SLM成形AlSi10Mg合金的组织与力学性能

Microstructure and Mechanical Properties of AlSi10Mg Alloy Fabricated by SLM Technology

摘要: 在激光功率450 W、扫描速度3800 mm/s、扫描间距60 μm、层厚30 μm条件下，SLM成形了AlSi10Mg试样，用XRD、OM和SEM分析了其相组成与微观组织，并测试了室温硬度和拉伸力学性能。结果表明，试样组织主要由Al基体、Si相和少量的Mg2Si相组成。横截面主要由大小均匀“带状”条纹构成，条纹中可分为三个区域：内部细晶区、热影响区、边界粗晶区；纵截面由大小不均的“U形”条纹构成，条纹间界限明显，条纹中分为两个区域：内部等轴晶区、边界柱状晶区。该参数下得到的试样综合力学性能优异，抗拉强度、屈服强度和伸长率分别达到470 MPa、327 MPa和8.0%。

Abstract: AlSi10Mg samples were fabricated by SLM technology under the process parameters where laser power, scanning speed, scanning interval and layer thickness were 450 W, 3800 mm/s, 60 μm and 30 μm, respectively. Phase composition and microstructure were analyzed by XRD, OM and SEM, and meanwhile the hardness and tensile mechanical properties at ambient temperature were studied. The results show that the microstructure mainly consists of Al matrix, Si phase and a little Mg2Si phase. Microstructure of cross section mainly consists of uniform “band” strips. The stripe can be divided into inner fine crystal zone, heat affected zone and boundary coarse grain zone. Microstructure of longitudinal section mainly consists of uniform “U-shaped” stripes. The bounda-ries between the stripes are clear; meanwhile the stripes are divided into inner equiaxed crystal zone and boundary columnar crystal zone. The sample obtained under this parameter exhibits excellent comprehensive mechanical properties, where the tensile strength, yield strength and elongation reach 470 MPa, 327 MPa and 8.0%, respectively.