进给距离对激光-电复合熔覆层组织及性能的影响

Effect of feed distance on microstructure and properties of laser-electric composite cladding layer

本文采用“激光-电复合丝材熔覆”的方法对机械零件进行修复工艺研究。采用630不锈钢丝材在45#钢表面进行多道单层熔覆实验,研究不同进给距离对熔覆层宏观形貌、微观组织、显微硬度和耐磨损性能的影响。结果表明:随着进给距离的增加,熔覆层与基体结合面变的凹凸不平,熔覆层表面均有杂质小颗粒,熔覆层厚度减小,微观组织为混乱的等轴晶,熔覆层的平均硬度在200 HV上下浮动,摩擦系数呈现先降低后上升的趋势,磨损量与摩擦系数呈现正相关关系,观察其磨痕形貌其磨损形式主要为疲劳磨损和黏着磨损,当前实验条件下进给距离为1.2 mm时,耐磨性能最佳。

In this paper,the repair process of mechanical parts is studied by the method of"laser-electric composite wire cladding".Multi-pass single layer cladding experiments are conducted on 45#steel surface using 630 stainless steel wire to investigate the effects of different feed distances on the macroscopic morphology,microstructure,microhardness and wear resistance of the clad layer.The results show that with the increase of feeding distance,the bonding surface of the clad layer and the substrate became uneven,the surface of the clad layer has small particles of impurities,the thickness of the clad layer decreases,the microstructure is chaotic isometric crystal,the average hardness of the clad layer fluctuated above and below 200 HV.Moreover,the coefficient of friction shows a tendency of decreasing and then increasing,and there is a positive correlation between the amount of wear and the coefficient of friction.The wear patterns of the wear marks are observed and the wear forms are mainly fatigue wear and adhesive wear and the best wear resistance is achieved when the feed distance is 1.2 mm under the current experimental conditions.