Confined Uniaxial Compression of Granular Stainless Steel 316

The quasi-static compaction response of granular stainless steel 316 was studied under triaxial loading conditions using a confined crucible experiment apparatus, specifically looking at effects of the particle size 127 um, 309 um, 487 um on mechanical behavior. The material response was captured using load washer and strain gauges to relate: the porosity effects as a function of hydro-static pressure, particle size dependency on wall friction effects, and particle size-dependent failure mechanism. Our observations revealed that the path of crushing out porosity varied based on the particle size and the frictional effects. Scanning Electron Microscope (SEM) images were taken to observe the surface features of the compacted material and comment on failure mechanisms. Using these techniques it was observed that the smaller particles exhibited significant plastic deformation and flow, while the larger appeared to show micro cracking which lead to inelastic deformation and particle fracture. Altogether, these results are important because granular behavior is critical in powder flow applications such as additive manufacturing.