纳秒光纤激光精密切割超弹镍钛合金薄板工艺技术的研究

Research on Nanosecond Fiber Laser Precision Cutting Process Technology of Superelastic Nitinol Sheets

超弹镍钛合金广泛应用于医疗器械、航空航天和电子行业。在实际应用中,需要对超弹镍钛合金进行精密切割,才能满足结构、尺寸和性能的要求。针对镍钛合金使用传统刀具加工困难、电火花线切割速度较慢、连续脉冲激光切割精度差、热影响区较大等问题,采用纳秒光纤激光对镍钛合金薄板进行了精密切割,系统研究了激光切割工艺参数、热处理工艺与切割质量的关系。研究结果表明,纳秒光纤激光切割未经热处理的镍钛板,采用优化的激光工艺参数可以满足尺寸精度的要求,切割速度可达25 mm/s,但切口挂渣比较严重。对镍钛板进行热处理后,采用优化的纳秒光纤激光切割工艺,可以满足尺寸精度的要求,切口无挂渣现象,可避免复杂的后处理过程,大大提高生产效率。同时,热处理工艺提高了镍钛板的超弹性。

Superelastic nitinol is widely used in medical equipment, aerospace and electronics industry. In practical applications, precision cutting of superelastic nitinol is required to meet the requirements of structure, size and performance. In view of the problems such as difficulty in cutting nitinol with traditional cutting tools, slow cutting speed with EDM, poor cutting accuracy and large heat affected zone with continuous pulse laser, nanosecond fiber laser was used to precisely cut superelastic nitinol sheets. The relationship between laser cutting process parameters, heat treatment process and cutting quality was systematically studied. The results show that the use of nanosecond fiber laser to cut unheat-treated nitinol sheets with optimized laser process parameters can meet the requirements of dimensional accuracy, and the cutting speed can reach 25 mm/s, but the slag hanging on the cutting surface is serious. After heat treatment, the nitinol sheets are cut by an optimized nanosecond fiber laser process, which can meet the requirements of dimensional accuracy. There is no hanging slag phenomenon in the cutting surface, which can avoid the complicated post processing and greatly improve the production efficiency. At the same time, the heat treatment process improves the superelasticity of nitinol sheets.