切削用量对铍材加工表面变质层的影响及铍材切削变形方式

Effect of Cutting Parameter on Surface Modification Layer of Beryllium and Deformation Mode of Beryllium Cutting

通过单因素实验研究不同切削用量对铍材切削表面损伤层、加工硬化层的影响,并结合切屑、表面组织结构变化分析铍材切削过程的变形方式。结果表明:在一定范围内,铍材切削表面损伤层、硬化层厚度受切削速度影响较小,呈现随切削进给量、深度的增加而增大的趋势。铍材切削过程未发生剧烈的塑性变形,大量剪切滑移产生的加工硬化在局部达到材料破裂强度,进而使其发生脆性断裂,产生挤裂型切屑;铍材切削表面的孪晶数量很少,受后刀面挤压产生的位错运动是其主要的塑性变形方式。

Through single factor experiment,the effects of different cutting parameters on the damage layer and work hardening layer of beryllium cutting surface were studied,and the deformation mode of beryllium cutting process was analyzed in combination with the chip and surface microstructure changes.The results show that within a certain range,the thickness of the surface damage layer and hardening layer is less affected by cutting speed,and shows the trend of increasing with the increase of cutting feed and depth.Du-ring the cutting process of beryllium,there is no severe plastic deformation.The work hardening caused by a large amount of shear slip reaches the material fracture strength locally and then brittle fracture occurs to result in extrusion chip.A very small amount of twin crystal appears on beryllium cutting surface,and the dislocation movement generated by the extrusion of the flank face is the main mode of plastic deformation.