粉末材料性能对SLM模型制造过程影响的研究

Effect of Properties of Powders on Manufacturing Process(SLM) of Metallic Models

区域选择激光熔化(SLM)技术是金属模型和零件直接制造方法之一。采用相同激光参数加工不锈钢、工具钢、钛合金、铝合金等金属粉末时,铝合金粉末发生成球结晶现象,而其他金属粉末则形成致密的冶金结合。在模型加工过程中,铝合金粉末表现出铺粉性能差,制成的模型表面质量差等现象。由于不同的金属粉末具有不同的对激光的吸收能力、热传导、比热容、比重等性能,造成了上述加工过程和加工质量的不同。文章分析了具体原因,并采用简化的有限元计算证明了不同材料的热物理性能对这一激光加工过程的影响。

Selective Laser Melting （SLM） process is one of the methods of direct manufacturing for metallic models and parts. Metallic powder such as stainless steel, tool steel, titanium and aluminium alloys were radiated using Selective Laser Melting process. In the process bailing occurred by aluminium alloys, metallurgical bond formed by other alloys. In the model manufacturing aluminium alloys appeared to be difficult to be distributed on the powder bed and different model quality. It resulted from different properties such as lower absorption to laser beam, higher thermal conduction, density, special thermal capability and so on. The paper analysed the reason and proved the effect of different thermal physical properties of different kinds of metal powder on manufacturing process by FEM-Calculation simplified.