结构参数对选区激光熔化成形AlSi10Mg金刚石点阵结构拉伸性能的影响

Influence of Structural Parameters on Tensile Properties of AlSi10Mg Diamond Lattice Structures Prepared by Selective Laser Melting

选区激光熔化制备金属点阵结构由于具有结构设计自由度大、成形零件具有轻量化、缓冲吸震、隔热散热等优势在航空航天等领域具有广泛的工程应用前景。随着应用的不断拓展,对点阵结构的拉伸性能也提出了要求。通过有限元模拟,研究了金刚石单元结构参数对Al Si10Mg点阵结构拉伸性能的影响,并进行了试验验证。结果表明:所设计的点阵结构成形效果较好,具有稳定的力学性能;支杆杆径和孔隙率对点阵结构抗拉强度存在显著影响;随着支杆长径比的减小,点阵结构应力集中区域由节点处向支杆中间位置移动,长径比在1.4左右时点阵结构具有较为均匀的应力分布;在点阵结构外层包裹薄壳结构,可使点阵结构整体应力分布更为均匀。试验与仿真结果相吻合,可通过有限元方法对点阵结构的拉伸性能和变形失效方式进行有效预测。

Because of the advantages of large degree of freedom in structure design,light weight,cushioning,shock absorption,heat insulation and heat dissipation,the metal lattice structures formed by selective laser melting has a broad prospect in engineering application in aerospace and other fields.With the development of applications,the tensile properties of lattice structures are required.Through finite element simulation,the influence of diamond unit structure parameters on the tensile properties of AlSi10Mg lattice structures was studied and verified by experiments.The results show that the lattice structures has good forming effect and stable mechanical properties.The strut diameter and porosity have significant influence on the tensile strength of lattice structures.With the decrease of ratio of length to diameter,the stress concentration area of lattice structures moves from the node to the middle position of strut.When the ratio of length to diameter is about 1.4,the stress distribution of lattice structures is relatively uniform.The stress distribution of lattice structures can be more even if the lattice structures is covered with thin shell.The experimental results are in agreement with the simulation results,and the tensile properties and deformation failure modes of lattice structures can be predicted effectively by finite element method.