Compositional homogeneity in a medical-grade stainless steel sintered with a Mn-Si additive

In this paper, chemical composition uniformity in amorphous/nanocrystallization medical-grade stainless steel (ASTM ID: F2581) sintered with a Mn-Si additive was studied via scanning electron microscopy, energy dispersive X-ray spectroscopy, and transmission electron microscopy. The results show that as a result of sintering at 1000 degrees C, no dissociation of Mn-Si additive particles embedded in the stainless steel matrix occurs. In contrast, sintering at 1050 degrees C develops a relatively homogeneous microstructure from the chemical composition viewpoint. The aforementioned phenomena are explained by liquation of the Mn-Si eutectic additive, thereby wetting of the main powder particles, penetrating into the particle contacts and pore zones via capillary forces, and providing a path of high diffusivity. (C) 2012 Elsevier B.V. All rights reserved.