ABSTRACT Residual stresses are induced mainly due to the plastic deformation or heat generation during metal cutting process. Mechanical stresses are themselves dependent on machining forces while thermal stresses depend on the magnitude of the produced heat during cutting process. Laser-assisted machining is a process in which a controlled laser source is used to increase the local temperature in some parts of a workpiece which are about to be cut. Therefore, the material resistance against the cutting will be reduced and machining process will lead to smaller values of cutting forces and temperatures which will finally decrease the induced residual stress in workpiece surface. In this paper, the impact of laser source parameters (power and spot size) and also machining parameters (cutting speed and feed) on surface residual stress in laser-assisted machining of AISI 4140 was experimentally studied. Based on the obtained results, by increasing laser source power, the machining-induced surface residual stresses in the selected range of machining parameters became more compressive; with an increase in Ps from 200 to 500 W, the average value of machining-induced surface residual stresses became more compressive by 48.47%.

中文翻译：

---

工艺参数对激光辅助加工残余应力的影响

摘要 残余应力主要是由于金属切削过程中的塑性变形或发热引起的。机械应力本身取决于加工力，而热应力取决于切削过程中产生的热量。激光辅助加工是一种过程，其中使用受控激光源来增加将要切割的工件某些部分的局部温度。因此，材料对切削的阻力会降低，加工过程会导致切削力和温度值变小，最终会降低工件表面的残余应力。在本文中，实验研究了激光源参数（功率和光斑尺寸）以及加工参数（切削速度和进给）对 AISI 4140 激光辅助加工中表面残余应力的影响。根据获得的结果，通过增加激光源功率，在选定的加工参数范围内，加工引起的表面残余应力变得更加压缩；随着 Ps 从 200 W 增加到 500 W，加工引起的表面残余应力的平均值变得更加压缩 48.47%。