AlSi10Mg的激光选区熔化成形研究

Study on the Selective Laser Melting of AlSi10Mg

利用激光选区熔化(selective laser melting,SLM)成形技术对Al Si10Mg铸造铝合金的成形进行了工艺研究,获得了致密的成形,并对其沉积态和热处理态试样进行了静态拉伸性能测试和显微组织分析。结果表明:对于Al Si10Mg,其SLM沉积态的常温拉伸强度远高于铸件标准,延伸率与铸态相当;退火工艺对SLM试样的组织及力学性能有着重要的影响,随着退火温度的提高,试样微观组织发生改变,在300℃、2 h退火工艺下,原本均匀分布的颗粒状Si聚集长大为针状,使得试样的强度下降,延伸率升高。抗拉强度由沉积态的507~518 MPa下降到378~406 MPa,延伸率由沉积态的3.0%~3.5%增加到6.5%~9.5%。

The growing interest for a wide range of usable AI alloy parts with complex shape in indus- trial field makes selective laser melting （SLM） stand out as a new technology for rapid prototyping manu- facturing. The objective of this work is to investigate AlSi10Mg cast aluminum alloy manufacturing by SLM. The investigation involved the influence of process parameters on the relative density and the infiu- ence of heat treatment on the microstructure and mechanical properties. High density and performance were achieved. The results show that the tensile strength of the SLMed AlSi10Mg is much higher than that of press wrought AlSi10Mg, but the elongation is as almost same as that of the press wrought AlSi10Mg. The heat treatment has a significant effect on the mechanical properties and microstructure of SLMed AlSi10Mg parts. The mechanical properties changes with the annealing temperature. Compared with the mechanical properties without annealing process, the tensile strength decreases from 507-518 MPa to 378-406 MPa and the elongation increases from 3.0%-3.5% to 6.5%-9.0% when the annealing temperature is 300℃ and the holding time is 2 h because of the changes in the morphology and distribu- tion of the Si.