ABSTRACT

Tool–chip interface friction significantly affects the machining characteristics like cutting forces, machining temperature, tool wear, and surface finish. Structuring the tool rake face using micro-textures is a recent method adopted to reduce tool–chip interface friction. The effect of varying the depth of these rake face micro-textures on the machinability of AISI4340 is studied. Textures of uniform width but with depth varying from 60 to 145 μm are created on the tool rake face using wire-EDM process perpendicular to the chip flow direction. The performance of these tools is compared with a non-textured tool in terms of cutting forces, cutting zone temperature, flank wear, chip trace area and surface finish. It is found that by optimizing the texture depth, it is possible to get improved performance from the cutting tool for the same machining conditions as compared to a non-textured tool. Further, it is found that for all the tools, the chip morphology changes during each pass from regular, closely curled helix at the beginning of the pass to randomly coiled chips at the end of the pass length with simultaneous increase in temperature.

摘要

刀具-切屑界面摩擦显着影响切削力、加工温度、刀具磨损和表面光洁度等加工特性。使用微纹理构造刀具前刀面是最近用于减少刀具-切屑界面摩擦的一种方法。研究了改变这些前刀面微纹理的深度对 AISI4340 可加工性的影响。使用垂直于切屑流动方向的电火花线切割工艺在刀具前刀面上创建宽度均匀但深度从 60 到 145 μm 不等的纹理。在切削力、切削区温度、后刀面磨损、切屑痕迹面积和表面光洁度方面，将这些刀具的性能与无纹理刀具进行比较。发现通过优化纹理深度，与无纹理刀具相比，在相同的加工条件下，切削刀具可以获得更高的性能。此外，还发现对于所有刀具，切屑形态在每次加工过程中都会发生变化，从加工开始时的规则、紧密卷曲的螺旋线到加工长度末端的随机盘绕切屑，同时温度升高。