选区激光熔化铝合金的组织和性能各向异性研究

Study on Microstructure and Mechanical Properties Anisotropyof Aluminium Alloy Prepared by Selective Laser Melting

基于Al-4.8Mn-1.7Mg-0.75Sc-0.75Zr铝合金,研究了各向异性对合金显微组织及力学性能的影响。结果表明,选区激光熔化制备出无裂纹致密合金样品,纵截面显微组织有典型熔池结构,由细等轴晶粒和长柱状晶组成,横截面显微组织有条带状结构,由细等轴晶组成。经时效处理后,横向试样屈服强度、抗拉强度和伸长率分别是512 MPa、540 MPa和15%,而纵向试样的屈服强度、抗拉强度和伸长率分别是502 MPa、536 MPa和12%,力学性能各向异性不显著。

The effects of anisotropy on microstructure and mechanical properties of Al-4.8Mn-1.7Mg-0.75Sc-0.75Zr alloy were studied.The results showed that crack-free dense samples were prepared by SLM.The microstructure of longitudinal samples is typical of a melt pool,withfine equiaxed grains and long columnar grains.The microstructure of transverse samples is strip-shaped and formed of tiny equiaxed grains.After aging treatment at 300℃for 5 h,the yield strength,tensile strength,and elongation of transverse samples are 512 MPa,540 MPa,and 15%,respectively,whereas the yield strength,tensile strength,and elongation of longitudinal samples are 502 MPa,536 MPa,and 12%,respectively.Mechanical property anisotropy is insignificant.The research presented above will provide favorable references for the use of 3D printed high-strength aluminum in aerospace.