钛合金旋转超声辅助钻削的出口毛刺

针对航空航天领域钛合金难加工材料采用普通麻花钻传统钻削过程中孔出口毛刺大、导致去毛刺困难及影响紧固件装配质量的问题,提出了一种基于新刃型刀具(八面钻)的钛合金旋转超声辅助钻削(RUAD)的新技术。分析了RUAD原理,采用文中所设计的RUAD主轴结合CA6140车床平台、测力系统、测温系统、高速摄影系统以及非接触激光测量系统进行了钛合金RUAD制孔试验和孔出口毛刺研究,对比普通钻削(CD)分析了RUAD降低孔出口毛刺的机理,并建立了基于八面钻的CD和RUAD的毛刺形成模型。试验结果表明:相比于CD,RUAD明显降低钻削力、孔出口最高切削温度和毛刺高度,分别降低了16.79%~20.2%,18.54%~21.68%和82.27%~89.18%,极大降低了钛合金孔出口去毛刺的困难和制造成本,提高了生产进度。

Exit burr in rotary ultrasonic-assisted drilling of titanium alloys

In aerospace industries,to solve the problem of big exit burr which leads to the difficulty in deburring operations and poor assembly quality of fastener after the traditional drilling process of the difficultto-cut materials like titanium alloys using a twist drill,the rotary ultrasonic-assisted drilling (RUAD) technology of titanium alloys based on a novel tool (i.e.,8-facet drill) was proposed.The principles of RUAD process and motion trajectory of tool cutter tooth in RUAD were analyzed.And then,the drilling experiments were performed with a designed RUAD spindle unit,CA6140 lathe,measurement system of thrust force,measurement system of cutting temperature,high-speed video camera system and non-contact laser measurement system,and the type and size of exit burr were studied.In contrast to the common drilling (CD) of titanium alloys,the mechanisms of small or low burr height generated in RUAD were discussed and analyzed,and the theory models of burr formation mechanisms in CD and RUAD were obtained based on the high-speed camera images of burr formation and principle analysis of RUAD.The experimental results indicate that compared with CD,in RUAD process,the thrust force,maximum cutting temperature near the drilled hole exit and burr height of hole exit decrease by 16.79％-20.2％,18.54％-21.68％ and 82.27％-89.18％ respectively,which greatly reduces the troubles and manufacturing costs of deburring operations and improves the production process.