBaWO4粒子の数を所定の範囲内に抑えることができる点にある。従って、BaWO4粉末の微粉砕を行わなくても良く、上記の粉砕工程を省略しても良い。また粉砕工程後の分級を行う必要がないため、製造工程を短縮できる。 The purpose of BaWO 4 powder is to loosen the agglomerates and mix the particles uniformly. However, since BaWO 4 is a brittle material, the BaWO 4 particles are slightly crushed, but the maximum diameter is 20 μm or more. It is considered that BaWO 4 coarse particles of 80 μm or less remain. The feature of the present invention is that even if the coarse particles remain, the volume ratio is adjusted so that Cu is contained in an amount of 20% or more and 60% or less, BaWO 4 is contained in an amount of 0.1% or more and less than 5%, and the balance is W. Therefore, the number of BaWO 4 particles having a maximum diameter of more than 20 μm in the alloy structure can be suppressed within a predetermined range. Therefore, it is not necessary to perform fine pulverization of BaWO 4 powder, and the above pulverization step may be omitted. Moreover, since it is not necessary to perform classification after the crushing process, the manufacturing process can be shortened.
WとCuの濡れ性を向上させ、焼結性を向上させるために、Cu粉末の一部をNi粉末，Fe粉末及びCo粉末からなる群から選ばれた少なくとも１種に置換しても良い。Ni粉末，Fe粉末及びCo粉末に置換されるCu粉末の量は４体積％以下であるのが好ましい。Cu粉末の置換量が４体積％超であると、得られるCu-W系合金の放電加工性能が低下する。 In order to improve the wettability of W and Cu and improve the sinterability, a part of the Cu powder may be replaced with at least one selected from the group consisting of Ni powder, Fe powder and Co powder. The amount of Cu powder substituted with Ni powder, Fe powder and Co powder is preferably 4% by volume or less. If the substitution amount of the Cu powder is more than 4% by volume, the electric discharge machining performance of the obtained Cu-W alloy deteriorates.
原料粉末を成形する工程は、特に限定されないが、圧粉成形等の公知の成形方法を用いることができる。また成形体を焼結する工程は、特に限定されないが、粉末冶金法や溶浸法等の公知の合金製造方法を用いることができる。 The step of molding the raw material powder is not particularly limited, but a known molding method such as compaction molding can be used. The step of sintering the molded product is not particularly limited, but a known alloy manufacturing method such as a powder metallurgy method or a soaking method can be used.
(2) 第二の実施態様
本発明の第二の実施態様によるCu-W系合金の製造方法は、平均粒子径が10μm以下であり最大径が20μm以上80μm以下の粒子を含むBaWO4粉末を用いて、合金組織中にBaWO4粒子が分散し、表面をSEM又は光学顕微鏡で観察したとき合金組織中に存在するBaWO4粒子の最大径が20μmより大きな粒子が、0.1 mm2の面積の中に２個未満であるCu-W系合金を製造する方法であって、前記Cu-W系合金が体積比でCuを20％以上60％以下、BaWO4を0.1％以上11％以下含有し、残部がWであり、前記BaWO4粉末をBaWO4粒子の最大径が20μm未満となるように予備粉砕する工程と、予備粉砕されたBaWO4粉末とW粉末及びCu粉末とを混合し、得られた混合粉末を粉砕し又は粉砕しないで原料粉末を調製する工程と、前記原料粉末を成形して成形体を形成する工程と、前記成形体を焼結する工程とを有することを特徴とする。
(2) Second Embodiment In the method for producing a Cu-W-based alloy according to the second embodiment of the present invention, BaWO 4 powder containing particles having an average particle diameter of 10 μm or less and a maximum diameter of 20 μm or more and 80 μm or less is used. Using, BaWO 4 particles are dispersed in the alloy structure, and when the surface is observed with SEM or an optical microscope, the maximum diameter of BaWO 4 particles present in the alloy structure is larger than 20 μm, and the particles are in the area of 0.1 mm 2 . This is a method for producing less than two Cu-W-based alloys, wherein the Cu-W-based alloy contains 20% or more and 60% or less of Cu and 0.1% or more and 11% or less of BaWO 4 in terms of volume ratio. The balance is W, and the step of pre-grinding the BaWO 4 powder so that the maximum diameter of the BaWO 4 particles is less than 20 μm and the pre-grinding BaWO 4 powder mixed with W powder and Cu powder are obtained. It is characterized by having a step of preparing a raw material powder by crushing or not crushing the mixed powder, a step of molding the raw material powder to form a molded body, and a step of sintering the molded body.
本実施態様では、原料粉末のうちBaWO4粉末のみをBaWO4粒子の最大径が20μm未満となるように予備粉砕している。BaWO4粉末のみを予備粉砕することにより、BaWO4粉末におけるBaWO4粒子の最大径を効率良くより確実に20μm未満とすることができる。予備粉砕工程は湿式及び乾式のいずれで行っても良く、回転式ボールミル、アトライタ、振動ボールミル等を用いても良い。 In this embodiment, only the BaWO 4 powder among the raw material powders is pre-ground so that the maximum diameter of the BaWO 4 particles is less than 20 μm. By pre-grinding only the BaWO 4 powder, the maximum diameter of the BaWO 4 particles in the BaWO 4 powder can be efficiently and more reliably reduced to less than 20 μm. The pre-grinding step may be performed by either a wet type or a dry type, and a rotary ball mill, an attritor, a vibrating ball mill or the like may be used.
予備粉砕工程としては、BaWO4粉末を予備粉砕した後に、BaWO4粒子の最大径が20μm未満となるように分級処理を行っても良い。具体的には、BaWO4粒子の最大径が20μm未満程度になるように予備粉砕処理を行った後、目開きが20μm以下の篩を用いて分級しても良い。ここで、予備粉砕処理や分級処理によっても最大径が20μm以上のBaWO4粒子は若干残るため、「BaWO4粒子の最大径が20μm未満」とは、最大径が20μm以上のBaWO4粒子が微量（10体積％以内）含まれている場合も含まれるものとする。 As a pre-grinding step, after pre-grinding the BaWO 4 powder, a classification treatment may be performed so that the maximum diameter of the BaWO 4 particles is less than 20 μm. Specifically, after performing a preliminary pulverization treatment so that the maximum diameter of BaWO 4 particles is less than about 20 μm, the particles may be classified using a sieve having an opening of 20 μm or less. Here, since some BaWO 4 particles having a maximum diameter of 20 μm or more remain even after the preliminary pulverization treatment or the classification treatment, “the maximum diameter of BaWO 4 particles is less than 20 μm” means that a small amount of BaWO 4 particles having a maximum diameter of 20 μm or more remains. (Within 10% by volume) If it is included, it shall be included.
BaWO4添加量が体積比で５～11％のとき、BaWO4添加量が体積比で0.1％以上５％未満の第一の実施態様の場合と比べて、原料粉末中に含まれる最大径が20μm以上のBaWO4大粒子の頻度は高まる。同時に、液相焼結時の最大径の小さいBaWO4小粒子の溶解も発生し、その溶解総量が第一の実施態様よりも増加してCu液相中のBaやO量は増加する。その結果、第一の実施態様よりも溶解析出機構が発生しやすく、第一の実施態様のときは溶解しやすかったであろう最大径が20μm以上のBaWO4粒子は、BaWO4添加量が体積比で５～11％のときでは逆に粒成長しやすくなり、20μｍ超の粒子が発生する頻度が高まる。従って、第二の実施態様では、原料粉末のうちBaWO4粉末を予備粉砕して最大径が20μm以上のBaWO4粒子の頻度を低減させることにより、最大径が20μm以上80μm以下の針状のBaWO4粒子が多数存在している現在安価に入手可能なBaWO4粉末が出発原料に0.1％以上11％以下含まれる場合であっても、Cu-W系合金に含まれる最大径が20μmより大きなBaWO4粒子の数を抑制し、放電加工用電極として用いたときに優れた電極消耗率及び加工速度を有するCu-W系合金を得ることができる。 When the BaWO 4 addition amount is 5 to 11% by volume, the maximum diameter contained in the raw material powder is larger than that in the case of the first embodiment in which the BaWO 4 addition amount is 0.1% or more and less than 5% by volume. The frequency of BaWO 4 large particles larger than 20 μm increases. At the same time, dissolution of BaWO 4 small particles having a small maximum diameter during liquid phase sintering also occurs, the total amount of dissolution increases as compared with the first embodiment, and the amount of Ba and O in the Cu liquid phase increases. As a result, the dissolution and precipitation mechanism is more likely to occur than in the first embodiment, and the BaWO 4 particles having a maximum diameter of 20 μm or more, which would have been easier to dissolve in the first embodiment, have a volume of BaWO 4 addition. When the ratio is 5 to 11%, on the contrary, grain growth is likely to occur, and the frequency of generation of particles having a diameter of more than 20 μm increases. Therefore, in the second embodiment, the BaWO 4 powder among the raw material powders is pre-pulverized to reduce the frequency of BaWO 4 particles having a maximum diameter of 20 μm or more, thereby reducing the frequency of BaWO 4 particles having a maximum diameter of 20 μm or more and 80 μm or less. Even if the starting material contains 0.1% or more and 11% or less of BaWO 4 powder, which is currently available at a low price and has a large number of 4 particles, the maximum diameter of the Cu-W alloy is larger than 20 μm. It is possible to obtain a Cu-W alloy having an excellent electrode consumption rate and processing speed when used as an electrode for discharge processing by suppressing the number of 4 particles.
予備粉砕されたBaWO4粉末をW粉末及びCu粉末と混合して原料粉末を調製する。BaWO4粉末の予備粉砕を行っているので、原料粉末の粉砕工程は省略しても良いが、使用するW粉末及びCu粉末に応じて混合粉末を適宜粉砕して原料粉末としても良い。成形工程及び焼結工程は、第一の実施態様と同様の方法により行うことができる。 Preground BaWO 4 powder is mixed with W powder and Cu powder to prepare raw material powder. Since the BaWO 4 powder is pre-ground, the crushing step of the raw material powder may be omitted, but the mixed powder may be appropriately crushed according to the W powder and Cu powder to be used to obtain the raw material powder. The molding step and the sintering step can be performed by the same method as in the first embodiment.
[3] 放電加工用電極
本発明の放電加工用電極は、上述のCu-W系合金を用いて製造することを特徴とする。Cu-W系合金に含まれる最大径が20μmより大きなBaWO4粒子の数を抑制しているので、超硬合金や高速度鋼等の硬い被加工材に対しても、優れた電極消耗率及び加工速度を有するCu-W系合金を得ることができる。本発明の放電加工用電極は、ワイヤ放電加工用のカットワイヤ電極にも適用できるが、主として型彫り放電加工に用いられる型彫り放電加工用電極として好適に用いることができる。
[3] Electrode for electric discharge machining The electrode for electric discharge machining of the present invention is characterized by being manufactured by using the above-mentioned Cu-W alloy. Since the number of BaWO 4 particles with a maximum diameter of more than 20 μm contained in Cu-W alloy is suppressed, excellent electrode consumption rate and excellent electrode consumption rate even for hard workpieces such as cemented carbide and high speed steel. A Cu-W alloy having a processing speed can be obtained. Although the electrode for electric discharge machining of the present invention can be applied to a cut wire electrode for wire electric discharge machining, it can be suitably used as an electrode for electric discharge machining mainly used for electric discharge machining.
本発明を実施例によりさらに詳細に説明するが、本発明はそれらに限定されるものではない。 The present invention will be described in more detail by way of examples, but the present invention is not limited thereto.
実施例1
原料として、平均粒度が1.5μmのW粉末、平均粒度が45μmのCu粉末、平均粒度が5μmのNi粉末，Co粉末及びFe粉末、平均粒度が4.4μmであり、最大径が50μmの粒子を含むBaWO4粉末を準備した。これらの粉末を合金にした時に表１に示す組成になるように計量した。尚、粉末冶金法で作製した合金は粉末調製組成が合金の組成となるが、発明品20～22、比較品9は溶浸法で製作しており、製造過程でCuが溶浸により追加されることを考慮して粉末計量を行った。計量した粉末は、ボールミルを用いて、IPA中で48時間湿式混合粉砕した。粉砕混合後の粉末は真空乾燥器を用いて、乾燥させた。尚、混合粉砕後のBaWO4粉末は一部20μm以上の粒子が存在した。この粉末を98 Nの荷重でφ20×20 H(mm)の円柱に圧粉成形した後、1300℃から1500℃の焼結温度で粉末冶金法又は溶浸法で焼結し、発明品１～22及び比較品１～９を作製した。表１に示すように、発明品18の原料粉末にはFe粉末が含まれており、発明品19の原料粉末にはCo粉末が含まれている。
Example 1
As raw materials, W powder with an average particle size of 1.5 μm, Cu powder with an average particle size of 45 μm, Ni powder with an average particle size of 5 μm, Co powder and Fe powder, particles with an average particle size of 4.4 μm and a maximum diameter of 50 μm are included. BaWO 4 powder was prepared. When these powders were made into an alloy, they were weighed so as to have the composition shown in Table 1. The alloy prepared by the powder metallurgy method has the powder preparation composition as the alloy composition, but the inventions 20 to 22 and the comparative product 9 are manufactured by the infiltration method, and Cu is added by infiltration in the manufacturing process. The powder was weighed in consideration of the fact. The weighed powder was wet mixed and milled in IPA for 48 hours using a ball mill. The powder after pulverization and mixing was dried using a vacuum dryer. The BaWO 4 powder after mixing and pulverizing had some particles of 20 μm or more. This powder is compacted into a φ20 × 20 H (mm) cylinder with a load of 98 N, and then sintered by powder metallurgy or immersion method at a sintering temperature of 1300 ° C to 1500 ° C. 22 and comparative products 1 to 9 were prepared. As shown in Table 1, the raw material powder of the invention product 18 contains Fe powder, and the raw material powder of the invention product 19 contains Co powder.
発明品１～22及び比較品１～９の相対密度を、完全に緻密な場合の密度に対する作製した試料の体積と質量から求めた密度の比として求めた。また発明品１～22及び比較品１～９の焼結後の円柱をφ10×20 H (mm)に加工した後、放電加工試験を行った。放電加工試験は、被加工材としてNM-50の超硬合金を用い、荒加工条件にて、装置の深さのオフセットで１mm加工するまで実施した。加工時間，電極の消耗量及び被加工材の加工深さを測定し、比較を行うために、被加工材の加工深さを加工時間で割り算した値を加工速度とし、電極の消耗量を被加工材の加工深さで割り算した値を電極消耗率とした。発明品１～22及び比較品１～９の加工速度及び電極消耗率を表２に示す。また発明品１～22及び比較品１～９における最大径が20μmより大きなBaWO4粗大粒子の有無について、走査顕微鏡を用いて、500倍から5,000倍の倍率で、最大径が20μmより大きなBaWO4粗大粒子が0.1 mm2の面積の中に2個未満であるかどうかで評価を行い、２個未満の試料には最大径が20μmより大きなBaWO4粗大粒子が「無」とし、２個以上あった場合は「有」とした。
The relative densities of Inventions 1 to 22 and Comparative Products 1 to 9 were determined as the ratio of the density obtained from the volume and mass of the prepared sample to the density in the case of perfect density. Further, the sintered cylinders of the inventions 1 to 22 and the comparative products 1 to 9 were machined to φ10 × 20 H (mm), and then an electric discharge machining test was performed. The electric discharge machining test was carried out using a cemented carbide of NM-50 as the work material under rough machining conditions until machining was performed by 1 mm at an offset of the depth of the device. In order to measure and compare the processing time, the amount of electrode wear and the processing depth of the workpiece, the value obtained by dividing the processing depth of the material to be processed by the processing time is used as the processing speed, and the amount of electrode consumption is taken as the processing speed. The value divided by the processing depth of the processed material was taken as the electrode consumption rate. Table 2 shows the processing speeds and electrode wear rates of the inventions 1 to 22 and the comparative products 1 to 9. In addition, regarding the presence or absence of BaWO 4 coarse particles having a maximum diameter of more than 20 μm in Inventions 1 to 22 and Comparative Products 1 to 9, BaWO 4 having a maximum diameter of more than 20 μm at a magnification of 500 to 5,000 times using a scanning microscope. Evaluate whether there are less than 2 coarse particles in the area of 0.1 mm 2 , and for samples with less than 2 particles, there are 2 or more BaWO 4 coarse particles with a maximum diameter larger than 20 μm. If so, it was set to "Yes".
発明品１～22はいずれも最大径が20μmより大きなBaWO4粗大粒子が電極表面積0.1mm2当たり2個未満であり、加工速度が1.4 mm/h以上、かつ電極消耗率が0.15μm/mm以下という優れた結果が得られた。比較品１～４はBaWO4が添加されていないため、電極消耗率が高かった。また比較品５～９はBaWO4が５体積％以上添加されているため、合金組織中に最大径が20μmより大きなBaWO4粗大粒子が0.1 mm2の面積の中に２個以上存在しており、加工速度が低下していた。 Inventive products 1 to 22 have less than two BaWO 4 coarse particles having a maximum diameter of more than 20 μm per 0.1 mm 2 electrode surface area, a processing speed of 1.4 mm / h or more, and an electrode wear rate of 0.15 μm / mm or less. The excellent result was obtained. Since BaWO 4 was not added to Comparative Products 1 to 4, the electrode consumption rate was high. In addition, since BaWO 4 is added in 5% by volume or more in Comparative Products 5 to 9, two or more BaWO 4 coarse particles having a maximum diameter of more than 20 μm are present in the area of 0.1 mm 2 in the alloy structure. , The processing speed was slowing down.
また走査型顕微鏡を用いて、倍率2,500倍にて観察した発明品13及び比較品７の合金組織のSEM写真を図1に示す。最も濃い色の部分がCuを表し、最も薄い色の部分がWを表し、中間色の部分がBaWO4を表している。図１に示すように、発明品13ではBaWO4粒子が細かく分散しているが、比較品７では最大径が20μmより大きなBaWO4粗大粒子が２個以上存在していることが分かる。 FIG. 1 shows SEM photographs of the alloy structures of Invention 13 and Comparative Product 7 observed at a magnification of 2,500 using a scanning microscope. The darkest part represents Cu, the lightest color part represents W, and the neutral color part represents BaWO 4 . As shown in FIG. 1, it can be seen that in the invention product 13, the BaWO 4 particles are finely dispersed, but in the comparative product 7, two or more BaWO 4 coarse particles having a maximum diameter of more than 20 μm are present.
実施例２
Wの粒子径の影響を調査するため、原料として、平均粒度が0.5μm，1.0μm，1.5μm，４μm，20μm及び30μmのW粉末、平均粒度が45μmのCu粉末、５μmのNi粉末、及び平均粒度が4.4μm及び最大径が50μmのBaWO4粉末を準備した。これらの粉末を発明品８と同じ組成W-48.58vol%Cu-0.31vol%Ni-1.39vol%BaWO4となるように、表３に示す割合のW比率で計量した。
Example 2
To investigate the effect of W particle size, as raw materials, W powder with average particle size of 0.5 μm, 1.0 μm, 1.5 μm, 4 μm, 20 μm and 30 μm, Cu powder with average particle size of 45 μm, Ni powder with 5 μm, and average. BaWO 4 powder with a particle size of 4.4 μm and a maximum diameter of 50 μm was prepared. These powders were weighed at the W ratio shown in Table 3 so as to have the same composition W-48.58vol% Cu-0.31vol% Ni-1.39vol% BaWO 4 as that of Invention 8.
計量した粉末を用いて、実施例１と同様の方法により粉砕，成形及び焼結を行い、発明品23～29及び比較品10～12を作製した。各発明品及び各比較品の焼結方法は表４に示す方法を用いた。各発明品及び各比較品について、実施例１と同様に、相対密度、加工速度、電極消耗率及び最大径が20μmより大きなBaWO4粗大粒子の有無を求めた。得られた結果を表４に示す。 Using the weighed powder, pulverization, molding and sintering were carried out by the same method as in Example 1 to prepare Inventions 23 to 29 and Comparative Products 10 to 12. As the sintering method of each invention product and each comparative product, the method shown in Table 4 was used. For each invention product and each comparative product, the presence or absence of BaWO 4 coarse particles having a relative density, a processing speed, an electrode wear rate, and a maximum diameter of more than 20 μm was determined in the same manner as in Example 1. The results obtained are shown in Table 4.
放電加工性能によるW粒子径の影響はあまり大きくなかった。また、粗細混粒にしても性能は変わらなかった。一方で、平均粒度が0.5μmのW粒子を用いた場合、比較品10のように粉末冶金法で焼結すると形状が保持されず、比較品11のように溶浸法で焼結すると銅の割合が多くなった。また、比較品12は平均粒度が30μmのW粉末を用いたため焼結性が悪くなり、相対密度が89％と開気孔－閉気孔の境界である93％よりも低く、緻密体が得られなかった。以上のことから、Wの原料粉末は粒子径が0.5μm超30μm未満であるのが適当であることが分かった。 The influence of the W particle size on the electric discharge machining performance was not so large. In addition, the performance did not change even with coarse and fine mixed grains. On the other hand, when W particles with an average particle size of 0.5 μm are used, the shape is not maintained when sintered by the powder metallurgy method as in Comparative Product 10, and copper is sintered by the infiltration method as in Comparative Product 11. The ratio has increased. In addition, since Comparative Product 12 used W powder with an average particle size of 30 μm, the sinterability deteriorated, and the relative density was 89%, which was lower than 93%, which is the boundary between open pores and closed pores, and a dense body could not be obtained. rice field. From the above, it was found that it is appropriate for the raw material powder of W to have a particle size of more than 0.5 μm and less than 30 μm.
また走査型顕微鏡を用いて、倍率5,000倍にて観察した発明品24～28の合金組織のSEM写真を図２に示す。図１と同様に、最も濃い色の部分がCuを表し、最も薄い色の部分がWを表し、中間色の部分がBaWO4を表している。図２に示すように、発明品24～28ではBaWO4粒子が細かく分散しており、最大径が20μmより大きなBaWO4粗大粒子が無いのが分かる。 FIG. 2 shows SEM photographs of the alloy structures of the inventions 24 to 28 observed at a magnification of 5,000 times using a scanning microscope. Similar to FIG. 1, the darkest color portion represents Cu, the lightest color portion represents W, and the neutral color portion represents BaWO 4 . As shown in FIG. 2, it can be seen that the BaWO 4 particles are finely dispersed in the inventions 24 to 28, and there are no BaWO 4 coarse particles having a maximum diameter of more than 20 μm.
実施例３
原料として、平均粒度が1.5μmのW粉末、平均粒度が45μmのCu粉末、平均粒度が５μmのNi粉末、及び平均粒度が4.4μm及び最大径が50μmのBaWO4粉末を準備した。BaWO4粉末はボールミルを用いて最大径が５μm以下程度になるまで細かく湿式粉砕して、目開き5μmの篩で分級し、予備粉砕工程を行った。予備粉砕されたBaWO4粉末を真空乾燥させた後、予備粉砕されたBaWO4粉末とそれ以外の粉末を比較品７と同じ組で発明品30としてW-39.99vol%Cu-0.26vol%Ni-5.00vol%BaWO4、また発明品31としてW-39.99vol%Cu-0.26vol%Ni-11.00vol%BaWO4となるように計量し、計量された原料粉末をボールミルを用いてIPA中で48時間湿式混合粉砕した。
Example 3
As raw materials, W powder having an average particle size of 1.5 μm, Cu powder having an average particle size of 45 μm, Ni powder having an average particle size of 5 μm, and BaWO 4 powder having an average particle size of 4.4 μm and a maximum diameter of 50 μm were prepared. The BaWO 4 powder was finely wet-pulverized using a ball mill until the maximum diameter was about 5 μm or less, classified by a sieve having an opening of 5 μm, and subjected to a preliminary pulverization step. After vacuum-drying the pre-ground BaWO 4 powder, the pre-ground BaWO 4 powder and other powders are combined with the comparative product 7 as Invention 30 and W-39.99vol% Cu-0.26vol% Ni- Weighed to 5.00vol% BaWO 4 and W-39.99vol% Cu-0.26vol% Ni-11.00vol% BaWO 4 as Invention 31, and weighed the raw material powder in IPA for 48 hours using a ball mill. Wet mixed and pulverized.
粉砕混合後の原料粉末を用いて、実施例１と同様の方法により成形及び粉末冶金法による焼結を行い、発明品30及び31を作製した。発明品30及び31について、実施例１と同様に、相対密度、加工速度、電極消耗率及び最大径が20μmより大きなBaWO4粗大粒子の有無を求めた。得られた結果を表５に示す。実施例２と同様に走査型顕微鏡を用いて発明品30のBaWO4粒子の大きさを評価した結果、予備粉砕していないBaWO4粉末を用いた比較品７の場合は最大径が20μmより大きなBaWO4粗大粒子が0.1 mm2の面積の中に3個存在し、加工速度の低下がみられたが、予備粉砕したBaWO4を用いた発明品30及び31の場合、最大径が20μmより大きなBaWO4粗大粒子が無く、加工速度の低下は見られなかった。 Using the raw material powder after pulverization and mixing, molding and sintering by the powder metallurgy method were carried out by the same method as in Example 1 to prepare inventions 30 and 31. For the inventions 30 and 31, the presence or absence of BaWO 4 coarse particles having a relative density, a processing speed, an electrode consumption rate, and a maximum diameter of more than 20 μm was determined in the same manner as in Example 1. The results obtained are shown in Table 5. As a result of evaluating the size of the BaWO 4 particles of the invention 30 using a scanning microscope in the same manner as in Example 2, the maximum diameter of the comparative product 7 using the BaWO 4 powder not pre-ground is larger than 20 μm. Three BaWO 4 coarse particles were present in an area of 0.1 mm 2 , and the processing speed was reduced. However, in the case of inventions 30 and 31 using pre-ground BaWO 4 , the maximum diameter is larger than 20 μm. There were no BaWO 4 coarse particles, and no decrease in processing speed was observed.
Claims (12)
前記Cu-W系合金が体積比でCuを20％以上60％以下、BaWO4を0.1％以上５％未満含有し、残部がWであり、
前記BaWO4粉末とW粉末及びCu粉末とを混合し、得られた混合粉末を粉砕し又は粉砕しないで原料粉末を調製する工程と、
前記原料粉末を成形して成形体を形成する工程と、
前記成形体を焼結する工程とを有することを特徴とするCu-W系合金の製造方法。 Using BaWO 4 powder containing particles with an average particle size of 10 μm or less and a maximum diameter of 20 μm or more and 80 μm or less, the BaWO 4 particles are dispersed in the alloy structure, and when the surface is observed with an SEM or an optical microscope, the alloy is used. A method for producing Cu-W alloys in which less than two BaWO 4 particles present in the structure have a maximum diameter of more than 20 μm in an area of 0.1 mm 2 .
The Cu-W alloy contains 20% or more and 60% or less of Cu by volume, 0.1% or more and less than 5% of BaWO 4 , and the balance is W.
A step of mixing the BaWO 4 powder with W powder and Cu powder, and preparing a raw material powder by crushing or not crushing the obtained mixed powder.
The process of molding the raw material powder to form a molded body and
A method for producing a Cu-W alloy, which comprises a step of sintering the molded product.
前記Cu-W系合金が体積比でCuを20％以上60％以下、BaWO4を0.1％以上11％以下含有し、残部がWであり、
前記BaWO4粉末をBaWO4粒子の最大径が20μm未満となるように予備粉砕する工程と、
予備粉砕されたBaWO4粉末とW粉末及びCu粉末とを混合し、得られた混合粉末を粉砕し又は粉砕しないで原料粉末を調製する工程と、
前記原料粉末を成形して成形体を形成する工程と、
前記成形体を焼結する工程とを有することを特徴とするCu-W系合金の製造方法。 Using BaWO 4 powder containing particles with an average particle size of 10 μm or less and a maximum diameter of 20 μm or more and 80 μm or less, the BaWO 4 particles are dispersed in the alloy structure, and when the surface is observed with an SEM or an optical microscope, the alloy is used. A method for producing Cu-W alloys in which less than two BaWO 4 particles present in the structure have a maximum diameter of more than 20 μm in an area of 0.1 mm 2 .
The Cu-W alloy contains 20% or more and 60% or less of Cu, 0.1% or more and 11% or less of BaWO 4 by volume, and the balance is W.
The step of pre-grinding the BaWO 4 powder so that the maximum diameter of the BaWO 4 particles is less than 20 μm, and
The step of mixing the pre-ground BaWO 4 powder with the W powder and the Cu powder, and preparing the raw material powder without crushing or crushing the obtained mixed powder.
The process of molding the raw material powder to form a molded body and
A method for producing a Cu-W alloy, which comprises a step of sintering the molded product.
体積比でCuを20％以上60％以下、BaWO4を0.1％以上５％未満含有し、残部がWであり、
表面をSEM又は光学顕微鏡で観察したときに、合金組織中に存在するBaWO4粒子の最大径が20μmより大きな粒子が、0.1 mm2の面積の中に２個未満であることを特徴とするCu-W系合金。 A Cu-W alloy in which BaWO 4 particles are dispersed in the alloy structure.
It contains 20% or more and 60% or less of Cu by volume, 0.1% or more and less than 5% of BaWO 4 , and the balance is W.
When the surface is observed with an SEM or an optical microscope, Cu having a maximum diameter of BaWO 4 particles larger than 20 μm in the alloy structure is less than two particles in an area of 0.1 mm 2 . -W-based alloy.
体積比でCuを20％以上60％以下、BaWO4を0.1％以上11％以下含有し、残部がWであり、
平均粒度が10μm以下であり、最大径が20μm以上80μm以下の粒子を含むBaWO4粉末をBaWO4粒子の最大径が20μm未満となるように予備粉砕し、W粉末，Cu粉末及び予備粉砕されたBaWO4粉末を混合し、得られた混合粉末を粉砕し又は粉砕しないで原料粉末を調製し、前記原料粉末を成形して成形体を形成し、前記成形体を焼結してなり、
表面をSEM又は光学顕微鏡で観察したときに、合金組織中に存在するBaWO4粒子の最大径が20μmより大きな粒子が、0.1 mm2の面積の中に２個未満であることを特徴とするCu-W系合金。 A Cu-W alloy in which BaWO 4 particles are dispersed in the alloy structure.
It contains 20% or more and 60% or less of Cu by volume, 0.1% or more and 11% or less of BaWO 4 , and the balance is W.
BaWO 4 powder containing particles with an average particle size of 10 μm or less and a maximum diameter of 20 μm or more and 80 μm or less was pre-ground so that the maximum diameter of BaWO 4 particles was less than 20 μm, and W powder, Cu powder and pre-crushed. BaWO 4 powder is mixed, the obtained mixed powder is crushed or not crushed to prepare a raw material powder, the raw material powder is molded to form a molded body, and the molded body is sintered.
When the surface is observed with an SEM or an optical microscope, Cu having a maximum diameter of BaWO 4 particles larger than 20 μm in the alloy structure is less than two particles in an area of 0.1 mm 2 . -W-based alloy.
An electrode for electric discharge machining, which is manufactured by using the Cu-W alloy according to any one of claims 6 to 8.
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| JPH08127837A (en) * | 1994-11-01 | 1996-05-21 | Fuji Dies Kk | Cu-W alloy |
| JP2006002188A (en) * | 2004-06-15 | 2006-01-05 | Yasushi Watanabe | Copper-based material and manufacturing method therefor |
| JP2013158843A (en) * | 2012-02-01 | 2013-08-19 | Nippon Tungsten Co Ltd | Electrode for electric discharge machining |
| JP2020012196A (en) * | 2018-07-10 | 2020-01-23 | 東邦金属株式会社 | Electrode material for discharge processing or heat sink for semiconductor, and manufacturing method therefor |
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| JPH08127837A (en) * | 1994-11-01 | 1996-05-21 | Fuji Dies Kk | Cu-W alloy |
| JP2006002188A (en) * | 2004-06-15 | 2006-01-05 | Yasushi Watanabe | Copper-based material and manufacturing method therefor |
| JP2013158843A (en) * | 2012-02-01 | 2013-08-19 | Nippon Tungsten Co Ltd | Electrode for electric discharge machining |
| JP2020012196A (en) * | 2018-07-10 | 2020-01-23 | 東邦金属株式会社 | Electrode material for discharge processing or heat sink for semiconductor, and manufacturing method therefor |
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