A method for preparing semi-hard beryllium nickel-titanium alloy strip

Abstract

This invention relates to the field of metal material processing technology, specifically to a method for preparing semi-hard beryllium nickel-titanium alloy strip, comprising the following steps: heating a beryllium nickel-titanium alloy ingot to 1000-1050℃ and holding it for 1-2 hours, then hot rolling it in a hot rolling mill to obtain a beryllium nickel-titanium sheet; subjecting the beryllium nickel-titanium sheet to a primary quenching at a temperature of 1000-1050℃ for a holding time equal to the thickness of the beryllium nickel-titanium sheet × k1, using water as the quenching medium; subjecting the beryllium nickel-titanium sheet to a primary cold rolling in a cold rolling mill to obtain a beryllium nickel-titanium strip; subjecting the beryllium nickel-titanium strip to a second quenching at a temperature of 1000-1050℃ for a holding time equal to the thickness of the beryllium nickel-titanium strip × k2, using water as the quenching medium; and subjecting the beryllium nickel-titanium strip to a secondary cold rolling in a cold rolling mill for a secondary cold rolling process of 45-50%, to obtain a semi-hard beryllium nickel-titanium strip. This invention employs a precise process combination of "two quenchings + two cold rollings" to achieve alloy microstructure homogenization and solid solution strengthening through quenching, while eliminating work hardening caused by each rolling pass.

Description

Technical Field

[0001] This invention relates to the field of metal material processing technology, specifically to a method for preparing semi-hard beryllium nickel-titanium alloy strip. Background Technology

[0002] Beryllium-nickel alloys are high-performance elastic alloys formed by adding beryllium to nickel as the base metal. With their excellent comprehensive properties, including high strength, high elasticity, high temperature resistance, and corrosion resistance, they have become indispensable structural materials in key fields such as aerospace, precision instruments, and high-end electronics. To further improve the mechanical properties and hardening effect of the alloy, existing technologies often introduce titanium into beryllium-nickel alloys to construct beryllium-nickel-titanium (Be-Ni-Ti) ternary alloys with superior performance, thus adapting to the needs of more advanced applications.

[0003] In practical applications, processing high-performance alloys into strips of varying thicknesses is one of their main applications. Therefore, the preparation process of beryllium-based alloy strips has always been a key focus of industry research. Several existing technologies exist for preparing beryllium-based alloy strips. For example, Chinese patent CN106566950A discloses a high-strength, high-elasticity, and high-corrosion-resistant beryllium-nickel alloy and its manufacturing method. This method targets titanium-free binary beryllium-nickel alloys, employing the traditional process route of "vacuum melting - hot rolling - intermediate annealing - finished product rolling." Intermediate annealing at 880-890℃ eliminates work hardening, softening the material to ensure smooth subsequent rolling, ultimately obtaining a Y-state beryllium-nickel alloy product. This process provides a feasible solution for preparing beryllium-nickel alloy strips, but it has significant limitations when adapted to beryllium-nickel-titanium ternary alloys.

[0004] Existing technologies still face many unresolved technical challenges in the preparation of beryllium nickel-titanium alloy strips: On the one hand, while the introduction of titanium enhances the mechanical properties of the alloy, it also significantly increases the inherent hardness and work hardening rate of the beryllium nickel-titanium alloy. Conventional annealing processes (such as the 880-890℃ intermediate annealing used in CN106566950A) are no longer effective in softening the material. During multi-pass rolling, problems such as rolling difficulties, material cracking, or excessive equipment load are prone to occur, seriously affecting production efficiency and product qualification rate. On the other hand, existing technologies lack strip rolling processes specifically for high-hardness beryllium nickel-titanium alloys, especially lacking standardized preparation methods that can stably obtain "semi-hard" products with specific elasticity and strength matching. Summary of the Invention

[0005] To address the problems existing in the prior art, the present invention provides a method for preparing semi-hard beryllium nickel-titanium alloy strip.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] A method for preparing a semi-hard beryllium nickel-titanium alloy strip includes the following steps:

[0008] (1) Hot rolling: The beryllium nickel titanium alloy ingot is heated to 1000-1050℃ and held for 1-2 h. Then it is placed in a hot rolling mill for hot rolling to obtain beryllium nickel titanium plate. The amount of rolling in one pass is 30-50% of the initial thickness of the beryllium nickel titanium plate.

[0009] (2) First quenching: The beryllium nickel titanium plate obtained in step (1) is first quenched at a temperature of 1000-1050℃ and a holding time of = thickness of beryllium nickel titanium plate × k1. The quenching medium is water.

[0010] (3) First cold rolling: The beryllium nickel titanium plate after step (2) is placed into a cold rolling mill for the first cold rolling to obtain beryllium nickel titanium strip;

[0011] (4) Secondary quenching: The beryllium nickel titanium strip obtained in step (3) is quenched again. The quenching temperature is 1000-1050℃, the holding time is = beryllium nickel titanium strip thickness × k2, and the quenching medium is water.

[0012] (5) Secondary cold rolling: The beryllium nickel titanium strip after step (4) is placed into a cold rolling mill for secondary cold rolling. The secondary cold rolling amount is 45-50%, and beryllium nickel titanium semi-hard strip is obtained.

[0013] Furthermore, during the hot rolling process in step (1), the beryllium nickel titanium plate needs to be returned to the furnace for reheating, and the reheating time is 10-15 minutes.

[0014] Furthermore, in step (2), the value of k1 ranges from 1.5 to 1.7 min / mm.

[0015] Furthermore, in step (3), the number of cold rolling cycles is no less than 5.

[0016] Furthermore, in step (4), the value of k2 ranges from 10 to 12 min / mm.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] This invention provides a method for preparing semi-hard beryllium nickel-titanium alloy strip, employing a precise process combination of "two quenchings + two cold rollings." The quenching process achieves alloy microstructure homogenization and solid solution strengthening, while eliminating work hardening generated during each rolling pass. Compared to existing annealing processes that are difficult to adapt, this significantly reduces rolling resistance, avoids material cracking, rolling difficulties, and excessive equipment load, and greatly improves production efficiency and product qualification rate. Furthermore, by strictly limiting the secondary cold rolling to 45-50% and using quenching and holding time parameters adapted to the material thickness, a standardized process system is constructed, enabling the stable preparation of strips with specific elasticity and strength matching. The semi-hard beryllium nickel-titanium alloy strip fills the gap in the existing technology for the lack of a standardized preparation method for this ternary alloy semi-hard product, precisely meeting the specific performance requirements of high-end fields. In addition, the process route of this invention is specifically designed for beryllium nickel-titanium ternary alloys, and the process logic and parameter settings are more in line with the material characteristics. Through multi-step process synergy, not only is the rolling process guaranteed to proceed smoothly, but the internal structure of the alloy is also optimized, improving the overall performance of the product. The process flow is clear, the key parameters are clearly quantified, and there is no need for complex auxiliary equipment and operations. It is easy to achieve precise industrial control and batch replication, which helps to reduce production costs and promote the large-scale application of high-performance beryllium nickel-titanium materials. Attached Figure Description

[0019] The embodiments of the present invention will be further described below with reference to the accompanying drawings, wherein:

[0020] Figure 1 A process flow diagram of the present invention is shown. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0022] Reference Appendix Figure 1 A method for preparing semi-hard beryllium nickel-titanium alloy strip includes the following steps:

[0023] (1) Hot rolling: The beryllium nickel titanium alloy ingot is heated to 1000-1050℃ and held for 1-2 h. Then it is placed in a hot rolling mill for hot rolling to obtain beryllium nickel titanium plate. The amount of rolling in one pass is 30-50% of the initial thickness of the beryllium nickel titanium plate.

[0024] (2) First quenching: The beryllium nickel titanium plate obtained in step (1) is first quenched at a temperature of 1000-1050℃ and a holding time of = thickness of beryllium nickel titanium plate × k1. The quenching medium is water.

[0025] (3) First cold rolling: The beryllium nickel titanium plate after step (2) is placed into a cold rolling mill for the first cold rolling to obtain beryllium nickel titanium strip;

[0026] (4) Secondary quenching: The beryllium nickel titanium strip obtained in step (3) is quenched again. The quenching temperature is 1000-1050℃, the holding time is = beryllium nickel titanium strip thickness × k2, and the quenching medium is water.

[0027] (5) Secondary cold rolling: The beryllium nickel titanium strip after step (4) is placed into a cold rolling mill for secondary cold rolling. The secondary cold rolling amount is 45-50%, and beryllium nickel titanium semi-hard strip is obtained.

[0028] In one embodiment of the present invention, during the hot rolling process of step (1), the beryllium nickel titanium plate needs to be returned to the furnace for reheating, and the reheating time is 10-15 minutes.

[0029] In one embodiment of the present invention, in step (2), the value of k1 ranges from 1.5 to 1.7 min / mm.

[0030] In one embodiment of the present invention, in step (3), the number of cold rolling cycles is not less than 5.

[0031] In one embodiment of the present invention, in step (4), the value of k2 is in the range of 10-12 min / mm.

[0032] Example 1

[0033] A method for preparing a semi-hard beryllium nickel-titanium alloy strip includes the following steps:

[0034] (1) Hot rolling: The beryllium nickel titanium alloy ingot is heated to 1050℃ and held for 2 hours. Then it is placed in a hot rolling mill for hot rolling. The hot rolling sequence is 30mm→20mm→14mm. It is then placed back into the heating furnace for 15 minutes of reheating. The subsequent hot rolling process is 10mm→6mm→4mm. After each rolling is completed, it is promptly returned to the furnace for 10 minutes of reheating to obtain beryllium nickel titanium plate.

[0035] (2) First quenching: The 4mm beryllium nickel titanium plate obtained in step (1) is subjected to first quenching at a temperature of 1050℃ and a holding time of 6min. The quenching medium is water.

[0036] (3) First cold rolling: The 4mm beryllium nickel titanium plate after step (2) is placed into a cold rolling mill for the first cold rolling. The processing sequence is 4mm→2mm→1.2mm→0.8mm→0.6mm→0.5mm→0.45mm→0.39mm to obtain beryllium nickel titanium strip;

[0037] (4) Secondary quenching: The beryllium nickel titanium strip obtained in step (3) is quenched again at a temperature of 1000℃ and a holding time of 4min. The quenching medium is water.

[0038] (5) Secondary cold rolling: The beryllium nickel titanium strip after step (4) is placed into a cold rolling mill for secondary cold rolling. The rolling sequence is 0.4mm→0.35mm→0.3mm→0.26mm→0.22mm→0.2mm to obtain beryllium nickel titanium semi-hard strip.

[0039] After rolling, the thickness of the strip was measured at multiple points. The thickness error was within ±0.05mm, and the resulting semi-hard beryllium nickel titanium alloy strip was 0.2mm thick.

[0040] Example 2

[0041] A method for preparing a semi-hard beryllium nickel-titanium alloy strip includes the following steps:

[0042] (1) Hot rolling: The beryllium nickel titanium alloy ingot is heated to 1000℃ and held for 1.5 h. Then it is placed in a hot rolling mill for hot rolling. The hot rolling sequence is 20mm→15mm→10mm. It is then placed back into the heating furnace for 15min to reheat. The subsequent hot rolling process is 10mm→7mm→5mm. After each rolling is completed, it is promptly returned to the furnace for 10min to reheat, thus obtaining beryllium nickel titanium plate.

[0043] (2) First quenching: The 5mm beryllium nickel titanium plate obtained in step (1) is subjected to first quenching at a temperature of 1000℃ and a holding time of 8min. The quenching medium is water.

[0044] (3) First cold rolling: The 5mm beryllium nickel titanium plate after step (2) is placed into a cold rolling mill for the first cold rolling. The processing sequence is 5mm→3mm→2mm→2.0mm→1.6mm→1.3mm→1.0mm to obtain beryllium nickel titanium strip;

[0045] (4) Secondary quenching: The beryllium nickel titanium strip obtained in step (3) is quenched again at a temperature of 1000℃ and a holding time of 12min. The quenching medium is water.

[0046] (5) Secondary cold rolling: The beryllium nickel titanium strip after step (4) is placed into a cold rolling mill for secondary cold rolling. The rolling sequence is 1.0mm→0.8mm→0.72mm→0.66mm→0.6mm→0.55mm→0.5mm to obtain beryllium nickel titanium semi-hard strip.

[0047] After rolling, the thickness of the strip was measured at multiple points. The thickness error was within ±0.05mm, and the resulting strip was a 0.5mm semi-hard beryllium nickel titanium alloy strip.

[0048] Example 3

[0049] A method for preparing a semi-hard beryllium nickel-titanium alloy strip includes the following steps:

[0050] (1) Hot rolling: The beryllium nickel titanium alloy ingot is heated to 1050℃ and held for 1 h. Then it is placed in a hot rolling mill for hot rolling. The hot rolling sequence is 10mm→6mm→4mm. It is then placed back into the heating furnace for 10min of reheating. The subsequent hot rolling process is 4mm→2.8mm→1.9mm. After each rolling is completed, it is promptly returned to the furnace for 10min of reheating to obtain beryllium nickel titanium plate.

[0051] (2) First quenching: The 1.9mm beryllium nickel titanium plate obtained in step (1) is subjected to first quenching at a temperature of 1000℃ and a holding time of 3min. The quenching medium is water.

[0052] (3) First cold rolling: The 1.9mm beryllium nickel titanium plate after step (2) is placed into a cold rolling mill for the first cold rolling. The processing sequence is 1.9mm→1.5mm→1.1mm→0.8mm→0.6mm to obtain beryllium nickel titanium strip;

[0053] (4) Secondary quenching: The beryllium nickel titanium strip obtained in step (3) is quenched again at a temperature of 1000℃ and a holding time of 7min. The quenching medium is water.

[0054] (5) Secondary cold rolling: The beryllium nickel titanium strip after step (4) is placed into a cold rolling mill for secondary cold rolling. The rolling sequence is 0.6mm→0.52mm→0.45mm→0.4mm→0.35mm→0.3mm to obtain beryllium nickel titanium semi-hard strip.

[0055] After rolling, the thickness of the strip was measured at multiple points. The thickness error was within ±0.05mm, and the resulting semi-hard beryllium nickel titanium alloy strip was 0.3mm thick.

[0056] This invention provides a method for preparing semi-hard beryllium nickel-titanium alloy strip, employing a precise process combination of "two quenchings + two cold rollings." The quenching process achieves alloy microstructure homogenization and solid solution strengthening, while eliminating work hardening generated during each rolling pass. Compared to existing annealing processes that are difficult to adapt, this significantly reduces rolling resistance, avoids material cracking, rolling difficulties, and excessive equipment load, and greatly improves production efficiency and product qualification rate. Furthermore, by strictly limiting the secondary cold rolling to 45-50% and using quenching and holding time parameters adapted to the material thickness, a standardized process system is constructed, enabling the stable preparation of strips with specific elasticity and strength matching. The semi-hard beryllium nickel-titanium alloy strip fills the gap in the existing technology for the lack of a standardized preparation method for this ternary alloy semi-hard product, precisely meeting the specific performance requirements of high-end fields. In addition, the process route of this invention is specifically designed for beryllium nickel-titanium ternary alloys, and the process logic and parameter settings are more in line with the material characteristics. Through multi-step process synergy, not only is the rolling process guaranteed to proceed smoothly, but the internal structure of the alloy is also optimized, improving the overall performance of the product. The process flow is clear, the key parameters are clearly quantified, and there is no need for complex auxiliary equipment and operations. It is easy to achieve precise industrial control and batch replication, which helps to reduce production costs and promote the large-scale application of high-performance beryllium nickel-titanium materials.

[0057] The foregoing descriptions have outlined some exemplary embodiments of the present invention. It is understood that these embodiments are merely illustrative and do not constitute a limitation on the scope of protection of the present invention. Features in these embodiments can be rearranged in suitable ways, and the resulting solutions remain within the scope of protection claimed by the present invention. All other embodiments obtained by those skilled in the art based on the foregoing embodiments without inventive effort, i.e., all modifications, equivalent substitutions, and improvements made within the spirit and principles of this application, fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing a semi-hard beryllium nickel-titanium alloy strip, characterized in that, Includes the following steps: Hot rolling: The beryllium nickel titanium alloy ingot is heated to 1000-1050℃ and held for 1-2 hours. Then it is placed in a hot rolling mill for hot rolling to obtain beryllium nickel titanium sheet. The rolling amount in a single pass is 30-50% of the initial thickness of the beryllium nickel titanium sheet. First quenching: The beryllium nickel titanium plate obtained in step (1) is first quenched at a temperature of 1000-1050℃ and a holding time of = beryllium nickel titanium plate thickness × k1. The quenching medium is water. First cold rolling: The beryllium nickel titanium plate after step (2) is placed into a cold rolling mill for first cold rolling to obtain beryllium nickel titanium strip; Secondary quenching: The beryllium nickel titanium strip obtained in step (3) is quenched again at a temperature of 1000-1050℃ and a holding time of = beryllium nickel titanium strip thickness × k2. The quenching medium is water. Secondary cold rolling: The beryllium nickel titanium strip after step (4) is placed into a cold rolling mill for secondary cold rolling. The secondary cold rolling amount is 45-50%, and beryllium nickel titanium semi-hard strip is obtained.

2. The method for preparing a semi-hard beryllium nickel-titanium alloy strip according to claim 1, characterized in that, Step (1) During the hot rolling process, the beryllium nickel titanium plate needs to be returned to the furnace for reheating, and the reheating time is 10-15 minutes.

3. The method for preparing a semi-hard beryllium nickel-titanium alloy strip according to claim 1, characterized in that, In step (2), the value of k1 ranges from 1.5 to 1.7 min / mm.

4. The method for preparing a semi-hard beryllium nickel-titanium alloy strip according to claim 1, characterized in that, In step (3), the number of cold rolling cycles shall not be less than 5.

5. The method for preparing a semi-hard beryllium nickel-titanium alloy strip according to claim 1, characterized in that, In step (4), the value of k2 is in the range of 10-12 min / mm.

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