工艺参数对铜基激光熔覆层组织及耐磨性的影响

The Effect of Processing Parameters on the Microstructures of Cu-Alloy Coatings and Their Friction Resistance by Laser Cladding

关键词:  Cu基合金  激光熔覆  表面涂层  摩擦磨损

Key words:  Cu alloy  laser cladding  surface coating  friction

摘要:

采用激光加工方法在45号钢基体上熔覆表面铜合金涂层,试验研究了激光加工工艺参数(激光功率、扫描速度)对熔覆层组织特点和耐摩擦磨损性能的影响规律。试验发现,激光功率较大或扫描速度较慢时熔覆层中出现了富铁相,其形态分为球状和枝晶状两种,球状富铁相一般出现在熔覆层中上部,枝晶状富铁相一般出现在熔覆层底部,富铁相中一般含有少量的铜和锡,有的富铁相冷却时转变为马氏体组织。富铁相对铜合金熔覆层与40Cr摩擦副摩擦磨损不利,但是对铜合金熔覆层与硬质合金摩擦副摩擦磨损有利。

Abstract:

The laser processing was applied to carry out laser cladding Cu alloy coatings on 45 steel substrate.The effect of processing parameters,such as laser power,laser scanning speed,on the microstructures and friction resistance of the coatings was researched.The iron rich phase was found to appear in the coatings when the laser power was higher or scanning speed was slower,it is divided into sphere and dendrite formation in morphology,the spherical iron rich phase is found near the upper of coating layer and the branch iron rich phase in the bottom.It includes a few of Cu and Sn,some of the iron rich phase tranformed into martensite while colling.It is harmful to friction resistance of Cu alloy coatings against the 40Cr friction wheel,but it is benefit to the coatings against the hard alloy friction wheel.