钛合金高速旋转超声椭圆振动侧铣削切屑特征和刀具磨损研究

Research on the Characteristics of Chips and Tool Flank Wear in High-speed Rotary Ultrasonic Elliptical Machining for Side Milling of Ti-6Al-4V

难加工材料钛合金在采用传统铣削方式时,随着切削速度的增加,切削力和切削温度都迅速增加,使得切削条件恶化并加速刀具磨损,从而导致刀具过早失效。将超声椭圆振动加工技术引入到高速铣削中,进行了钛合金高速旋转超声椭圆振动侧铣削试验。从切屑特征以及刀具后刀面磨损两个方面研究了高速超声椭圆振动铣削参数匹配对钛合金加工的影响。首先基于高速超声椭圆振动铣削过程中刀具-工件的运动学特点推导出高速超声椭圆振动铣削加工参数与振动参数间的匹配关系,然后利用本实验室自行研制的超声椭圆振动铣削装置进行了不同参数匹配关系下的验证性切削试验。试验结果表明:合理的参数匹配使得超声椭圆振动铣削在高速条件下依然能够实现分离型断续切削加工。相比普通铣削加工,分离型的高速超声椭圆振动铣削能够获得更加微细的切屑,切削热能够被及时地带走;良好的切削条件使得刀具的后刀面磨损均匀而缓慢,从而延长刀具的使用寿命;高速超声椭圆振动铣削能够有效地提高生产效率。

For the difficult-to-cut material titanium alloy, as the cutting speed increases in the traditional milling method, the cutting force and the cutting temperature increase rapidly, which deteriorate cutting conditions and accelerate tool wear resulting in premature tool failure and poor machining quality. The ultrasonic elliptical vibration cutting technology is introduced into high-speed milling, and then the high-speed rotary ultrasonic elliptical machining for side milling(UEVM) of Ti-6Al-4V is carried out. The effects of high-speed ultrasonic elliptical vibration milling parameter matching on titanium alloy machining are studied from two aspects of chip characteristics and tool flank wear. Firstly, based on the kinematics of tool-work in high-speed ultrasonic elliptical vibration milling, the matching relationship between milling parameters and vibration parameters is derived. Then, the verification cutting tests with different parameter matching relationship are carried out by using the ultrasonic elliptical vibration milling device developed by our laboratory. The test results show that high-speed ultrasonic elliptical machining for side Milling can achieve separate-type cutting through reasonable matching of cutting parameters and vibration parameters, making it possible to apply the rotary ultrasonic elliptical vibration milling method in the high-speed range. Compared with common milling, the separate-type high-speed ultrasonic elliptical vibration milling can obtain finer chips and cutting heat is easy to be taken away;in addition, tool flank wear become more even and slowly due to better cutting condition, which can prolong the service life of milling tool and effectively increase production efficiency.