Kinetic analysis of the Ni-activated W-sintering by dilatometry of heating-up stage

The analysis of the initial stage sintering, i.e., the sintering processed during the heating-up stage, is very important for understanding of sintering kinetics of any sintering system, especially, for the case of the activated sintering, by which the relatively high sintering shrinkage in the early stage of sintering is due to the enhanced sinterability. In the present study the simple analytical method of dilatometric data during heating up stage was developed, and applied for the analysis of W activated sintering. The sintering kinetic of the non doped W-powder compact is explained by grain boundary diffusion mechanism with the activation energy of 262.3kJ/mol, while that of Ni-doped W powder compact was controlled by volume diffusion mechanism with the activation energy of 240.5kJ/mol.