Effect of heat treatment on compression properties of the 316L diamond structure fabricated through selective laser melting

Abstract

Designing a triply periodic minimal surface (TPMS) lattice structure is a new method for lightweight. Compared with the previous foam- and strut-based structure, the TPMS lattice structure has the advantages of precise control of mechanical properties and convenient modelling. In this paper, under a quasi-static compression load, the effect of solution and aging treatment on the mechanical properties and energy absorption capacity of graded skeleton diamond (GSKD), graded sheet diamond (GSHD), uniform skeleton diamond (USKD) and uniform sheet diamond (USHD) fabricated through selective laser melting (SLM) were studied. The experiment results show that the sheet structures have better mechanical properties (elastic modulus, yield strength, platform stress and energy absorption) than the skeleton structures, and that the uniform structures have a higher energy absorption capacity (WV, εd) than the gradient structures, with the WV,εd of the as-built USHD sample reaching 2.11 times that of the GSKD sample. Moreover, the mechanical properties of each structure have different degrees of sensitivity to heat treatment conditions. Heat treatment has the greatest influence on the platform stress and initial strain of densification of GSKD, on the Young's modulus of USHD and on the energy absorption of USKD.