摘要
为了降低成形过程的热应力,根据有限元方法中的"单元生死"技术,利用APDL语言编程实现了对多道多层激光金属沉积成形过程三维温度场的数值模拟,再现了成形过程中温度场的动态变化,得到了成形过程中模型温度场及温度梯度的分布规律。结果表明,试样同一纵断面上各节点虽然被激活的时间不一样,但它们具有相似的温度变化规律;试样内的温度梯度主要沿z轴方向分布,基板内的温度梯度主要沿平行基板方向分布,具有明显的分层现象,熔池区的温度梯度非常大。在相同的工艺参数下,实际成形试样的扫描电镜照片与模拟结果吻合很好。
In order to decrease the thermal stress during process, based on the ＂element life and death＂ technique of finite element method （ FEM）, detailed numerical simulation of 3-D multi-track and multi-layer temperature field during laser metal deposition Shaping （LMDS） process was conducted with ANSYS parametric design language （ APDL）. Through those simulation, the dynamic variation of temperature in model reappeared, and the distribution rule of temperature and temperature gradient was obtained. The calculated results show that although the nodes on longitudinal section have different activated time, they have similar temperature variation history; the temperature gradients in sample are mainly along z direction, and the temperature gradients in substrate are mainly parallel to substrate. Under the same conditions, the SEM photos of samples tallies closely with the simulations results.
出处
《激光技术》
CAS
CSCD
北大核心
2007年第4期394-396,430,共4页
Laser Technology
关键词
激光技术
激光金属沉积成形
瞬态温度场
数值模拟
laser technique
laser metal deposition shaping
transient temperature field
numerical simulation
