焼結材料の組織制御 -多孔質焼結体における結晶粒成長- Microstructural Control of Sintered Materials -Grain Growth in Porous Compacts-
The size distribution function for the steady-state grain growth in the presence of Zener-type restraint due to residual pares was derived and compared with the experiruental data. The calculation is based on the Hillert's hypothetical rate equation for the grain growth and the grain size distribution is calculated by classifying the grain growth rate into three regions : the first region where grain size is small compared to the critical size and the grains are shrinking, the second region where grain boundary movement is completety restrained by the residual pores and the grain growth rate is zero, and, the third region where grain size is large enough to grow at the expense of small grains. According to the present calculation, the increase of restraining force results in the displacement of the peak position of the grain size distribution towards the smaller size, as small as half of the critical grain size, and narrowing of the size distribution. Compared with the experimental data of carbonyl Ni and carbonyl Fe sintered compacts at various conditions, the predicted grain size distribution is in good agreement with the experimental data whose grain growth is restrained by residual pores intersected with grain boundaries.
粉体および粉末冶金 43(10), 1177-1182, 1996-10-15
Japan Society of Powder and Powder Metallurgy