JP3359750B2 - Method for producing zirconium amorphous alloy rod and zirconium amorphous alloy cast by die - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a zirconium amorphous alloy rod, and more particularly, to a method for producing a zirconium amorphous alloy rod having a large sectional area and a long length. By doing so, the zirconium material can be applied to various industrial parts.
Furthermore, the present invention relates to a zirconium amorphous alloy having a composition suitable for mold molding.

[0002]

2. Description of the Related Art Zirconium alloys are used for dies for artificial fiber spinning, electric filaments, etc. because of their high corrosion resistance, high heat resistance and high strength. In addition, since the neutron absorption cross section is particularly small, the demand for rod materials such as fuel cladding tubes and control rod guide tubes for nuclear reactors is increasing, and Zircaloy 2 (Zr-
1.5Sn-0.12Fe-0.10Cr-0.05Ni) and Zircaloy 4 (Zr
−1.5Sn−0.2Fe−0.10Cr).

[0003] Two of the present applicants are disclosed in Japanese Unexamined Patent Publication No. Hei 3-15844.
In JP-A-6, a Zr-based alloy to which at least one of Ni, Cu, Fe, Co, and Mn and a predetermined amount of Al are added can be made amorphous by a liquid quenching method, a sputtering method, an atomizing method, or the like. , Also hardness, strength, bendability, heat resistance,
It discloses that properties such as corrosion resistance are excellent. Also,
It has also been disclosed that in this composition, the temperature range of the supercooled liquid state is 50K or more, and therefore, plastic workability is improved.

As described above, in the supercooled liquid state, the amorphous Z
Since the viscosity of the r alloy rapidly decreases, an amorphous alloy compact can be easily produced in this temperature range by an appropriate processing method such as closed forging. One of the present applicants worked with other researchers on the outline of the 44th Joint Lecture on Plastic Working, Section 4
45, Zr ₆₅ Al _7.5 Cu having a thickness of several tens μm
A method to make _27.5 into gears for micromachines was announced.

[0005] Further, it is known to add various elements such as Pd, Rh, Ag, and Au as additive elements to a zirconium foil strip for brazing (JP-A-59-11635).
No. 0, JP-A-59-1226739).

Conventionally known single roll method, twin roll method,
Since amorphous alloys that can be produced by a method such as gas atomization are limited to foil strips, flakes, and powders, applications of zirconium amorphous alloys are considerably limited from an industrial viewpoint.

[0007] On the other hand, in recent years, attempts have been made to produce bulky zirconium amorphous alloys (refer to the 113th Annual Meeting of the Japan Institute of Metals, 1993, Item 579 ). In this method, a mother alloy (not described in composition) melted in an arc furnace is cast from a quartz nozzle into a copper mold, and a Zr round bar having a diameter of 5 mm is obtained.

[0008]

However, the rod-shaped zirconium alloy production method disclosed in the above-mentioned lecture summary of the Japan Institute of Metals is a discontinuous batch method, and the rod obtained by this method is a raw material rod for producing a large member. The material is not large enough. If a zirconium amorphous alloy can be continuously manufactured in a rod shape having a cross-sectional dimension of several mm or more, industrial productivity is expected to increase, and its use is expected to greatly expand. That is, while crystalline zirconium alloys are difficult to machine due to their high strength, high hardness, high-temperature activity, etc., zirconium amorphous alloys have relatively good plastic workability, so forging rod-like materials It can be deformed into a part shape or a substantially part shape by plastic working such as extrusion and pressing, and industrial production of practical parts becomes possible.

Regarding the composition of the zirconium amorphous alloy, many attempts have been made to improve the composition of thin materials such as foils and ribbons. No studies have been made from the viewpoint of what composition is suitable for making the zirconium alloy amorphous. That is, (a) the mold casting is cooled from the bottom and both sides of the mold, and the rotating roll cooling is one-way cooling from the roll surface; (b) the mold cooling is the contact time between the molten metal and the mold. The present inventors have paid attention to the fact that the contact time with the roll is short, but the solidification process is easily affected by residual oxygen and the like in the mold cooling method. The above point was not taken into consideration, and it was found that this was not suitable.

[0010]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a zirconium amorphous material employing a dissolving and solidifying means which is essentially different from the conventional liquid quenching method. A manufacturing method for continuously manufacturing alloy bars,
The present inventors have found alloy components suitable for mold molding and completed the present invention.

That is, according to the present invention, a zirconium alloy containing an amorphizing element is placed in a forced cooling mold having a rod-shaped molding cavity having an open upper surface, and high-frequency induction heating is performed.
Arc melting, electron beam, laser or infrared irradiation irradiates the zirconium alloy in a cross section from the upper surface in the molding cavity to the lower surface of the mold cavity to form a melting region, and at least one of a heating heat source and a forced cooling mold is oriented in the direction of the rod. The present invention relates to a method for manufacturing a zirconium amorphous alloy bar, wherein the melting region is moved in the longitudinal direction of the forced cooling mold by relatively moving the molten region.

Further, the zirconium die-cast according to the present invention is provided.
The alloy has a composition represented by the general formula: Zr _100-abc A _a
B _b C _c (where A is one or more elements selected from Ti, Hf, Al, Ga, B is Fe, Co, Ni,
One or more elements selected from Cu, C is P
d, Pt, Au, Ag, and one or more elements selected from the group consisting of a, b, and c, each of which has an atomic ratio of 5 ≦ a ≦ 20, 20 ≦ b ≦ 40, and 0 <c. ≦ 10 and 30 ≦ a + b + c ≦ 70, and have a temperature range of the supercooled liquid region of 100K or more (ΔT = crystallization temperature (Tx) −glass transition temperature (Tg)). is there. Hereinafter, the configuration and preferred embodiments of the present invention will be described.

In the present invention, a mold having a rod-shaped mold cavity having an open upper surface is used for casting a large-section zirconium amorphous alloy having a rod-like shape. Further, the solidification method of the molten metal is such that a solid material is melted in a mold and rapidly solidified at that location. The heating for this melting may be high-frequency induction heating, high-frequency induction heating, arc discharge, electron beam, laser or infrared irradiation, which can perform rapid heating, have a high energy density and can concentrate energy locally. is necessary. As the heating heat source, a laser is preferable.

Further, in the melting, it is necessary to melt the zirconium alloy in the molding cavity from the top surface to the bottom surface so that the cooling effect of the forced cooling mold is directly applied to the molten metal from the bottom surface and both side surfaces. Thereafter, when one or both of the heating heat source and the forced cooling mold are moved, the molten metal is melted in the next adjacent region and the molten metal to which the heat from the heating source is not supplied is immediately quenched. By performing this movement in the length direction of the rod-shaped material, a desired long material can be manufactured. In order to make amorphous by the above method, it is necessary to make zirconium contain an amorphizing element.

According to the above method, the zirconium amorphous alloy rod has a cross-sectional area of 10 mm ² or more and a length of 5 mm.
Those having a size of 0 mm or more can be easily manufactured. Further, those having a cross-sectional area of 100 mm ² or more and a length of 150 mm or more can be manufactured.

In the above method, water, gas (liquefied gas) or the like can be preferably used as a coolant for the forced cooling mold.

The amorphous elements are Ni, Cu, Fe, Cu,
One or more selected from Pd, Pt, Hf, Au, Ag, Ti, Al, and Ga are used. The addition amount of the amorphizing element is 50 atomic% in consideration of the diameter and material properties of the rod.
It is determined appropriately below.

According to the method of the present invention, a zirconium amorphous alloy rod having a volume fraction of an amorphous phase of 50 to 100% can be produced. The volume fraction of the amorphous phase in the bar is 50%
If it is above, the viscosity in the supercooled liquid region is sufficiently reduced, and in connection with this, the bar shows good plastic workability. Further, the particle size of the crystal phase in the amorphous matrix is 100 μm.
If it is below, cracks or the like due to deformation of the crystal phase during plastic working can be prevented, and a sound final product member can be formed. However, since the amorphous forming ability may not be sufficient depending on the composition of the raw material alloy, non-uniform crystal nuclei are generated and grown from the water-cooled mold during solidification, and the crystalline is mixed in the amorphous. To avoid such difficulties, Zr _100-abc A _a B
It is preferred to use a _b C _c alloy.

The characteristics of the zirconium alloy composition suitable for die casting will be described below. Element A is an element that has the effect of expanding the temperature width [ΔT = crystallization temperature (T _x ) −glass transition temperature (T _g )] of the cooling liquid region without lowering the amorphous forming ability of the alloy. When the addition amount of the element A is less than 5 atomic percent or more than 20 atomic percent, the supercooled liquid region becomes smaller than 100 K and the plastic workability is deteriorated. The content is preferably in the range of 10 to 15 atomic percent, and the element A is preferably Al or Ga.

The element B is an element that forms an amorphous phase. When the amount of the element B is less than 20 at.% Or more than 40 at.
The range was 0 to 40 atomic percent. Preferably 25
The element B is preferably Cu, Ni, or Co.

Element C is an element that suppresses crystal nuclei generated and grown in the amorphous material without impairing the ability to form the amorphous material and the expansion of the supercooled liquid region. Further, Pd, Pt, A
Since u and Ag generally have extremely high chemical stability,
This has the effect of preventing other additional elements from reacting with the remaining oxygen to form oxides. Therefore, non-uniform crystal nuclei having oxides as nuclei are suppressed, and the alloy is more likely to become amorphous. Moreover, these elements are excellent in thermal conductivity, and the heat dissipation of the molten alloy is increased and the cooling rate is increased, so that the amorphous forming ability in the casting method of the present invention is enhanced, and a wide area suitable for plastic working. It is considered that a supercooled liquid region can be formed. When the addition amount of the C element is 0 atomic percent, a large amount of crystal nuclei are generated and grown in the amorphous rod, so that cracks due to the crystal phase occur during subsequent plastic working. If it exceeds 10 atomic percent, the ability to form an amorphous phase is reduced.
It is preferably in the range of 5 to 10 atomic percent, and Pd and Pt are preferable as the C element.

Further, it is necessary that the total amount of the additional elements satisfies 30 ≦ a + b + c ≦ 70 in atomic percent. If the total amount is less than 30 atomic percent or more than 70 atomic percent, no amorphous phase is formed.
≦ a + b + c ≦ 70. The total amount is 35 ≦ a + b
The range of + c ≦ 65 is preferable.

Further, the temperature width of the supercooled liquid region (ΔT =
The crystallization temperature (T _x ) -glass transition temperature (T _g ) is 10
When the temperature is 0 K or more, an amorphous alloy bar excellent in plastic workability in a supercooled liquid region can be obtained.

FIG. 1 shows a water-cooled mold 1 and a heating heat source 2 for obtaining a zirconium amorphous alloy bar. The water-cooled mold 1 is desirably made of pure copper having a large heat capacity and good heat conductivity, and has a cavity formed therein for flowing cooling water or the like. In the upper part of the water-cooled mold 1, a cavity 3 whose upper surface is opened for forming a bar is defined. Further, the water-cooled mold 1 or the heating heat source 2 has a structure that can be arbitrarily moved to the left and right so that the melting region, which is the portion 5 where the raw material is melted by heating, can be moved.

An example of a method for manufacturing the alloy bar of the present invention using such an apparatus will be described. In the manufacturing operation, a material alloy 4 having a predetermined composition adjusted in advance in the cavity 3 and having an arbitrary form such as a rod, a pellet, or a powder is arranged, and an appropriate heating heat source 2 is applied from one end of the material alloy.
Is used to melt a part of the raw material alloy 4. Thereafter, by moving the water-cooled mold 1 or the heating heat source 2, the melting portion is moved toward the other end of the raw material alloy, and is sequentially and continuously melted. As the molten part 5 of the raw material alloy moves, the molten metal that does not receive heat loses heat and is cooled by the water-cooled mold 1 to become amorphous. Hereinafter, the present invention will be described with reference to examples.

[0026]

EXAMPLES Materials having the alloy compositions shown in Table 1 (Example 1)
10, Comparative Examples 1 to 5) are shown in Figure 1, the cross-sectional area 120 mm ² using a dissolver molding apparatus with arc heating heat source,
A rod-shaped sample having a length of 280 mm was prepared. For comparison, a material of the same alloy composition was used to form a 5 mm
A button-shaped ingot sample having a height of 5 mm was prepared, and a ribbon-shaped sample having a thickness of 20 μm and a width of 1 mm was prepared by a single roll method. The amorphous phase of each sample was measured by an X-ray diffraction method, and the temperature width (ΔT) of the supercooled liquid region in the ribbon-shaped sample was measured by a differential scanning calorimeter. The plastic workability of the alloy bar of the present invention was evaluated by applying pressure to the bar heated to the supercooled liquid transition temperature obtained from the ribbon-shaped sample, deforming the bar, and evaluating the crack after the deformation. Table 1 shows the results.

[0027]

[Table 1] Sample Shape ΔT _x Deformation Sample No. Alloy composition Continuous button Cracking of ribbon (K) (atomic%) Presence or absence of rod shape Example 1 Zr ₅₅ Al ₅ Cu ₃₂ Ni ₅ Pt ₃ Amorphous Amorphous Amorphous 118 None Example 2 Zr ₆₀ Al ₁₀ Cu ₂₅ Fe ₂ Pt ₃ Amorphous Amorphous Amorphous 110 None Example 3 Zr ₆₀ Al ₁₀ Cu ₂₅ Pt ₄ Au ₁ Amorphous Amorphous Amorphous quality 112 No example _{4 Zr 55 Al 10 Ti 5 Cu} 25 Pt 5 amorphous amorphous amorphous 108 No example _{5 Zr 62 Al 10 Ni 10 Cu} 15 Pt 3 amorphous amorphous amorphous 105 None Example 6 Zr ₆₂ Al ₁₀ Ni ₇ Cu ₁₅ Co ₃ Pt ₃ Amorphous Amorphous Amorphous 120 None Example 7 Zr ₆₀ Al ₅ Cu ₂₂ Pd ₃ Amorphous Amorphous Amorphous 114 None Performed example _{8 Zr 60 Al 10 Ni 10 Cu} 17 Pd 2 Ag 1 amorphous amorphous amorphous 115 No example _{9 Zr 60 Al 10 Ni 10 Cu} 15 Pd 5 amorphous amorphous amorphous 119 free practice example _{10 Zr 50 Al 15 Ni 10 Cu} 15 Co 5 Pd 5 amorphous amorphous amorphous 121 No Comparative example _{1 Zr 80 Al 5 Cu 10 Pd} 5 crystalline crystalline crystalline - Yes Comparative _{2 Zr 65 Al 3 Cu 27 Pt} 5 crystalline crystalline amorphous 68 Yes Comparative Example _{3 Zr 50 Al 25 Cu 20 Pd} 5 crystalline crystalline amorphous 87 Yes Comparative Example 4 Zr ₆₀ Al ₁₀ Cu ₃₀ - crystalline amorphous amorphous amorphous 61 Yes Comparative example _{5 Zr 50 Al 10 Cu 25 Pt} 15 crystalline amorphous amorphous 50 in perforated table shows that the volume ratio is 50% or more.

As shown in Table 1, the rod-shaped samples having the alloy compositions of Examples 1 to 10 were all 50% or more amorphous, but Comparative Examples 1 to 5 had low amorphous forming ability and 50% or more. It became crystalline. In addition, as a result of the deformation test in the supercooled liquid region, in Examples 1 to 10 of the present invention, cracks were not found at the time of deformation, and a sound deformed product was obtained. In Comparative Examples 1 to 5, since the crystal phase in the rod-shaped sample was contained by 50% or more by volume ratio, cracks caused by deformation of the crystal phase were partially observed, and a sound deformed product was not obtained.

In Comparative Examples 1 to 5, Comparative Example 1 was made of Al.
(Component A) and Pd (Component C) are within the scope of the present invention,
u (B component) is less than the lower limit of the present invention. Cu (B component) of Comparative Example 2
Min) and Pt (C component) are within the scope of the present invention, but Al (A component)
Min) is less than the lower limit of the present invention. Cu (B component) of Comparative Example 3 and
Although Pd (C component) is within the scope of the present invention, Al (A component is
Light limit exceeded. Comparative Example 4 contained the C component.
Absent. Al (A component) and Cu (B component) of Comparative Example 5 are within the scope of the present invention.
However, Pt (C component) exceeds the upper limit of the present invention. When the composition of Comparative Examples 1 to 5 was changed to a rod-shaped cross-sectional area of 10 mm ² to prepare a continuous rod-shaped sample by the same method as above, an amorphous material was obtained in an amount of 50% or more.

[0030]

As described above, in the method according to the first to fourth aspects of the present invention, a rod-shaped zirconium amorphous alloy is continuously produced by combining a mold structure, a heating heat source, and a melting process. The large-section rod-shaped material obtained by such a method is used for practical parts, for example, fuel cladding of a nuclear reactor, utilizing the excellent strength, heat resistance, corrosion resistance, etc. inherent in zirconium amorphous alloy. Can be applied to the tube material. Further, since the alloy of the present invention according to claims 5 to 8 has extremely good amorphous forming ability and has a wide supercooled liquid region, materials for various practical parts can be produced by plastic working. Further, by plastically processing the bar-shaped material having the large cross-sectional area according to the eighth aspect, the production cost of parts can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional front view of an apparatus for producing a zirconium amorphous alloy bar.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water-cooled metal mold 2 Heating heat source 3 Cavity 4 Raw material alloy 5 Melting part (area)

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshihiko Yokoyama 1-9-11, Hakutori, Taihaku-ku, Sendai, Miyagi Prefecture (72) Inventor Yoshiyuki Shinohara 1-9-9 Yaesu, Chuo-ku, Tokyo Teikoku Piston Ring Co., Ltd. (72) Inventor Nobuyuki Nishiyama 1-9-9 Yaesu, Chuo-ku, Tokyo Imperial Piston Ring Co., Ltd. (56) References JP-A-2-282450 (JP, A) JP-A-7-188877 (JP) JP-A-60-89531 (JP, A) JP-A-63-11647 (JP, A) JP-A-59-126739 (JP, A) JP-A-55-148752 (JP, A) 7-62502 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C22C 1/00, 45/10 B22D 23/06-27/04

Claims (5)

(57) [Claims] 1. A general _{formula: Zr 100-abc A a B} b C c ( however
A is one or more selected from Ti, Hf, Al, and Ga.
Is at least two elements, and B is selected from Fe, Co, Ni, and Cu.
One or more selected elements, C is Pd, Pt, A
u, Ag, or one or more elements selected from the group consisting of
A, b, and c in the formula are 5 ≦ a ≦ 2 in atomic ratio.
0, 20 ≦ b ≦ 40, 0 <c ≦ 10, and 30 ≦ a + b
+ C ≦ 70 and 100K or more
Temperature range of the supercooled liquid region (ΔT = crystallization temperature (Tx)
-Zirconium alloy having a glass transition temperature (Tg)
Is placed in a forced cooling mold having a bar-shaped molding cavity with an open upper surface , and the zirconium alloy extends from the upper surface in the molding cavity to the lower surface of the mold cavity by high-frequency induction heating, arc discharge, electron beam, laser or infrared irradiation. Forming a melting region melted in a cross section, and moving the melting region in the length direction of the forced cooling mold by relatively moving at least one of a heating heat source and the forced cooling mold in the direction of the bar. A method for producing a zirconium amorphous alloy rod material. 2. The method for producing a zirconium amorphous alloy bar according to claim 1, wherein the cross-sectional area of the zirconium amorphous alloy bar is 10 mm ² or more and the length is 50 mm or more. . 3. The method according to claim 1, wherein the forced cooling mold is a water-cooled mold or a gas-cooled mold. Wherein the general _{formula: Zr 100-abc A a B} b C c ( however,
A is one or two selected from Ti, Hf, Al, and Ga
B is one or more elements selected from Fe, Co, Ni, Cu, and C is Pd, Pt, Au,
Consisting of one or more elements selected from Ag,
A, b, and c in the formula are atomic ratios of 5 ≦ a ≦ 20, respectively.
20 ≦ b ≦ 40, 0 <c ≦ 10, and 30 ≦ a + b +
A temperature range of a supercooled liquid region having a composition satisfying c ≦ 70 and being 100 K or more (ΔT = crystallization temperature (Tx) −
Glass transition temperature (Tg)) and a cross-sectional area of 10 mm ²
A zirconium amorphous alloy bar formed by die casting and having a length of at least 50 mm . 5. An amorphous phase having a volume ratio of 50% or more to 100% or more.
The zirconium amorphous alloy cast by a mold according to claim 4, characterized in that the remaining crystalline phase has a particle size of 100 µm or less.