分区扫描对激光沉积修复钛合金热力耦合场的影响

Influence of separate area scanning on coupled thermo-mechanical field of laser repairing of titanium alloy

为了控制激光沉积修复过程中残余应力,减少基材的变形,利用ANSYS参数化设计编程语言实现了激光沉积修复面缺陷损伤零件热力耦合场的数值模拟,得到了短光栅连续扫描和分区扫描情况下的节点热循环特性、温度场和残余应力场分布规律.结果表明,不同扫描方式下节点的热循环分布规律相似,但分区扫描时基材热量累积明显减小,且温度分布较为均匀,从而改善了基材中应力集中,使残余应力降低.为了验证结果的正确性,采用红外测温仪和压痕应变仪对不同扫描方式下激光沉积修复温度场和修复件表面残余应力进行了测量,并绘制了基材变形曲线.二者具有较好的一致性.

In order to control the residual stress in the process of laser deposition repair and reduce the deformation of the substrate,a laser deposition parts thermal coupling field numerical simulation in the repair surface was established on the ANSYS parametric design programming language. Thermal cycle characteristics,distribution rule of temperature field and residualstress field was analyzed under sequential scan and subarea scan. The results showed that the thermal cycle of nodes was similar under different scanning patterns. And substrate heat accumulation decreased greatly by subarea scan,at the same time the temperature distribution is relatively uniform so as to improve the stress concentration in the substrate and reduce residual stress. In order to verify the result,laser deposition temperature field and residual stress were measured by infrared thermometer and indentation strain gauge,and the substrate material deformation curve was plotted. The results showed that numerical simulations was in good agreement with the experimental results.