连续/脉冲激光再制造温度场有限元分析与试验验证

Finite Element Analysis and Test Verification for Thermal Field of CW/Pulsed Laser Remanufacture

摘要:

以减少成形过程热输入,控制热影响区分布及成形层应力分布状态为目标,通过“生死单元”的有限元分析方法动态模拟激光再制造成形过程,对比分析连续/脉冲模式激光再制造温度场,采用非接触式红外测温仪验证分析结论,并就连续和脉冲工艺进行再制造成形进行对比试验验证。分析和试验结果表明：脉冲模式优化工艺参数为激光功率1.2Kw,光斑直径3mm,扫描速度5mm/s,单道成形层宽度3.2mm,脉冲激光脉宽10ms,占空比1:1；相同成形工艺和散热条件下,连续输出模式下多层成形层熔池温度最大值约为1400℃,较脉冲模式约高出170℃,且具有更大的热输入及热影响区范围,相关工艺及方法为叶轮叶片激光再制造提供分析和借鉴。

Abstract:

Aiming at reducing the heat input of the forming course, controlling the distribution of heat-affected zone and the stress distribution of the forming layers, the forming course of laser remanufacture was simulated dynamically in the method of finite element analysis. The temperature field of the laser remanufacture for CW/pulsed laser was compared and analysed, the non-contacting infrared thermometer was taken to validate the result of the analysis. The related CW/pulsed laser process was compared and validate by the experiment of laser remanufacture forming. The result of the analysis and the test shows that, the optimized process parameters of laser remanufacture for pulsed laser are the 1.2kW laser power, the 3mm spot diameter, the 5mm/s scanning speed, the 3.2mm width of the forming layer, the 10ms pulse width, the 1:1 duty ratio. On the same condition of forming and heat dissipation, the temperature maximum of laser remanufacture molten pool is about 1400℃,it is 170 ℃ higher than the pulsed laser. The heat input and heat-affected zone for CW laser remanufacture is bigger than the pulsed laser remanufacture’s. The related process and methods could be taken for reference for the remanufacture of impeller blades.