Nickel-vanadium alloy target grain refinement method

Abstract

The invention discloses a nickel-vanadium alloy target grain refinement method and an equal channel angular extrusion die, and belongs to the field of metal material machining severe plastic deformation. The method comprises the steps that a nickel-vanadium cast ingot is subjected to homogenizing annealing (1200 DEG C / 2 h, AC), then 8-pass extrusion is conducted through a BC path, and the total deformation is 165%. Each pass of extrusion is divided into three stages, the extrusion rates of the first four passes are the same, and the extrusion rates of the last four passes are relatively slow. The extrusion rate of each pass in the first four passes of extrusion is 10mm / s, 8mm / s and 6mm / s, and the extrusion rate of each pass in the last four passes of extrusion is 8mm / s, 6mm / s and 4mm / s. The equal channel angular extrusion die is composed of an L-shaped channel, the inner angle of the die is 120 degrees, and the outer angle of the die is 30 degrees. Then stress relief annealing (700 DEG C / 1 h, AC) is carried out; then large-deformation cold rolling is carried out, the deformation is 90%, and a sample is thinned to 3 mm; and then the plate is subjected to recrystallization annealing (550-850 DEG C / 1 h, AC). Compared with the prior art, the obtained structure is compact and has few defects, the structure is uniform, crystal grains are fine, and the strength is improved.

Description

Technical Field

[0001] The invention relates to a nickel-vanadium alloy target material grain refinement method, belonging to the technical field of large plastic deformation of metal material processing. Background Art

[0002] In the production of integrated circuits, pure gold is usually used as the surface conductive layer. However, gold and silicon wafers easily generate AuSi low-melting-point compounds, resulting in weak bonding between the gold and silicon interfaces. For this reason, researchers have proposed the idea of ​​adding a bonding layer on the surface of gold and silicon wafers. The commonly used bonding layer material is pure nickel. However, diffusion will occur between the nickel layer and the gold conductive layer, so a barrier layer is required to prevent diffusion between the gold conductive layer and the nickel bonding layer. In order to meet this requirement, the barrier layer needs to use a metal with a high melting point and must withstand a large current density. High-purity metal vanadium can meet this requirement. By adding 7wt.%±0.5wt.% of vanadium to nickel for smelting, a nickel-vanadium alloy ingot is obtained. Nickel-vanadium alloy is non-magnetic, which is conducive to magnetron sputtering. In the electronics and information industries, it has basically replaced pure nickel sputtering targets.

[0003] With the progress of society and the development of the semiconductor industry, the demand for nickel-vanadium targets in the electronics and information, integrated circuit, display and other industries is increasing. Sputtering nickel-vanadium targets require high purity, few impurities, uniform chemical composition, no segregation, no pores, uniform grain structure, and micron-level grain size. The grain size difference in a single sputtering target is required to be as small as possible. Although commercial nickel-vanadium targets have appeared in the industry, the nickel-vanadium targets prepared by existing methods have insufficient grain size and uneven structure, so there is an urgent need to find a new preparation process. Summary of the invention

[0004] The object of the present invention is to provide a method for grain refinement of a nickel-vanadium alloy target material, which specifically comprises the following steps:

[0005] (1) melting the nickel-vanadium ingot and then performing homogenization annealing;

[0006] (2) The surface of the nickel-vanadium alloy after homogenization annealing is evenly coated with graphene lubricant, and then placed in the equal-diameter angular extrusion die for extrusion, so that the billet completely passes through the channel corner of the equal-diameter angular extrusion die, completing an extrusion process, and the extrusion path is B C The sample was rotated 90° in the same direction between each pass, and then extruded for 8 passes along the path, with a total deformation of 165%;

[0007] During equal-diameter angular extrusion, each extrusion pass is divided into three stages, namely before deformation, during deformation, and after deformation. The rate is from fast to slow. The extrusion rate of each of the first four extrusion passes is 10mm / s, 8mm / s, and 6mm / s, and the extrusion rate of each of the last four extrusion passes is 8mm / s, 6mm / s, and 4mm / s. The extrusion rates of the first four passes are the same, and the extrusion rates of the last four passes are relatively slower; the extrusion rate of each pass is from fast to slow.

[0008] (3) Stress relief annealing was performed on the nickel-vanadium alloy after 8 passes of equal-diameter angular extrusion.

[0009] (4) The annealed nickel-vanadium alloy was subjected to large deformation cold rolling; the average grain size was about 1.4 μm.

[0010] (5) The nickel-vanadium alloy after rolling is subjected to recrystallization annealing.

[0011] Preferably, the V content in the nickel-vanadium alloy of the present invention is 7wt.%±0.5wt.%, the Ni content is 93wt.%±0.5wt.%, the purity of V is higher than 99.9%, the purity of nickel is 99.99%, and the purity of the nickel-vanadium ingot is 99.9%-99.995%.

[0012] Preferably, the size of the nickel-vanadium ingot in step (1) of the present invention is 30×30×50 mm, the homogenization annealing temperature is 1200° C., the holding time is 2 h, and then the ingot is cooled to room temperature in the furnace.

[0013] Preferably, in step (2) of the present invention, the blanking end of the sample is cut into a spherical shape for easy extrusion, and the equal-diameter angular extrusion die is composed of an L-shaped channel, the inner angle of the die is 120°, and the outer angle is 30°.

[0014] Preferably, the large deformation cold rolling in step (4) of the present invention is: low strain rate unidirectional rolling, the rolling rate is 8-16rpm, the deformation amount of the rolling pass is 25-30% during the first rolling pass, and the deformation amount of the rolling pass is 15-20% during the second rolling pass; after the third pass, the rolling deformation amount of each pass is not more than 5%, the cumulative cold rolling deformation amount is 90%, and the sample is thinned to 3mm.

[0015] Preferably, in step (3) of the present invention, the stress relief annealing temperature is 700° C., the annealing time is 1 hour, and then air cooling is performed.

[0016] Preferably, in step (5) of the present invention, the recrystallization annealing temperature is 550-850° C., the holding time is 1 hour, and then air-cooling to room temperature occurs. After the recrystallization annealing, the grain size is 2.4-12.6 μm.

[0017] Preferably, after the cold rolling described in step (4) of the present invention.

[0018] Preferably, in step (5) of the present invention, the recrystallization annealing temperature is 550-850° C., the holding time is 1 hour, and then air-cooling to room temperature occurs. After the recrystallization annealing, the grain size is 2.4-12.6 μm.

[0019] In the extrusion process of the present invention, rapid extrusion in the initial stage is mainly because the material has not yet undergone significant deformation. At this time, a faster extrusion rate can quickly introduce deformation, promote material flow and initial grain refinement; slow extrusion at the beginning of deformation: slowing down the rate helps to avoid stress concentration and local uneven deformation of the material caused by excessively rapid deformation, thereby reducing the formation of material defects and improving the uniformity of grain refinement; slower extrusion after complete deformation: further reducing the extrusion rate helps to stabilize the microstructure, reduce residual stress and defects caused by rapid deformation, and avoid microstructure unevenness or grain coarsening caused by excessively rapid deformation rate; the mold model used is simple and the mold is easy to remove. After extrusion molding, the cavity can be removed, and the cavity is divided into two left and right parts to facilitate material unloading; due to path B C The shear surface changes alternately in four directions. It is generally believed that path B C It has the most rapid and significant grain refinement effect.

[0020] Beneficial effects of the present invention:

[0021] (1) The homogenization annealing and equal-diameter angular extrusion adopted enable the material to achieve a sufficiently high deformation (8 passes) during the extrusion process, and the extrusion effect is good. Sufficient extrusion makes the nickel-vanadium alloy grains significantly refined and the strength improved; the structure is dense, pore-free, non-magnetic, with high sputtering stability, high coating efficiency, and high quality of deposited thin films.

[0022] (2) The extrusion rate of the last four passes is lower than that of the first four passes, mainly because the material is severely work-hardened after the four extrusion passes. Therefore, the extrusion rate of the last four passes is low. Three-stage extrusion with different rates can not only improve production efficiency, but also optimize the mechanical properties and microstructure of the material by finely controlling the deformation process of the material. The extrusion rate is from fast to slow, the purpose of which is to gradually reduce the work hardening during each extrusion process.

[0023] (3) The stress relief annealing and double-roll unidirectional low-strain rolling methods used enable the material to reach a sufficiently high deformation (90%) during the rolling deformation process without cracking the rolled plate. Sufficient cold deformation results in significant grain refinement of the plate. Recrystallization annealing causes recrystallization of the grains, with an average grain size of 2.4-12.6μm, fine grains, and uniform structure, making it suitable for a variety of sputtering requirements.

[0024] (4) The grain size obtained by two types of large plastic deformation, equal-diameter angular extrusion and multi-pass rolling, is small and uniform. The target material has stable ignition during sputtering and the sputtering process is stable, which can prepare high-performance target materials. The surface of the plate prepared by this method is smooth and flat, and only a small amount of machining is required to obtain the target material. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the three-stage extrusion of equal-channel angular extrusion described in the present invention.

[0026] Figure 2 This is the microstructure of the nickel-vanadium alloy target in Example 1 described in the present invention.

[0027] Figure 3 It is the grain orientation diagram and local orientation difference distribution diagram of the nickel-vanadium alloy target material in Example 1 described in the present invention.

[0028] Figure 4 This is the microstructure of the nickel-vanadium alloy target in Example 2 described in the present invention.

[0029] Figure 5 It is the grain orientation diagram and local orientation difference distribution diagram of the nickel-vanadium alloy target in Example 2 described in the present invention.

[0030] Figure 6 This is the microstructure of the nickel-vanadium alloy target in Comparative Example 1 described in the present invention.

[0031] Figure 7 It is the grain orientation diagram and local orientation difference distribution diagram of the nickel-vanadium alloy target in Comparative Example 1 described in the present invention.

[0032] Figure 8 This is the microstructure of the nickel-vanadium alloy target in Comparative Example 2 described in the present invention.

[0033] Fig. 9 It is the grain orientation diagram and local orientation difference distribution diagram of the nickel-vanadium alloy target in Comparative Example 2 described in the present invention.

[0034] Fig.10 This is the microstructure of the nickel-vanadium alloy target in Comparative Example 3 described in the present invention.

[0035] Fig.11 It is the grain orientation diagram and local orientation difference distribution diagram of the nickel-vanadium alloy target in Comparative Example 3 described in the present invention.

[0036] Fig.12 This is the microstructure of the nickel-vanadium alloy target in Comparative Example 4 described in the present invention.

[0037] Fig.13 This is the microstructure of the nickel-vanadium alloy target in Comparative Example 5 described in the present invention. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited to the contents described above.

[0039] In the nickel-vanadium alloy described in the embodiment of the present invention, the V content is 7wt.%±0.5wt.%, the Ni content is 93wt.%±0.5wt.%, the purity of V is higher than 99.9%, the purity of nickel is 99.99%, and the purity of the nickel-vanadium ingot is 99.9%-99.995%.

[0040] Example 1

[0041] A nickel-vanadium alloy target grain refinement method and an equal-channel angular extrusion die, the specific steps are as follows:

[0042] (1) The material of this embodiment is nickel-vanadium alloy. The size of the nickel-vanadium ingot is 30×30×50 mm. The nickel-vanadium ingot is first kept at 1200° C. for 2 h and then cooled to room temperature in the furnace.

[0043] (2) The surface of the nickel-vanadium alloy after homogenization annealing is evenly coated with graphene lubricant, and then placed in the equal-diameter angular extrusion die for extrusion, so that the billet completely passes through the channel corner of the equal-diameter angular extrusion die, completing an extrusion process, and the extrusion path is B C The method comprises the following steps: a) performing an equal-channel angular extrusion and extruding the sample along a path (the sample rotates 90° in the same direction between each pass), and then performing 8 extrusion passes according to the path, with a total deformation of 165%; b) performing equal-channel angular extrusion, wherein each extrusion pass is divided into three stages, and the extrusion rates of the first four passes are the same, while the extrusion rates of the last four passes are relatively slow; the extrusion rate of each pass is from fast to slow, and the extrusion rates of each of the first four passes are 10 mm / s, 8 mm / s, and 6 mm / s, and the extrusion rates of each of the last four passes are 8 mm / s, 6 mm / s, and 4 mm / s; and the equal-channel angular extrusion die is composed of an L-shaped channel, and the inner angle of the die is 120°, and the outer angle is 30°.

[0044] (3) The nickel-vanadium alloy after equal-diameter angular extrusion was subjected to stress relief annealing at 700°C for 1 h and then air-cooled; the purpose was to improve the plasticity of the material after large plastic deformation and prepare for subsequent rolling.

[0045] (4) The nickel-vanadium alloy after annealing is subjected to large deformation cold rolling. The cold deformation method is low strain rate unidirectional rolling, the rolling rate is 8-16rpm, the deformation amount of the rolling pass is 25% in the first rolling pass, and the deformation amount of the rolling pass is 15% in the second rolling pass. After the third pass, the rolling deformation amount of each pass is not more than 5%, the cumulative cold rolling deformation amount is 90%, and the sample is thinned to 3mm.

[0046] (5) The rolled nickel-vanadium alloy is subjected to recrystallization annealing at a temperature of 650°C, kept at this temperature for 1 hour, and then air-cooled.

[0047] from Figure 2 and Figure 3 It can be seen from the figure that the grains of this embodiment have been completely recrystallized, the grains are small, 2.4 μm, and the grain size is uniform and the roundness is good.

[0048] Comparative Example 5 and Example 1 are compared. The difference is that during the equal-channel angular extrusion process, the extrusion rate of the 8 passes is 8 mm / s. Although the grains of the comparative example have been completely recrystallized, the grain size is uneven due to the single extrusion rate. Compared with Example 1, the grain size is larger, and the effect is not as good as Example 1. In addition, during the equal-channel angular extrusion process, the flow of the material inside the die may not be completely uniform, resulting in inconsistent grain refinement inside the material, which will affect the final performance of the material. As the number of extrusions increases, the dislocation density inside the material increases, resulting in work hardening, which will increase the difficulty of subsequent extrusion.

[0049] Example 2

[0050] A nickel-vanadium alloy target grain refinement method and an equal-channel angular extrusion die, the specific steps are as follows:

[0051] (1) The material of this embodiment is nickel-vanadium alloy. The size of the nickel-vanadium ingot is 30×30×50 mm. The nickel-vanadium ingot is first kept at 1200° C. for 2 h and then cooled to room temperature in the furnace.

[0052] (2) The surface of the nickel-vanadium alloy after homogenization annealing is evenly coated with graphene lubricant, and then placed in the equal-diameter angular extrusion die for extrusion, so that the billet completely passes through the channel corner of the equal-diameter angular extrusion die, completing an extrusion process, and the extrusion path is B C The method comprises the following steps: a first extrusion path (the sample is rotated 90° in the same direction between each pass), and then 8 extrusion passes are performed according to the path, with a total deformation of 165%; each extrusion pass is divided into three stages during equal-diameter angular extrusion, and the extrusion rates of the first four passes are the same, while the extrusion rates of the last four passes are relatively slow; the extrusion rate of each pass is from fast to slow, and the extrusion rates of each of the first four extrusion passes are 10 mm / s, 8 mm / s, and 6 mm / s, and the extrusion time is 0.5 s, 3 s, and 5 s; the extrusion rates of each of the last four extrusion passes are 8 mm / s, 6 mm / s, and 4 mm / s, and the extrusion time is 0.6 s, 4 s, and 5 s; the equal-diameter angular extrusion die is composed of an L-shaped channel, and the inner angle of the die is 90° and the outer angle is 30°.

[0053] (3) The nickel-vanadium alloy after equal-diameter angular extrusion was subjected to stress relief annealing at 700°C for 1 h and then air-cooled; the purpose was to improve the plasticity of the material after large plastic deformation and prepare for subsequent rolling.

[0054] (4) The nickel-vanadium alloy after annealing is subjected to large deformation cold rolling. The cold deformation method is low strain rate unidirectional rolling, the rolling rate is 8-16rpm, the deformation amount of the rolling pass is 30% in the first rolling pass, and the deformation amount of the rolling pass is 20% in the second rolling pass; after the third pass, the rolling deformation amount of each pass is not more than 5%, the cumulative cold rolling deformation amount is 90%, and the sample is thinned to 3mm.

[0055] (5) The rolled nickel-vanadium alloy is subjected to recrystallization annealing at a temperature of 750°C, kept at this temperature for 1 hour, and then air-cooled.

[0056] from Figure 4 and Figure 5 It can be seen that the grains of this embodiment have been completely recrystallized, and the grains are small, 2.8μm, and the grain size is uniform and the roundness is good.

[0057] Comparative Example 1

[0058] (1) The material of this embodiment is nickel-vanadium alloy. The size of the nickel-vanadium ingot is 30×30×50 mm. The nickel-vanadium ingot is first kept at 1200° C. for 2 h and then cooled to room temperature with the furnace.

[0059] (2) The surface of the nickel-vanadium alloy after homogenization annealing is evenly coated with graphene lubricant, and then placed in the equal-diameter angular extrusion die for extrusion, so that the billet completely passes through the channel corner of the equal-diameter angular extrusion die, completing an extrusion process, and the extrusion path is B C The method comprises the following steps: a first extrusion path (the sample is rotated 90° in the same direction between each pass), and then 8 extrusion passes are performed according to the path, with a total deformation of 165%; each extrusion pass is divided into three stages during equal-diameter angular extrusion, and the extrusion rates of the first four passes are the same, while the extrusion rates of the last four passes are relatively slow; the extrusion rate of each pass is from fast to slow, and the extrusion rates of each of the first four extrusion passes are 10 mm / s, 8 mm / s, and 6 mm / s, and the extrusion time is 0.5 s, 3 s, and 5 s; the extrusion rates of each of the last four extrusion passes are 8 mm / s, 6 mm / s, and 4 mm / s, and the extrusion time is 0.6 s, 4 s, and 5 s; the equal-diameter angular extrusion die is composed of an L-shaped channel, and the inner angle of the die is 90° and the outer angle is 30°.

[0060] (3) The nickel-vanadium alloy after equal-diameter angular extrusion was subjected to stress relief annealing at 700°C for 1 h and then air-cooled; the purpose was to improve the plasticity of the material after large plastic deformation and prepare for subsequent rolling.

[0061] (4) The nickel-vanadium alloy after annealing is subjected to large deformation cold rolling. The cold deformation method is low strain rate unidirectional rolling, the rolling rate is 8-16rpm, the deformation amount of the rolling pass is 25% in the first rolling pass, and the deformation amount of the rolling pass is 15% in the second rolling pass. After the third pass, the rolling deformation amount of each pass is not more than 5%, the cumulative cold rolling deformation amount is 90%, and the sample is thinned to 3mm.

[0062] from Figure 6 and Figure 7 It can be seen that the grains of the comparative example are small, 1.4 μm, but the grain size is uneven and the internal stress is large, so it is not suitable for subsequent production of target materials.

[0063] Comparative Example 2

[0064] (1) The material of this embodiment is nickel-vanadium alloy, and the size of the nickel-vanadium ingot is 30×30×50 mm. The nickel-vanadium ingot is first kept at 1200° C. for 2 h and then cooled to room temperature with the furnace;

[0065] (2) The surface of the nickel-vanadium alloy after homogenization annealing is evenly coated with graphene lubricant, and then placed in the equal-diameter angular extrusion die for extrusion, so that the billet completely passes through the channel corner of the equal-diameter angular extrusion die, completing an extrusion process, and the extrusion path is B C The method comprises the following steps: a) performing an equal-channel angular extrusion and extruding the sample along a path (the sample rotates 90° in the same direction between each pass), and then performing 8 extrusion passes according to the path, with a total deformation of 165%; b) performing equal-channel angular extrusion, wherein each extrusion pass is divided into three stages, and the extrusion rates of the first four passes are the same, while the extrusion rates of the last four passes are relatively slow; the extrusion rate of each pass is from fast to slow, and the extrusion rates of each of the first four passes are 10 mm / s, 8 mm / s, and 6 mm / s, and the extrusion rates of each of the last four passes are 8 mm / s, 6 mm / s, and 4 mm / s; and the equal-channel angular extrusion die is composed of an L-shaped channel, and the inner angle of the die is 120°, and the outer angle is 30°.

[0066] (3) The nickel-vanadium alloy after equal-diameter angular extrusion was subjected to stress relief annealing at 700°C for 1 h and then air-cooled; the purpose was to improve the plasticity of the material after large plastic deformation and prepare for subsequent rolling.

[0067] (4) The nickel-vanadium alloy after annealing is subjected to large deformation cold rolling. The cold deformation method is low strain rate unidirectional rolling, the rolling rate is 8-16rpm, the deformation amount of the rolling pass is 25% in the first rolling pass, and the deformation amount of the rolling pass is 15% in the second rolling pass. After the third pass, the rolling deformation amount of each pass is not more than 5%, the cumulative cold rolling deformation amount is 90%, and the sample is thinned to 3mm.

[0068] (5) The rolled nickel-vanadium alloy is subjected to recrystallization annealing at a temperature of 550°C, kept at this temperature for 1 hour, and then air-cooled.

[0069] from Figure 8 and Fig. 9 It can be seen that the grains of this comparative example are small, 1.3 μm, but the annealing temperature is near the recrystallization temperature of the nickel-vanadium alloy. Its structure is similar to that of comparative example 1, the grain size is uneven, and the internal stress is large, so it is not suitable for subsequent production of target materials.

[0070] Comparative Example 3

[0071] (1) The material of this embodiment is nickel-vanadium alloy, and the size of the nickel-vanadium ingot is 30×30×50 mm. The nickel-vanadium ingot is first kept at 1200° C. for 2 h and then cooled to room temperature with the furnace;

[0072] (2) The surface of the nickel-vanadium alloy after homogenization annealing is evenly coated with graphene lubricant, and then placed in the equal-diameter angular extrusion die for extrusion, so that the billet completely passes through the channel corner of the equal-diameter angular extrusion die, completing an extrusion process, and the extrusion path is B C The path (the sample rotates 90° in the same direction between each pass), and then 8 passes of extrusion are performed according to the path, and the total deformation is 165%; during equal-channel angular extrusion, each extrusion is divided into three stages for extrusion, and the extrusion rate of the first four passes is the same, and the extrusion rate of the last four passes is relatively slower; the extrusion rate of each pass is from fast to slow, and the extrusion rate of each pass in the first four extrusions is 10mm / s, 8mm / s, and 6mm / s, and the extrusion rate of each pass in the last four extrusions is 8mm / s, 6mm / s, and 4mm / s; the equal-channel angular extrusion die is composed of an L-shaped channel, the inner angle of the die is 120°, and the outer angle is 30°;

[0073] (3) The nickel-vanadium alloy after equal-diameter angular extrusion was subjected to stress relief annealing at 700°C for 1 h and then air-cooled; the purpose was to improve the plasticity of the material after large plastic deformation and prepare for subsequent rolling.

[0074] (4) The nickel-vanadium alloy after annealing is subjected to large deformation cold rolling. The cold deformation method is low strain rate unidirectional rolling, the rolling rate is 8-16rpm, the deformation amount of the rolling pass is 25-30% in the first rolling pass, and the deformation amount of the rolling pass is 15-20% in the second rolling pass. After the third pass, the rolling deformation of each pass is not more than 5%, the cumulative cold rolling deformation is 90%, and the sample is thinned to 3mm.

[0075] (5) The rolled nickel-vanadium alloy is subjected to recrystallization annealing at a temperature of 850°C, kept at this temperature for 1 hour, and then air-cooled.

[0076] from Fig.10 Fig.11It can be seen that although the grains of the comparative example have been completely recrystallized, the internal stress has been released, and the dislocation density has been reduced; however, the annealing temperature is too high, causing the grains to grow rapidly and the grain size is too large (12.6μm), so it is not suitable for subsequent production of target materials.

[0077] Comparative Example 4

[0078] A nickel-vanadium sputtering target is prepared by rolling with a large deformation and a low strain rate as described in Example 4 of patent CN117840220A, comprising the following steps:

[0079] (1) The nickel-vanadium ingot is kept at 1100±30°C for 3 hours and then cooled to room temperature.

[0080] (2) The annealed nickel-vanadium is subjected to large deformation cold rolling. The deformation of the first rolling pass is 20%, and the deformation of the second rolling pass is 15%. After the cumulative deformation is about 35%, the deformation of each rolling pass is no more than 5%. The final rolling deformation is 95%, the billet is thinned to 1.5 mm, and the equivalent effect is 2.60.

[0081] (3) Annealing the rolled plate at a temperature of 600±30°C, keeping the temperature for 1 hour and then cooling it in air;

[0082] Fig.12 It is observed that the grains of the comparative example have been completely recrystallized, and the grain size is less than 50 μm. Through testing, it is found that although the deformation amount has reached 95%, the grain size is larger than that of the nickel-vanadium alloy prepared in Examples 1 and 2.

[0083] Comparative Example 5

[0084] (1) The material of this comparative example is a nickel-vanadium alloy, and the size of the nickel-vanadium ingot is 30×30×50 mm. The nickel-vanadium ingot is first kept at 1200° C. for 2 h and then cooled to room temperature with the furnace;

[0085] (2) The surface of the nickel-vanadium alloy after homogenization annealing is evenly coated with graphene lubricant, and then placed in the equal-diameter angular extrusion die for extrusion, so that the billet completely passes through the channel corner of the equal-diameter angular extrusion die, completing an extrusion process, and the extrusion path is B C The path (the sample was rotated 90° in the same direction between each pass), and then 8 extrusions were performed according to the path, with an extrusion rate of 10 mm / s and a total deformation of 165%. The equal-channel angular extrusion die consists of an L-shaped channel with an inner angle of 120° and an outer angle of 30°;

[0086] (3) After equal-diameter angular extrusion, the nickel-vanadium alloy was subjected to stress relief annealing at 700°C for 1 h and then air-cooled. The purpose is to improve the plasticity of the material after large plastic deformation and prepare for subsequent rolling.

[0087] (4) The nickel-vanadium alloy after annealing is subjected to large deformation cold rolling. The cold deformation method is low strain rate unidirectional rolling, the rolling rate is 8-16rpm, the deformation amount of the rolling pass is 25-30% in the first rolling pass, and the deformation amount of the rolling pass is 15-20% in the second rolling pass. After the third pass, the rolling deformation of each pass is not more than 5%, the cumulative cold rolling deformation is 90%, and the sample is thinned to 3mm.

[0088] (5) The rolled nickel-vanadium alloy is subjected to recrystallization annealing at a temperature of 650°C, kept at this temperature for 1 hour, and then air-cooled.

[0089] from Fig.13 It can be seen that although the grains of the comparative example have been completely recrystallized, the grain size is uneven due to the single extrusion rate. Compared with Example 1, the grain size is larger and the effect is not as good as Example 1.

Claims

1. A method for grain refinement of nickel-vanadium alloy target material, It is characterized in that The specific steps include: (1) melting the nickel-vanadium ingot and then performing homogenization annealing; (2) The surface of the nickel-vanadium alloy after homogenization annealing is evenly coated with graphene lubricant, and then placed in the equal-diameter angular extrusion die for extrusion, so that the billet completely passes through the channel corner of the equal-diameter angular extrusion die, completing an extrusion process, and the extrusion path is B C The sample was rotated 90° in the same direction between each pass, and then extruded for 8 passes along the path, with a total deformation of 165%; During equal channel angular extrusion, each extrusion is divided into three stages: before deformation, during deformation, and after deformation. The rate is from fast to slow. The extrusion rate of each of the first four extrusions is 10mm / s, 8mm / s, and 6mm / s, and the extrusion rate of each of the last four extrusions is 8mm / s, 6mm / s, and 4mm / s. (3) stress relief annealing of the nickel-vanadium alloy after 8 passes of equal-diameter angular extrusion; (4) performing large deformation cold rolling on the annealed nickel-vanadium alloy; (5) The nickel-vanadium alloy after rolling is subjected to recrystallization annealing.

2. The method for grain refinement of a nickel-vanadium alloy target according to claim 1, Features: The content of V in the nickel-vanadium alloy is 7wt.%±0.5wt.%, the content of Ni is 93wt.%±0.5wt.%, the purity of V is higher than 99.9%, the purity of nickel is 99.99%, and the purity of the nickel-vanadium ingot is 99.9%-99.995%.

3. The method for grain refinement of a nickel-vanadium alloy target according to claim 1, Features: The size of the nickel-vanadium ingot in step (1) is 30×30×50 mm, the homogenization annealing temperature is 1200° C., the holding time is 2 h, and then the ingot is cooled to room temperature in the furnace.

4. The method for grain refinement of a nickel-vanadium alloy target according to claim 1, Features: In step (2), the blanking end of the sample is cut into a spherical shape for easy extrusion. The equal-diameter angular extrusion die is composed of an L-shaped channel, the inner angle of the die is 120°, and the outer angle is 30°.

5. The method for grain refinement of a nickel-vanadium alloy target according to claim 1, Features: The large deformation cold rolling in step (4) is: low strain rate unidirectional rolling, the rolling rate is 8-16rpm, the deformation amount of the rolling pass is 25-30% during the first rolling pass, and the deformation amount of the rolling pass is 15-20% during the second rolling pass; after the third pass, the rolling deformation amount of each pass is not more than 5%, the cumulative cold rolling deformation amount is 90%, and the sample is thinned to 3mm.

6. The method for grain refinement of a nickel-vanadium alloy target according to claim 1, Features: In step (3), the stress relief annealing temperature is 700° C., the annealing time is 1 h, and then air cooling is performed.

7. The nickel-vanadium alloy target grain refinement method and equal-diameter angular extrusion die according to claim 1, Features: In step (5), the recrystallization annealing temperature is 550-850° C., the holding time is 1 hour, and then air-cooling to room temperature occurs. After the recrystallization annealing, the grain size is 2.4-12.6 μm.

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