不同材料去除模式下激光加热辅助切削氮化硅陶瓷表面粗糙度研究

激光加热辅助切削因其工艺空间大、经济性高、可得到高质量表面成为工程陶瓷等脆硬材料的高效加工方式。通过改变激光功率和切削深度两组单因素试验，研究了激光加热辅助切削氮化硅陶瓷（Si3N4）不同加工状态下表面粗糙度值的变化规律。结果表明:材料被塑性去除时，Ra和Rq值均小于被脆性去除和产生热损伤时得到的值。未产生热损伤时，Ra和Rq值随工件软化程度增大而减小。在塑性去除模式下，轮廓高度幅值曲线更加趋于对称和正态分布，表面轮廓更加精细。

Study on surface roughness in laser assisted machining of Si3N4 ceramics under different material removal modes

Laser assisted machining (LAM) is effective for machining brittle and hard materials such as engineering ceramics. Because it has larger technological space, is more economical, and can achieve a better surface integrity. In this paper, two sets of single factor experiments were performed in which the laser power and the cutting depth were changed respectively. The change of the surface roughness under different material removal modes for LAM of Si3N4 was studied using a variety of parameters. The results show that the values of Ra and Rq are smaller in the plastically machining state than that obtained when the material is removed through a brittle fracturing or thermal damage occurs. When there is no thermal damage, the value of Ra and Rq decrease with the increase of the softening degree of the workpiece. In the ductile material removal mode, the distribution of height amplitude curve of the surface tends to be more symmetrical and more normally; the surface contour is more fine.