基于温度场模拟TiNiTa记忆合金涂层工艺参数选择

Research on the paramenters of TiNiTa memory alloy coating based on temperature field simulation

以获得TC4钛合金表面高质量TiNiTa涂层为目标,使用ANSYS WORKBENCH软件、采用3D高斯热源,对激光熔覆TiNiTa粉末过程进行数值模拟仿真,研究其温度场云图分布;并研究激光功率、扫描速度、离焦量对温度场的影响。结果表明,在能量密度为1698 J/mm^(2)时熔覆层组织致密细小、与基体呈现良好的冶金结合;熔池中心的最高温度随着激光功率的增大而增大,随着热源移动速度和离焦量的增大而减小;另外,TC4钛合金表面的耐腐蚀被明显改善。模拟与试验结合确定激光熔覆的最优工艺参数为:激光功率100 W、扫描速度2.5 mm/s、离焦量10 mm、脉宽5 ms、频率10 Hz;通过分析可知能量密度是影响熔覆层组织及性能的重要因素,仿真模型的正确性及方法的可行性亦可得到试验验证。

To obtain high-quality TiNiTa coating on the surface of TC4 titanium alloy,using ANSYS WORKBENCH software and 3D Gaussian heat source,numerical simulation of the laser cladding TiNiTa powder process was carried out;and the temperature field cloud pattern distribution,the effects of laser power,scanning speed and defocus length on the temperature field were studied.The results show that the microstructure of the cladding layer was compact and fine with good metallurgical bonding to the substrate when the energy density was 1698 J/mm^(2).The maximum temperature in the center of molten pool increased with the increase of laser power and decreased with the increase of heat source moving speed and defocus length.In addition,the corrosion resistance of TC4 titanium alloy surface was significantly improved.The optimal process parameters were determined by combining simulation and experiment:laser power was 100 W,scanning speed was 2.5 mm/s,defocus length was 10 mm,pulse width was 5 ms,and frequency was 10 Hz.In addition,the analysis shows that the energy density is an important factor affecting the structure and performance of the cladding layer,and the correctness of the simulation model and feasibility of the method can also be verified by experiments.