Dilatometry of ball milled nickel nano powder during non-isothermal sintering

Abstract

This work attempts to evaluate the sintering mechanisms of ball milled nanocrystalline nickel during nonisothermal heating. Samples showed a sintered density of 91.2% (theoretical) and grain growth up to 414 nm at 1273K. The activation energies of 12.4, 32.0 and 51.6 kJ/mol were found for viscous flow, lattice diffusion and grain boundary diffusion mechanisms respectively. Sintering was found to be controlled by interface reactions involving surface and grain boundary diffusions.