Effect of Hipping Pressure on The Grain Growth in Some Oxides

抄録

The grain growth under hipping pressure was investigated on some oxides; Ba(Ti_0.85Zr_0.15 )O₃(BZT), TiO₂ , MgAl₂O₄, MgO and Al₂O₃. The grain growth in BZT and TiO₂ was suppressed by hipping pressure. The hipping pressure increased the growth rate of grains in MgO, Al₂O₃ and MgAl₂O₄. The results were discussed based on the equation of grain growth; D=Kt^1/n.(D: grain size, K: constant, t: time, n: grain growth exponent). The n values were distributed over the wide range of 1 to 9, which depended on temperature and pressure. Particularly, the suppression of grain growth revealed large n value. Simple model was constructed to solve this problem, considering a coagulation model. It was concluded that the hipping pressure stabilized the grain boundary to decrease the growth rate of grains.