CN-120519730-B - Method for preparing CuTi alloy strip based on ultrasonic-assisted solidification and liquid nitrogen cold rolling

Abstract

The invention relates to the technical field of a preparation method of a high-end voice coil motor elastic sheet, in particular to a method for preparing a CuTi alloy strip based on ultrasonic-assisted solidification and liquid nitrogen cold rolling, which comprises the following steps of proportioning and determining the approximate content range of each element of copper-titanium alloy; vacuum induction smelting, applying ultrasonic fields with different powers to perform ultrasonic oscillation during alloy smelting and solidification, performing solution treatment on the obtained copper-titanium alloy cast ingot, then performing water cooling, performing liquid nitrogen cold rolling, wherein the copper-titanium alloy plate is always in a low-temperature environment during rolling to obtain a high-density nano twin crystal structure, and placing the copper-titanium strip into a vacuum atmosphere furnace to perform aging treatment to obtain the final copper-titanium alloy strip. The preparation method solves the problems that the copper-titanium alloy casting blank is easy to generate contradiction of component segregation and coarse primary phase structure in the prior method, and the structure inheritance is caused in the subsequent deformation process, so that the strength and the conductivity of the copper-titanium alloy strip are influenced, and the cooperative promotion is difficult.

Inventors

• ZHANG ZHE
• Gao Nanxi
• Lei Zuodong
• Cui Shangkun
• LIU JIAN
• ZOU JUNTAO
• LIANG SHUHUA

Assignees

• 西安理工大学

Dates

Publication Date

20260505

Application Date

20250623

Claims (6)

1. 1. The method for preparing the CuTi alloy strip based on ultrasonic-assisted solidification and liquid nitrogen cold rolling is characterized by comprising the following steps of: step 1, batching, wherein the content of each element of the titanium bronze alloy is 3-6% of Ti and 96-97% of Cu in percentage by mass; Step 2, vacuum induction smelting is carried out, and raw materials are put into vacuum smelting equipment for smelting; Step 3, applying ultrasonic fields with different powers to carry out ultrasonic oscillation on the alloy in the step 2 during smelting and solidification to obtain copper-titanium alloy ingots; step 4, carrying out solution treatment on the obtained copper-titanium alloy cast ingot, and then carrying out water cooling; step 5, cold rolling copper-titanium alloy by liquid nitrogen, namely cooling the copper-titanium alloy, rolling after the roller is cooled to a certain temperature, and performing corresponding cooling operation in the rolling process and after each pass is completed until the required deformation is reached, so as to obtain a cold rolled blank; And 6, placing the copper-titanium alloy strip into a vacuum atmosphere furnace for aging treatment to obtain the final copper-titanium alloy strip.
2. 2. The method for preparing the CuTi alloy strip based on ultrasonic-assisted solidification and liquid nitrogen cold rolling according to claim 1, wherein the specific process of the step 2 is vacuum induction smelting, namely, putting the raw materials weighed in the step (1) into vacuum smelting equipment for vacuum smelting, wherein the vacuum degree is 5 multiplied by 10 -3 - 8×10 -3 Pa, and the smelting current is 22A-26A.
3. 3. The method for preparing the CuTi alloy strip based on ultrasonic-assisted solidification and liquid nitrogen cold rolling according to claim 1, wherein the specific process of the step 3 is that the alloy in the step (2) is subjected to ultrasonic vibration by applying ultrasonic fields with different powers during smelting and solidification, the ultrasonic amplitude is changed along with the change of the power, the frequency of the applied ultrasonic wave is 20-25kHz, and the ultrasonic power is not more than 2700W.
4. 4. The method for preparing the CuTi alloy strip based on ultrasonic-assisted solidification and liquid nitrogen cold rolling, which is characterized by comprising the specific process of step 4, wherein the copper-titanium alloy cast ingot obtained in step 3 is subjected to solution heat treatment, the solution temperature is 750-900 ℃, the temperature of a sample is increased along with a furnace, the solution time is 1-12h, and water cooling is carried out after the solution is finished.
5. 5. The method for preparing the CuTi alloy strip based on ultrasonic-assisted solidification and liquid nitrogen cold rolling, which is characterized by comprising the specific processes of preparing liquid nitrogen for rolling, cooling the copper-titanium alloy obtained in the step (4) in a container filled with liquid nitrogen for 40-70 minutes, starting a rolling mill after the copper-titanium alloy is fully cooled, spraying liquid nitrogen on a roller for 5-10 minutes to cool the roller to a certain temperature, wherein the linear speed of the roller in the rolling process is 60-240 mm/s, the rolling reduction rate of each pass is 15-25%, the copper-titanium alloy strip is cooled in the liquid nitrogen for 10-30 minutes after each pass of rolling is completed, and repeating the rolling process until the copper-titanium alloy plate reaches the required deformation amount, thereby obtaining a copper-titanium alloy cold rolled blank.
6. 6. The method for preparing the CuTi alloy strip based on ultrasonic-assisted solidification and liquid nitrogen cold rolling, which is disclosed in claim 1, is characterized in that the specific process of the step 6 is that the copper-titanium alloy strip obtained in the step 5 is placed into a vacuum atmosphere furnace, and is subjected to heat preservation for 1-24 hours at 400-500 ℃ to obtain the final copper-titanium alloy strip.

Description

Method for preparing CuTi alloy strip based on ultrasonic-assisted solidification and liquid nitrogen cold rolling Technical Field The invention belongs to the technical field of preparation methods of high-end Voice Coil Motor (VCM) shrapnel, and particularly relates to a method for preparing a CuTi alloy strip based on ultrasonic-assisted solidification and liquid nitrogen cold rolling. Background The high-strength high-elasticity copper alloy is favored in the tip fields of high-end electronic communication, aerospace and the like by virtue of high strength, high elasticity, excellent electric conduction, heat conduction and non-magnetic properties. At present, beryllium copper alloy is dominant for a long time by virtue of excellent performance in the field of current-carrying conductive elastic materials, and is known as an 'elastic material king'. However, beryllium is a strategic metal, and resources are scarce and exploitation and utilization are extremely difficult. Along with the increasing strictness of environmental protection standards, the defects of the beryllium copper alloy are gradually highlighted, particularly the toxicity of beryllium element threatens the environment and the human health, beryllium-containing dust and compounds possibly generated in the smelting and processing process are classified into 1-class cancerogenic substances by the international agency for research on cancer (IARC), the beryllium copper alloy is poor in stress relaxation resistance and conductive stability and difficult to meet the use requirements under the high-temperature environment, and in addition, the beryllium copper alloy has long production period and low yield, so that the price of the product is high. In view of this, it is urgent to develop a novel green copper alloy having high strength and high elastic properties. To address these issues, researchers have been looking for alternative materials to beryllium copper. Copper titanium alloys are considered as one of the most potential alternative materials due to their similar excellent properties, such as good heat resistance, fatigue resistance, corrosion resistance and high temperature stress resistance. However, the strength and conductivity of the copper-titanium alloy strip prepared by the traditional process can not meet the service requirements of a high-end Voice Coil Motor (VCM) shrapnel and an electric connector, and the copper-titanium alloy strip has become a key difficult problem for restricting the application of the copper-titanium alloy strip. Therefore, there is an urgent need to solve the problem that the copper-titanium alloy is difficult to cooperatively improve the strength and the electrical conductivity. Aiming at the difficult problems faced in preparing copper-titanium alloy strips, related research reports exist at present. The patent application number is 202310778835.9, which provides an ultra-high-strength conductive copper-titanium alloy and a preparation method thereof. The method is characterized by comprising the following steps of (1) sequentially smelting and casting raw materials of copper-titanium alloy to obtain copper-titanium alloy ingots, (2) sequentially carrying out solution treatment, hot rolling and first time-efficiency treatment on the copper-titanium alloy ingots obtained in the step (1) to obtain copper-titanium alloy plates, and (3) sequentially carrying out first cold rolling, second aging treatment and second cold rolling on the copper-titanium alloy plates obtained in the step (2) to obtain the ultrahigh-strength conductive copper-titanium alloy. The invention takes Cu as a matrix, and can effectively improve the strength and the conductivity of the alloy by adding alloy elements Cr and Mg, wherein the Mg element is dissolved in the matrix to play a solid solution strengthening role, cr and Ti can form Cr2Ti intermetallic compound, the solid solution Ti content is reduced, the conductivity of the alloy is improved, the intermetallic compound prevents dislocation movement in the later rolling process, the dislocation density is improved, the strength and the conductivity of the alloy are improved, the volume fraction of a beta-Cu 4Ti precipitated phase is improved on the premise of reducing the production cost by combining combined aging treatment, the conductivity of the alloy is greatly improved by combining hot rolling and cold rolling, and the invention is favorable for obtaining high density, and the beta-Cu 4Ti phase is uniformly distributed, so that the strength and the conductivity of the copper-titanium alloy are improved. patent application number 202280054776.4 provides a copper titanium alloy comprising, by weight, at least 90% copper, 5% -7% titanium, and 0.25% -0.5% iron. The copper-titanium alloy has excellent ductility in solution annealing tempering and has high yield strength after aging treatment. The alloy according to the invention can replace Cu Be alloys in any very h