TIG增材成形5356铝合金温度场数值模拟分析

用Abaqus软件结合单元生死法,建立钨极惰性气体(tungsten inert gas,TIG)增材成形5356铝合金有限元模型,探讨层间冷却时间、增材方向及预热对温度场的影响规律,并通过实测温度验证仿真结果。结果表明:随层间冷却时间递增,第1层表面中点温度循环曲线的峰值与谷值下降;随层数增加,峰值温度先快速下降,后缓慢下降;谷值温度先快速增加,后缓慢增加。往复式增材成形可有效改善同向增材在熄弧端因热量积累导致的成形缺陷,有利于提升表面平整度。在合理温度范围内的基板预热可使温度分布更均匀。

Numerical simulation analysis of temperature field of 5356 aluminum alloy based on TIG arc additive manufacturing

Abaqus software combined element birth and death method was used to establish a finite element model of 5356 aluminum alloy for additive manufacturing of tungsten inert gas(TIG).The effects of interlayer cooling time,surfacing direction and preheating on temperature field were discussed.The simulation results were verified by the measured temperature.The results show that as the interlayer cooling time increases,the peak and trough values of the thermal cycling curve at the midpoint of the first layer surface decrease.As the number of layers increases,the peak temperature first rapidly decreases and then slowly decreases,while the temperature of the trough first increases rapidly and then increases gradually.Reciprocating surfacing can effectively improve the forming defects caused by the accumulation of the heat at the arc extinguishing end of the same direction,which is beneficial to improve surface flatness.Preheating substrate within a reasonable temperature range can make the temperature distribution of substrate more uniform.