Impact of Different Heat Treatments on the Mechanical Properties and Microstructure of Precipitation-Hardened Stainless Steel Fabricated by Laser Powder Bed Fusion

Abstract

The mechanical properties of additively manufactured metal parts are often considered inferior to those of their traditionally manufactured counterparts. These inferior mechanical properties are primarily attributed to prevalent defects inherent in additive manufacturing processes, leading to reduced performance and durability. Researchers have extensively studied processing parameters and post-processing techniques to determine optimal conditions for improving the mechanical properties of laser powder bed fusion. This study investigates the densification and microstructure characteristics of laser powder bed fusion 15-5 precipitation-hardened stainless steel. The effects of three developed post-heat treatments and three build directions are examined. The results reveal that heat treatment schedules influence material strength and hardness at the cost of reduced ductility, while the fabrication build direction impacts surface porosity. Prolonged heat treatment procedures resulted in the highest hardness values due to enhanced homogenization.