Effect of manufacturing parameters on the microstructure and mechanical properties of metal laser sintering parts of precipitate hardenable metals

Abstract

Additive manufacturing (AM) started as a rapid prototyping (RP) technology to aid in visualizing and validating designs in the design process. However, with the recent improvements in metal AM parts, functional parts can be manufactured using laser-based AM. Currently, metal AM parts have comparable mechanical properties to traditional manufacturing parts. 15-5PH stainless steel and Inconel 718 are two of the most commonly used metals in laser-based AM, and they have a high modulus of elasticity and tensile strength and can be precipitate hardened to increase their strength and hardness by heat treatment. These properties make 15-5PH stainless steel and Inconel 718 suitable for many industrial applications such as aerospace and automotive. However, due to the nature of AM, AM parts usually suffer from anisotropy. In this paper, the mechanical properties such as tensile strength, modulus of elasticity, yield strength, and ductility are investigated at various elevated temperatures up to 350 °C and compared with the mechanical properties at room temperature using specimens printed in three different orientations to capture the effect on the anisotropy. In addition to that, the microstructure of the specimens is studied to investigate the influence of elevated temperature on the specimens.