JP5905265B2 - High production efficiency amorphous sheet manufacturing method and manufacturing equipment - Google Patents

Description

The claimed invention relates to a manufacturing method and the like for mass-producing amorphous thin plates (including metal glass, including those having an amorphous ratio of not 100%) as industrial materials.

  It has been nearly 50 years since amorphous alloys were introduced to the world, and there have been reports of cases with excellent properties such as corrosion resistance, toughness, wear resistance, magnetism, hydrogen storage, and catalysts. Amorphous production methods include centrifugal liquid quenching, single-roll liquid quenching, twin-roll liquid quenching and other foil strips, gas / water atomization powders, sputtering, vapor deposition, and rotating liquid jetting. For example, the production of wire.

  However, when manufacturing large size (large thickness, large width) amorphous materials with a composition with low amorphous forming ability, the above method is limited in size due to insufficient cooling rate or low production efficiency. For this reason, it has been an environment in which amorphous materials are not widely used as industrial materials. On the other hand, a technique applying the thermal spraying method was invented and reported in Patent Documents 1 to 4.

  Patent Document 1 reports a method of forming a metal glass laminate by a high-speed flame spraying method using metal glass powder as a raw material. Patent Documents 2 to 4 report a method of forming an amorphous laminate by rapidly cooling and laminating molten particles. In any of the methods, since a laminate is formed, there is no size limit. However, it is actually difficult to efficiently produce a high-quality film without cracks. Furthermore, when only the laminated body (amorphous thin plate) separated from the base material is desired, the technical hurdle becomes higher.

JP 2006-214000 JP 2008-43869 A JP 2008-174784 Japanese Patent No. 4579317

If you want to obtain an amorphous thin plate with a thickness of about 300 μm using the thermal spraying method, for example, form an amorphous film on the surface of the plate-like substrate, and intentionally peel off the amorphous film from the substrate There is a way to make it. In this case, in order to reduce the adhesion, the thermal spraying conditions, the material of the base material, the base material temperature, and the surface treatment method will be adjusted, but stress concentration occurs at the edge of the plate. Peeling is likely to occur. Fig. 1 shows a photograph of the exfoliation site, which has a small heat capacity, and crystallizes as the temperature rises due to the thermal spray flame. On the other hand, if the adhesive force is too high, it is difficult to peel off the substrate and the amorphous thin plate, and cracking may occur in the amorphous thin plate when forcibly peeling off. Fig. 2 is a picture of the situation.
Although a method of dissolving only the base material with a corrosive solution can be considered, it is not suitable for mass production in consideration of production efficiency and environmental load.

  Therefore, the present invention establishes a method for producing a high-quality (low porosity, high amorphization rate) amorphous thin plate with high production efficiency. Here, the production efficiency of the thin plate is defined as the production efficiency of the thin plate satisfying the target size and quality.

  In the present invention, in order to prevent the amorphous thin plate from peeling off from the substrate during film formation, a roll-shaped substrate is used as the substrate to be sprayed. By using a roll-shaped substrate, it is possible to prevent the occurrence of concentrated stress generated in the amorphous thin plate during film formation, so that the rate of occurrence of peeling of the amorphous thin plate until the completion of film formation is reduced. The roundness of the base roll is not critical, but it is better to be close to a perfect circle. Further, the size of the base roll is not limited, and can be made large as long as preheating up to the target temperature is possible.

As shown in FIG. 3, the base roll needs to be rotated during film formation. The spray gun is moved in the horizontal horizontal direction (that is, the axial length direction of the base material) from the front with respect to the rotating base material roll while keeping the axis horizontal. The operation of this spray gun is repeated at the target substrate temperature to form a film to the target thickness. In the present invention, as an example, the rotation speed of the substrate roll was 184 rpm, and the moving speed of the spray gun was 90 cm / min.
In this regard, another rolling roll is placed in contact with the peripheral surface of the base roll, and film formation is performed while rolling down with an appropriate load (at this time, the thermal spray gun is placed near the contact portion of the two rolls. It may be reciprocated in the axial direction of the base material so as to eject the powder material. By doing so, the porosity of the thin plate to be manufactured can be reduced and the surface can be smoothed.
The base roll shown in FIG. 3 is set with the axis maintained in the horizontal direction, but the base roll is set and rotated so that the axis is vertical, and the thermal spray gun is moved vertically and vertically. In this example, an amorphous thin plate was produced under repeated conditions (in the direction of the axial length of the base material) and, for example, a base roll rotation speed of 1 rpm and a spray gun moving speed of 9000 cm / min. Was maintained in the horizontal direction, and the same success rate and quality could be achieved as the amorphous thin plate produced at a rotation speed of the substrate roll of 184 rpm and a moving speed of the spray gun of 90 cm / min. Accordingly, the relationship between the axial direction of the setting of the base roll and the moving direction of the spray gun may be in the horizontal horizontal direction or in the vertical vertical direction.

  The adhesion between the amorphous thin plate and the substrate is strongly influenced by the properties of the substrate surface and the substrate surface temperature during film formation. Adhesion has a positive correlation with the roughness of the substrate surface and the substrate surface temperature. In order to achieve both prevention of thin plate peeling during film formation and thin plate peeling after film formation, appropriate adhesion, that is, a combination of an appropriate substrate surface roughness and substrate surface temperature is required.

  Usually, blasting using an alumina abrasive or the like is applied in the surface treatment of thermal spraying. However, the surface becomes rough with blasting, and the adhesion is too high to peel the thin plate after film formation. This phenomenon is not greatly improved by blasting with fine alumina (# 100) and suppressing the surface roughness to some extent. In the present invention, it has been found that a surface polished with a # 180 nylon nonwoven fabric type polishing tool is desirable.

  The substrate surface temperature during film formation is a factor that affects adhesion, but this also affects the quality of the thin plate (porosity, amorphization rate), so the quality of the produced thin plate (porosity, amorphization) Rate) confirmation is important. In the present invention, as a result of combining with an appropriate surface treatment, it has been found that the adhesive strength becomes strong when the substrate temperature is 450 ° C., and it is difficult to peel the thin plate from the substrate roll after film formation. Although the adhesive force tends to decrease as the substrate temperature decreases, the porosity of the thin plate increases at 160 ° C. Therefore, considering the quality, the substrate temperature is desirably 180 ° C. or higher.

  With the production method of the present invention, an amorphous thin plate of high quality (low porosity, high amorphous ratio) can be produced with high production efficiency. Using a roll-shaped base material makes it easier to adjust the adhesion of the amorphous thin plate / base material than a plate-shaped base material (it does not peel off during film formation and can be easily peeled off after film formation is complete). Thus, the yield of the amorphous thin plate is improved. The temperature of the substrate can also be easily stabilized without auxiliary equipment such as a jig as compared with the plate-shaped substrate. Furthermore, the base material roll can be reused, which is advantageous in terms of cost, such as a small required area when considering continuous production equipment. From these, amorphous thin plate materials can be mass-produced as industrial products and deployed.

It is the photograph of the external appearance which the film | membrane peeled in the middle of film-forming. It is the photograph of the external appearance which the thin plate broke in the location with strong adhesive force at the time of thin plate peeling. It is a figure which shows the rotating apparatus which attached the base material roll. It is a figure which shows sticking of the heat-resistant tape (having the length more than roll width) to a base material roll. It is a figure which shows the heat resistant tape (having the length below a roll width) sticking to a base material roll. It is a figure which shows the edge cutting location of a thin-plate both sides. It is a figure which shows the thin plate peeling operation | work by metal foil. It is a side view which shows the use condition of an amorphous film forming apparatus. It is a diagram which shows the relationship between a base-material roll temperature and an amorphization rate. It is a cross-sectional photograph of the produced thin plate. FIG. 5 is a diagram showing a roughness curve of measurement of substrate surface roughness after polishing alumina blast (# 20) + # 180 nylon nonwoven fabric. It is an external appearance photograph of the produced amorphous thin plate. It is a figure of the mass production facility of an amorphous thin plate.

In the present invention, a base roll made of SKD11 having a size of φ198 mm × width 109 mm was used. The base roll is attached to the rotating device shown in FIG. 3 so that the runout does not occur. In this state, alcohol cleaning and various surface treatments were performed on the surface of the substrate roll. The contents are shown in Table 1. However, only the blasting in the content column of Table 1 is performed before the base roll is attached to the rotating device.
Next, as shown in FIG. 4, a heat-resistant tape was attached to one place of the substrate roll after the surface treatment so as to be a separation starting point after film formation. The heat-resistant tape was processed into a size of 10 mm width x 150 mm length and affixed so that the width direction dimension could be completely covered at one place on the outer peripheral surface of the base roll. After the film formation, the thin plate can be easily peeled off from the base roll with a metal foil or a scraper (see FIG. 7). Further, in order to prevent the thin plate and the substrate roll from being peeled off more stably until the film formation is completed, it is possible to apply a heat resistant tape as shown in FIG. With this method, on the outer periphery of the base material roll, there are places where the thin plates are connected in a complete circle (in FIG. 5, three places), so the possibility of peeling from the heat-resistant tape part during film formation is lower. .

  As the thermal spray gun, a gun having a function of rapidly cooling molten powder particles reported in Patent Document 4 was used. In an inert gas atmosphere, the raw metal powder is melted using the heat generated from the combustion gas and the fluidity of the carrier gas, and injected through a required nozzle to create an ultrafine melted droplet jet of the raw metal. Then, a refrigerant gas or a refrigerant mist is sprayed on the dissolved droplet jet and sprayed and collided on a required base material to deposit, and a complete amorphous film or an amorphous phase and a crystal structure phase are mixed at a predetermined ratio. Create a film. The specific structure of the spray gun is as shown in FIG. 8, in which the raw metal powder and the combustion gas are injected from the inside of the cylindrical body that is a double pipe, and the cooling gas or Inject refrigerant mist. At this time, depending on the composition of the raw metal powder, it is also possible to obtain a film having a nanocrystalline structure with a crystal grain size of less than 100 nm. As shown, nitrogen gas was used as the refrigerant, and acetylene / oxygen was used as the fuel. The spray gun was automatically controlled by a robot, and the spray gun moving speed (moving speed in the axial direction of the substrate) during film formation was set at 90 cm / min.

The powder for thermal spraying was prepared by a gas atomizing method, the composition was Ni ₇₂ Mo _4.5 Nb ₁₀ B ₁₃ Cu _0.5 (at%), and the particle size was classified to + 63 / −88 μm. This powder has been confirmed to have an amorphization rate of 19% from the heat generation energy value measured with a DSC apparatus (DSC7020 manufactured by SII).

The substrate roll is rotated by the rotating device shown in FIG. 3, preheating is performed up to the target temperature, and thermal spraying is immediately performed. The rotation speed of the substrate roll was constant at 184 rpm. Further, in order to prevent the temperature rise of the base roll during film formation, cooling air is jetted from both sides, and the base roll (rim section) is applied to the inner peripheral surface of the rim section of the base roll. ) Was controlled on the outer peripheral surface. Thermal spraying is performed up to a predetermined number of reciprocating spray guns so that the film is formed to the target thickness, and the film forming operation is completed. At this time, the rotation of the base material roll is also stopped. In addition, the base-material roll temperature measured the surface of the roll outer periphery continuously with the radiation thermometer.

Next, the thin plate peeling stage is entered. As shown in FIG. 6, the joint portion of the both sides of the thin plate with the end face of the base roll is scraped with an air grinder, and the both sides of the thin plate formed on the outer peripheral surface of the roll and the base roll are cut.

  In order to peel the thin plate, the heat-resistant tape attached to the base roll for the starting point is peeled off. Here, a slight gap is formed between the thin plate / base roll at the starting point. As shown in FIG. 7, a metal foil having a length equal to or greater than the width of the base roll is inserted into the gap, and the thin plate / base roll joining interface is continuously peeled off. Finally, the thin plate / base roll can be completely separated to obtain a single amorphous thin plate. In the present invention, an amorphous thin plate having a thickness of 300 μm × width 105 mm × length 600 mm was successfully produced.

Here, the relationship between the temperature of the base roll and the surface treatment becomes important. If the adhesion strength is insufficient, the film / substrate roll peels off during the film formation, and if the adhesion strength is excessive, the thin plate / substrate roll cannot be peeled after the film formation is completed. Table 2 shows the relationship.

The surface treatment numbers in Table 2 are the same as those in Table 1.
From Table 2, it was found that the condition of surface treatment No. 3 (those subjected to non-woven polishing after blasting) can separate the thin plate from the base material roll after film formation in the widest base material roll temperature range. Further, the amorphous thin plate to be produced is formed at a base roll temperature of about 200 ° C. for the initial thickness of about 20 μm, and the rest is formed by raising the base roll temperature (for example, a non-thickness of 300 μm in thickness). When producing an amorphous thin plate, 20 μm in the thickness direction from the amorphous thin plate / base roll interface is formed at a base roll temperature of 200 ° C., then re-preheated, and the rest on the amorphous thin plate surface. By forming a film with a thickness of 280 μm at a substrate roll temperature of 350 ° C., it is possible to more easily peel a high-quality (low porosity) amorphous thin plate from the substrate roll.

In order to confirm the structure of the obtained thin plate, crystallization heat generation energy ΔH (thin plate) was obtained with a DSC apparatus (DSC7020 manufactured by SII). Divide by the crystallization heat energy ΔH (ribbon) measured by Ni ₇₂ Mo _4.5 Nb ₁₀ B ₁₃ Cu _0.5 ribbon with 100% amorphization rate, which was prepared in advance by single roll liquid quenching method, Were determined.
Amorphization rate (%) = [ΔH (thin plate) / ΔH (ribbon)] x 100
FIG. 9 shows the relationship between the amorphization rate of the thin plate and the substrate roll temperature. Here, it can be seen that when the substrate roll temperature is 160 to 400 ° C., the amorphization rate is 90% or more. In this temperature (base roll) range, the desired amorphization rate can be achieved.
In addition, when reducing the amorphousization rate of the amorphous thin plate, it can be achieved by reducing the amount of the refrigerant or reducing the rotation speed of the base roll under the thermal spraying conditions described in Patent Document 4, so It is easy to obtain a thin plate with a rate of less than 90%. Specifically, in Patent Document 4, the pressure of nitrogen gas used as a refrigerant is desirably 0.25 MPa or more, but the pressure of this nitrogen gas is reduced to less than 0.25 MPa. In the same patent document, 280 mm / sec is cited as an example of the moving speed of the spray gun, but the rotation speed of the base roll is set so that the relative speed between the spray gun and the base surface is lower than this. The spraying conditions, such as lowering, are selected.

  Next, in order to confirm the denseness of the thin plate, cross-sectional observation and porosity measurement were performed. The porosity is affected by the substrate roll temperature during film formation. Specifically, there is a negative correlation between the substrate roll temperature and the porosity of the thin plate. FIG. 10 shows a thin plate cross-sectional photograph when the substrate roll temperature is 160, 200, 300 ° C., but when the substrate temperature reaches 160 ° C., the porosity exceeds 5%. Judging from quality, it becomes a defective product. Therefore, in order to produce a dense thin plate, a substrate roll temperature exceeding 160 ° C. is required.

As described above, when the conditions for producing the amorphous thin plate are comprehensively judged from the separation property of the thin plate / base roll (production efficiency), the amorphous ratio of the thin plate, and the denseness of the thin plate (quality), alumina Preheating and temperature maintenance for the base roll surface-treated with # 180 non-woven cloth after blasting according to (# 20), with the outer peripheral surface temperature exceeding 160 ° C and lower than 450 ° C (preferably 180 ° C or higher and 400 ° C or lower) When a film is formed on a substrate roll using the film forming apparatus shown in FIG. 8 (Patent Document 4) and then separated from the substrate roll, a high-quality amorphous thin plate is produced with high production efficiency. it can. In addition, once blasting is performed as a surface treatment on the substrate roll, it is not necessary until the dirt becomes severe (about 10 times), so the surface treatment during that time can be done only by polishing # 180 nonwoven fabric. It becomes.
When the substrate surface roughness after polishing this # 180 nonwoven fabric was measured 6 times with a reference length of 2.4 mm, Ra was 2.5 to 4.0 μm. This value is a level between ▽▽ and ▽▽▽ in the finishing symbol of mechanical drawing. FIG. 11 is a roughness curve actually measured.
When 25 amorphous thin plates (thickness 300 μm × width 105 mm × length 600 mm) were repeatedly produced, the success rate was 100% and the production time was 30 minutes / sheet. When an amorphous thin plate is obtained using a plate-like substrate, peeling of the thin plate / base material during film formation, and conversely, excessive adhesion of the thin plate / base material leads to cracking of the thin plate or remaining on the base material. Therefore, such production efficiency could not be achieved. FIG. 12 shows a photograph of the appearance of the Ni ₇₂ Mo _4.5 Nb ₁₀ B ₁₃ Cu _0.5 amorphous thin plate produced using the base roll as described above.

Production of an amorphous thin plate using a substrate roll according to the present invention can be applied by changing the size of the substrate roll or using the amorphous forming apparatus described in FIG. 8 (Patent Document 4). That is, if the size of the base roll is increased and the number of amorphous forming apparatuses is increased, it is possible to mass-produce amorphous thin plates. Tables 3 and 13 show the specifications and diagrams of the equipment that can be assumed. The equipment shown in FIG. 13 will be described. First, the surface of the cylindrical roll is treated with a brush roll (rough) and a brush roll (finish) to an appropriate roughness. The appropriate roughness is such that the film and the cylindrical roll are bonded during film formation with the cylindrical nozzle type spray gun, and the amorphous thin plate can be easily peeled from the cylindrical roll with the peeling roll and scraper. A coating starts to be formed on the cylindrical roll from the cylindrical nozzle type spray gun at the lower right of the brush roll (finish), and is sequentially laminated by the cylindrical nozzle type spray gun at the subsequent stage. Since the number of cylindrical nozzle spray guns is large and the cylindrical roll is expected to be higher than the target temperature, an internal cooling air nozzle is installed for temperature control, and the temperature of the cylindrical roll rises with the air blown from this. Suppress. The amorphous thin plate peeled from the cylindrical roll by the peeling roll and the scraper passes through the soaking furnace and the rolling roll after the shape is corrected by the leveler. When the amorphous thin plate to be manufactured is metallic glass, the flatness of the thin plate can be improved and the porosity can be reduced by heating to the supercooled liquid and rolling in that state. In trimming, in order to obtain an amorphous thin plate having a required width, the width is accurately cut, and the amorphous thin plate is wound into a coil shape by a winder. If necessary, the entire width of the amorphous thin plate is cut with a shaver. It is possible to obtain a final product such as a fuel cell separator, for example, by pressing at a supercooled liquid temperature after the rolling roll (amorphous thin plate molding, flatness improvement, porosity reduction) and punching. is there. The surface of the cylindrical roll exposed by the peeling roll and the scraper comes into contact with the brush roll (rough) and the brush roll (finish) again, and the above-described amorphous thin plate process is repeated. By using such equipment, a high-quality amorphous thin plate can be continuously produced in the longitudinal direction. As described above, the base roll does not change the production success rate and quality of the amorphous thin plate regardless of whether the axis is in the horizontal or vertical direction. The installation direction can be selected. In addition, the line speed can be increased by adding more cylindrical nozzle spray guns.

Claims (7)

Amorphous material in which a flame containing raw metal powder is sprayed from a spray gun toward the base material, the metal powder is melted by the flame, and the metal powder and flame are cooled with a cooling gas before reaching the base material. A film forming device is arranged around a roll-shaped substrate,
While rotating the base material and suppressing the temperature rise of the base material, using the above forming apparatus, a single type or a plurality of types of metal powder or alloy powder, or raw material metal powder composed of a mixed powder thereof, Connect directly or indirectly on the substrate to form the film on the outer peripheral surface of the substrate,
Furthermore, the said membrane | film | coat is isolate | separated from a base material with the peeling roll pressed on the said membrane | film | coat, and the scraper inserted under the said membrane | film | coat, The manufacturing method of the amorphous thin plate characterized by the above-mentioned. 2. The method for producing an amorphous thin plate according to claim 1 , wherein a plurality of the forming apparatuses are arranged around a roll-shaped base material and used at the same time . 3. The method for producing an amorphous thin plate according to claim 1 or 2 , wherein the outer peripheral surface of the roll-shaped base material is subjected to non-woven fabric polishing after blasting. The roll-shaped base material has a rim on the outer periphery, and the base material is preheated and cooled by blowing air from the inside of the rim during the formation of the film. The method for producing an amorphous thin plate according to any one of claims 1 to 3, wherein the outer peripheral surface of the material is maintained at a temperature higher than 160 ° C and lower than 450 ° C. The raw material metal powder _{Ni 72 Mo 4.5 Nb 10 B 13} Cu 0.5 by injected from the spray gun, as claimed in any one of claims 1 to 4, characterized in that to obtain an amorphous sheet of the chemical composition A method for producing an amorphous sheet. Before starting the formation of the film, a heat-resistant tape having a length extending over the entire width of the outer peripheral surface is attached to one place on the outer peripheral surface of the roll-shaped base material, or a length shorter than the entire width. 6. The method for producing an amorphous thin plate according to any one of claims 1 to 5 , wherein the heat-resistant tape is divided and pasted so as not to be connected to each other. The method of manufacturing according to the manufacturing method described in any one of claim 1 to 6 Therefore, the amorphous thin plate, characterized in that the production of amorphous sheet which is mixed amorphous and crystalline in any ratio .