【摘要】 为了分析Co基合金熔覆过程的应力场,建立了激光熔覆预置Co基合金粉末过程的三维模型,考虑温度变化对热物理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软件分析了激光熔覆过程中的应力场,并进行了试验验证。结果表明:通过比较分析扫描速度为5 mm/s的涂层获得良好的冶金结合;工件残余应力均为拉应力,且最大值出现在z向距表面约2 mm处,最大变形量出现在工件的边缘位置;随扫描速度的增加,工件的残余应力和变形均明显减小,这说明在其它工艺参数一定的前提下,适当降低扫描速度,能有效减小熔覆层的应力集中,获得质量优异的涂层。模拟结果为激光熔覆过程的工业化提供了理论依据。更多还原

【Abstract】 In order to analyze stress field of Co-based alloys laser cladding,a three-dimensional( 3D)physical model of Co-based alloys laser cladding with preset-powder method has been made on low carbon steel substrate by finite element method,and the thermo-physical properties established as the functions of temperature,the surface convective heat transfer,and the radiant heat transfer were taken into consideration. The stress field of laser cladding process was analyzed by SYSWELD software. A 5 kW CO2laser was used to prepare Co-based alloy coatings on low carbon steel substrate. Dilution rate of the coating were examined. The results showed that favorable metallurgy bonding of coatings with scanning velocity of 5 mm / s was obtained by comparison and analysis. Residual stress of work-piece was all tensile stress,and the maximum appeared at the distance of 2 mm from the surface in the z direction,and the residual distortion and stress of work-piece were all obviously decreased with lower scanning speed. With the same other process parameters,stress concentration of coatings was effectively reduced by the proper scanning speed,and quality excellent coatings could be obtained. The simulated result provided the theoretical basis for the industrialization of the laser cladding.更多还原