The Effect of the Deposition Strategy and Heat Treatment on Cold Spray Additive Manufactured 316L Stainless Steel

Herein, the effect of heat treatment on the characteristics and properties of cold spray additive manufactured 316L stainless steel employing traditional and a new metal knitting strategy is investigated. 316L feedstock powder characteristics, the geometry of the bulk, microstructure, porosity, microhardness, mechanical isotropy, and residual stress are analyzed in both strategies in as-sprayed and heat-treated conditions. Results show that the traditional deposition strategy produced higher mechanical resistance, whereas metal knitting presents a better part geometry accuracy. The heat treatment significantly improves the material strength and the quality of the parts by recovery and recrystallization phenomena. The same microhardness and planar isotropy are achieved after heat treatment of samples produced by both strategies. A discussion about the mechanisms, microstructural, and residual stress evolution is presented. Developing new cold spray additive manufacturing strategies to make metallic components improves the part geometry accuracy but negatively affects the material properties due to a lower cohesion of particles. Heat treatments solve this effect by increasing the strength and homogenizing the residual stresses.image (c) 2024 WILEY-VCH GmbH