Mechanical properties and microstructural characteristics of 316L stainless steel fabricated by laser powder bed fusion and binder jetting

Abstract

In this work, the tensile test coupons and lattice structure of 316L stainless steel (SS) samples were manufactured by two powder bed-based additive manufacturing (AM) techniques-laser powder bed fusion (LPBF) and binder jetting (BJ) processes. The microstructure and mechanical properties of these components were investigated through a scanning electron microscope, hardness measurement, tensile tests, and compression tests. The results showed that the grain size of the LPBF sample was smaller than that of the BJ sample. This difference led to the microhardness of LPBF and BJ samples being 239.16 ± 4.90 HV and 208.71 ± 4.15 HV, respectively. The relative density of LPBF samples was 99.20 ± 0.30% and the BJ samples was 96.54 ± 0.54%. The LPBF samples had better mechanical properties, with tensile strength and compressive yield strength of 669.92 ± 18.68 MPa and 75.65 ± 5.77 MPa, respectively, while the tensile strength and compressive yield strength of the BJ samples were 437.55 ± 10.11 MPa and 78.65 ± 3.57 MPa, respectively. The experimental data showed good consistency with the simulation results (error within 10%) in both the compression modulus and yield strength for the lattice structures. These findings look promising for the future design of lattice structures with high mechanical properties using LPBF and BJ techniques.

Keywords

• Laser powder bed fusion
• Binder jetting
• Lattice structure
• Mechanical properties
• Microstructure