单胞构型和结构参数对SLM成形梯度点阵结构压缩性能的影响

梯度点阵结构由于压缩时具有优秀的吸能能力,目前常作为吸能组件被应用于航天、国防和医疗等领域。但随着现代工业的发展,工程领域对其压缩性能提出了更高的要求,为使其进一步优化,有必要探讨单胞构型、结构参数和压缩性能之间的关系。因此本研究通过选区激光熔化(Selective laser melting, SLM)成形了两种梯度差的AlSi10Mg变杆径梯度体心立方(Body-centered cubic, BCC)和金刚石(Diamond, Diam)结构,以研究梯度差对压缩性能的影响,并对两种单胞构型进行对比。准静态单轴压缩实验和有限元分析(Finite element analysis, FEA)的结果表明,在同相对密度下,当单胞构型相同时,随着梯度差的增加单位体积吸能量明显增加。而梯度差相同时,Diam梯度点阵结构的压缩模量、屈服强度、抗压强度和最大峰值应力均高于BCC,同时其单位体积吸能量和吸能效率也高于BCC。

Effect of Cell and Structural Parameter on Compression Properties of Gradient Lattice Structures Manufactured by SLM

Gradient lattice structure is now commonly used as energy-absorbing components in aerospace, national defense and medical fields due to its excellent energy absorption ability when compressed. However, with the development of modern industry, the engineering field has put forward higher requirements on its compression properties. To make it further optimized, it is necessary to study the relationship between cell, structural parameters and compression properties. Therefore, in this study, two AlSi10Mg rod-diameter-change gradient body-centered cubic (BCC) and diamond (Diam) structures with different gradient gap were formed by selective laser melting (SLM) to investigate the effect of gradient gap on the compression properties, and to compare the two cells. The results of quasi-static uniaxial compression experiments and finite element analysis (FEA) show that the absorbed energy per unit volume increases significantly with the increase of gradient gap at the same relative density and with the same cell. The compressive modulus, yield strength, compressive strength and peak stress of Diam gradient lattice structure are higher than those of BCC when the gradient gap is the same, and its absorbed energy per unit volume and energy absorption efficiency are also higher than those of BCC.