Effect of powder particle size on the microscopic morphology and mechanical properties of 316 L stainless steel hollow spheres

316 L stainless steel powder with varying particle sizes was chosen as the raw material for the fabrication of metal hollow spheres using powder metallurgy techniques. The powder’s particle size, composition, and micro-morphology were examined, followed by porosity and capillary force calculations, compressive testing, and fracture analysis. The findings reveal significant disparities in the micro-morphology and mechanical properties among the metal powders with different particle sizes. Smaller particle sizes result in denser bonding of the hollow spheres, leading to higher compressive yield strength. Conversely, larger powder particle sizes substantially increase the porosity of the hollow sphere wall, resulting in a sharp decline in mechanical properties and a transition from ductile fracture to brittle fracture in its failure mode. This study’s innovation lies in its meticulous examination of the relationship between particle size distribution and the resulting microstructural and mechanical properties of 316 L stainless steel hollow spheres, providing valuable data that enhances the understanding of powder metallurgy processes and drives the development of advanced materials for aerospace applications.

Graphical Abstract