铜基体上激光熔覆钴基合金的数值模拟

Numerical Simulation of Laser Cladding Co-based Alloy on the Surface of Copper

以黄铜为基材,钴基合金为熔覆粉末,采用预置粉末方式实现激光熔覆加工,对此过程建立三维有限元模型。考虑温度变化对热物性参数的影响以及表面对流换热和辐射散热等影响因素,使用SYSWELD软件对激光熔覆过程中的温度场和应力场进行了分析。结果表明,激光熔覆过程中的温度场变化是由非稳态到稳态的过程,熔覆层横截面上不同点热循环曲线呈锯齿状衰减;最大残余应力值出现在靠近基体的熔覆层中间位置;在其他工艺参数不变的情况下,扫描速度为8mm/s,熔覆过程的稀释率为11.5%,可以获得良好的冶金结合,并进行了试验验证;利用SYSWELD软件的校核功能,获得了扫描速度为6和10mm/s熔覆过程中较为合适的功率分别为2.96和3.82kW。

Laser cladding Co-based alloy on surface of the brass was carried out by pre-deposited method.A three-dimensional finite element model for temperature was established,where the effects of temperature on thermo-physical parameters and surface convective heat transfer as well as radiant heat transfer were taken into account.The temperature field and stress field of laser cladding Co/Cu alloy were analyzed by the SYSWELD software.The results show that temperature field exhibits the tendency of non-steady state to steady state during the laser cladding process,and peak temperature of different points was reduced with serrated tendency at cross section of the cladding surface,and maximum residual stress can be observed in the middle layer of cladding surface nearby the matrix alloy.The desirable metallurgical boding with 11.5% dilution can be realized by scanning speed at 8 mm/s with the same other parameters,which is validated by the experiment.The acceptable powers of 2.96kW and 3.82kW are presented with scanning velocity of 6 mm/s and 10 mm/s by SYSWELD check.The results provide a reference for parameter optimization and control of dilution rate of laser cladding layer.