激光渗氮强化数控机床传动轴的组织与性能调控研究

Microstructure and Performance Regulation of Transmission Shaft of NC Machine Tool Strengthened by Laser Nitriding

采用连续光纤激光器研究了12组(A~L组)不同激光参数对数控机床传动轴的表面氮化效果,从中选出了3组最佳参数研究了其渗氮后的组织与性能,以期为揭示表层氮化后的显微组织结构成分及其物理-机械行为等演变规律奠定基础。结果表明,当激光功率为1.2 kW、扫描速度为3 mm·s^(-1)时形成的渗氮层表面粗糙度最低,为Ra 1.6μm;显微组织不仅得到细化,也从回火索氏体变为由马氏体、碳化物、氮化物和基体组织组成的混合组织。此外,渗氮层的显微硬度、抗磨损性能以及抗拉强度均得到了相应的提高。

In this paper, a continuous fiber laser was used to study the surface nitriding effect on CNC machine drive shaft by 12 groups(Group A~L) of different laser parameters. Three groups of optimum parameters were selected to study the microstructure and properties after laser nitriding, in order to lay a foundation for revealing the evolution law of microstructure, composition, and physical mechanical behavior. The results show that when the laser power and scanning speed is 1.2 kW and 3 mm·s^(-1) respectively, the surface roughness of the nitrided layer is Ra=1.6 μm, which is the lowest compared with other parameters. The microstructure is not only refined, but also changed from tempered sorbite to a mixture of martensite, carbide, nitride, and matrix. In addition, the microhardness, wear resistance, and tensile strength of nitriding layer are improved accordingly.