MgO-SiCウイスカー複合セラミックスの破壊エネルギ
1987 年 36 巻 400 号 p. 17-21
詳細
1987 年 36 巻 400 号 p. 17-21
In order to develop MgO base ceramics having higher thermal shock resistance for MHD plant use, ceramic composites of MgO reinforced with 15 and 20wt% of SiC whisker were fabricated by the hot-pressing at 1800°C and 1900°C under 200kg/cm2 for 30min. The effective fracture energy (γeff) of the hot-pressed composites and MgO were measured by work of fracture technique using chevron notched specimens over the range from room temperature to 1400°C. Up to 1000°C, the γeff values of the composite ceramics were slightly lager than those of the hot-pressed MgO. At temperatures above 1000°C, the γeff values of the composites increased remarkably, and were about 3-7times higher than those of hot-pressed MgO at 1400°C.
The mechanism of the increase in γeff values were discussed on the basis of the load-deflection behavior in bending fracture, the chemical reaction of SiC whisker with MgO matrix and the fracture surface morphology.
