The effect of heating rate on the mechanical properties of spark plasma sintered (SPS) nanostructured Fe-1.5 w/o Mo powder was evaluated. 1.5 w/o Si02 nanoparticles were added to the metal powder by high-energy milling to stabilize the nanostructure by grain-boundary pinning. Increasing the heating rate from 100°C/min to 300°C/ min shifted densification to a higher temperature and increased the fraction of ultrafine grains. At the lower heating rate, the materials is brittle; in comparison, at the higher heating rate, the materials undergoes plastic deformation with low strain hardening and a tensile ductility ~10%. The higher fraction of ultrafine grains following SPS at the higher heating rate is attributed to enhanced local overheating caused by current flow through the conductive particles.
Effect of heating rate on spark plasma sintering of nanostructured Fe-Mo powders
Molinari, Alberto;Libardi, Stefano;Maines, Lorena;
2012-01-01
Abstract
The effect of heating rate on the mechanical properties of spark plasma sintered (SPS) nanostructured Fe-1.5 w/o Mo powder was evaluated. 1.5 w/o Si02 nanoparticles were added to the metal powder by high-energy milling to stabilize the nanostructure by grain-boundary pinning. Increasing the heating rate from 100°C/min to 300°C/ min shifted densification to a higher temperature and increased the fraction of ultrafine grains. At the lower heating rate, the materials is brittle; in comparison, at the higher heating rate, the materials undergoes plastic deformation with low strain hardening and a tensile ductility ~10%. The higher fraction of ultrafine grains following SPS at the higher heating rate is attributed to enhanced local overheating caused by current flow through the conductive particles.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione
