钢表面激光熔覆镍基合金涂层裂纹控制的研究

Study on Control of Crack in Laser Cladding Ni-based Coating on Steel

在对45钢表面激光熔覆镍基合金涂层组织、相分析的基础上,对熔覆层裂纹的形成机理进行了研究,热应力、硼化物的偏聚和熔覆层中的夹渣是导致熔覆裂纹产生的主要原因。为了消除裂纹,采用超声振动激光熔覆的方法,制备了超声振动激光熔覆Ni60B涂层和超声振动激光熔覆Ni60B+1%Y2O3涂层,并对它们的显微组织和裂纹情况进行了分析。结果表明,超声振动对镍基合金熔覆层裂纹有很好的抑制作用,通过添加适量的稀土元素,制备了成形良好无裂纹的涂层。

The crack formation mechanism was studied on the basis of analyzing the results of the microstructure and phase composition of laser cladding Ni60B alloy on 45 steel.Thermal stress,segregation of boride and slag in the cladding layer are the main reasons for resulting in cracks.To eliminate the cracks in the coating,ultrasonic vibration laser cladding was carried out to produce Ni60B layer and Ni60B＋1%Y2O3 layer,meanwhile,the microstructure and crack behavior were analyzed.The results show that the ultrasonic vibration has a good depression on cladding crack.Well formed and crack-free laser cladding coating is produced by adding a bit of rare-earth element.