八面钻超声振动钻削钛合金出口毛刺形成机理

钛合金在传统麻花钻常规钻孔后,会产生较大的孔出口毛刺,这将导致孔出口去毛刺困难且影响紧固件装配质量。本文引入一种八面钻新刃型刀具,并利用超声振动钻削技术,进行了八面钻超声振动钻削钛合金出口毛刺形成的基础理论和试验研究。理论分析了普通钻削和超声振动钻削的出口毛刺形成过程以及超声振动钻削的出口毛刺降低机理,同时试验验证了超声振动钻削的出口毛刺降低效果。结果表明:相比于钛合金普通钻削,超声振动钻削极大地提高了钻头刀具的切削能力,分别降低了钻削力16%~20%、切削温度18%~21%和出口毛刺高度82%~89%,有效降低了装配过程的去毛刺困难和生产成本。

Formation Mechanism of Exit Burr in Ultrasonic Vibration Drilling Titanium Alloys (Ti6Al4V) Using 8-Facet Drill

The big exit burr would be formed after the common drilling (CD) process of titanium alloys (Ti6Al4V) using a traditional twist drill,which would lead to the difficulty in deburring operations and has a negative influence on assembly quality of fastener.In this paper,a novel tool of 8-facet drill was introduced and the ultrasonic vibration drilling (UVD) technology was employed so as to perform the basic theory and experiment study of exit burr formation in ultrasonic vibration drilling titanium alloys using 8-facet drill.The exit burr formation process of CD and UVD as well as the exit burr reduction mechanism of UVD were analyzed by theoretical method, meanwhile the exit burr reduction effects of UVD were verified by experimental method.The results indicate that compared with the CD of Ti6Al4V,in the UVD process,the cutting ability of drill bit tool is greatly enhanced.The thrust force,cutting temperature and exit burr height decrease by 16% to 20%,18% to 21% and 82% to 89% respectively,as well as the trouble and cost of deburring operations in assembly process will be effectively reduced.