选区激光熔化成形AlMgScZr合金组织及性能研究

采用选区激光熔化（SLM）对AlMgScZr合金进行了打印成形，分析了不同激光功率对打印试样致密度、表面形貌、微观组织及力学性能的影响规律。结果表明，激光功率在80~240 W内，AlMgScZr合金的致密度先升后降，当激光功率为200 W时致密度达到最大值，为99.6%；AlMgScZr合金的抗拉强度与致密度密切相关，在近似全致密的状态下，合金的力学性能达到最优，抗拉强度和延伸率分别为492 MPa和18.4%；由于Sc、Zr元素的加入，合金内部形成与基体共格的Al₃（Sc， Zr）相，可作为有效的形核质点促进晶粒细化，其强化机制主要为细晶强化和析出强化。

Study on Microstructure and Properties of AlMgScZr Alloy Fabricated by Selective Laser Melting

This article uses selective laser melting （SLM） to print and form AlMgScZr alloy， and analyzes the influence of different laser powers on the density， surface morphology， microstructure， and mechanical properties of printed samples. In the range of laser power from 80W to 240W， the packed density of AlMgScZr alloy first increases and then decreases， reaching its maximum value at a laser power of 200W，with a maximum packed density of 99.6%.The tensile strength and packed density of AlMgScZr alloy are closely related.In a nearly fully compact state，the mechanical properties of the alloy reach their optimal level， with tensile strength and elongation of 492 MPa and 18.4%，respectively. Due to the addition of Sc and Zr elements，a Al₃（Sc，Zr） phase is formed inside the alloy coherent with the matrix.Al₃（Sc，Zr） phase can serve as an effective nucleation particle to promote grain refinement， and its strengthening mechanism mainly includes fine grain strengthening and precipitation strengthening.