激光沉积制造扫描起点对T型梁热分布及成形质量的影响

Influence of Scanning Starting Point of Laser Deposition Manufacturing on Heat Distribution and Forming Quality of T-beam

为研究扫描起点对T型梁热分布及成形质量的影响,建立了T型梁的有限元模型,对激光沉积制造过程进行温度场模拟;通过红外热像仪对温度场模型进行了实验验证,对比了不同扫描起点下的温度场、层面节点温度及节点热循环的变化。数值模拟结果表明,扫描起点对温度场有很大影响,异侧扫描时层面热量分布较为均匀,横纵交叉处的节点温度下降较小。采用不同扫描起点进行了激光沉积实验。结果表明,由于扫描起点影响制件层面的热分布,进而影响制件的成形质量,异侧扫描时热量分布较为均匀,使得层面熔池宽度波动较小。

In order to study the influence of scanning starting point on the heat distribution and forming quality of T-beam,the finite element model of T-beam was established to simulate the temperature field of laser deposition manufacturing process.The temperature field model was verified by infrared camera.The change of temperature field,layer temperature and thermal cycle of nodes at different scanning starting points were compared.The numerical simulation results show that the scanning starting point has a great influence on the temperature field.The heat distribution of the layer is more uniform when the scanning points are located at opposite side,and the temperature drop of node at horizontal and vertical intersection is smaller.Two different scanning starting points were used in laser deposition manufacturing.The results show that the forming quality of the deposited part is influenced by the heat distribution of the layer because of different scanning starting point.The width fluctuation of molten pool is smaller,and the forming surface is smoother when the scanning points are located at opposite side,because the heat distribution is more uniform.