SLM成形多层多道金属薄壁件温度场有限元模拟

针对高强铝合金A17075选区激光熔化（selective laser melting,SLM）过程中未知的熔池变化规律和层间作用影响产品成形效率和精度的问题,研究不同工艺参数（激光功率和扫描速度）对各成形层熔池形态和温度场的影响。利用有限元分析软件ANSYS建立金属薄壁件SLM成形的多层多道温度场有限元模型,同时,利用APDL（ansys parametric design language）语言编程模拟了激光热源的加载、激光功率与扫描速度,采用“单元生死”技术描述金属粉末材料的动态增长过程,得出瞬态温度场的分布状况。结果表明,激光功率与扫描速度各自影响不同的温度场因素,适合Al7075粉末的SLM工艺参数为功率250~300 W,速度800~1 000 mm/s。本文得到了激光功率和扫描速度的合理范围,为高强铝合金SLM实际实验提供理论参考。

Finite element simulation of temperature field of SLM forming

Aiming at the problem that the unknown variation rule of molten pool and the interlayer effect on the forming efficiency and precision of products in the process of selective laser melting(SLM) of high-strength aluminum alloy A17075, the influence of different process parameters (laser power and scanning speed) on the morphology of the molten pool and the temperature field of the various forming layers was investigated. The finite element analysis software ANSYS was used to establish a multi-layer and multi-channel temperature field finite element model for SLM forming of thin-walled metal parts, and at the same time, the loading of the laser heat source, the laser power and the scanning speed were simulated by using the programming of the language APDL (ansys parametric design language), and the DK]"element birth and death" technique was adopted to describe the dynamic growth process of the metal powder material and the distribution of the transient temperature field was derived. The results show that the laser power and scanning speed affect different temperature field factors, and the SLM process parameters suitable for Al7075 powder are power of 250~300 W and speed of 800~1 000 mm/s. The reasonable range of leser power and scanning speed is obtained, which provides theoretical reference and support for high-strength aluminum alloy in SLM practical experiments.