炭化ケイ素ウイスカー強化結晶化ガラス複合材料の機械的性質 (第2報)

ウイスカー径及びウイスカーへのカーボン被覆の影響

抄録

The effects of whisker diameter and carbon-coating to whisker on the mechanical properties of 20vol% SiC whisker-reinforced diopside and cordierite glass ceramic composites were studied. The flexural strength of the diopside reinforced with the whisker of 0.5μm diameter was 385MPa and that with the whisker of 1.1μm diameter was 355MPa. The flexural strengths of the diopside reinforced with the carbon-coated whisker were 358MPa for 0.5μm diameter and 334MPa for 1.2μm diameter. On the other hand, the flexural strength of the cordierite glass ceramic composite reinforced with carbon-coated whisker was almost the same as that reinforced with the noncoated whisker. The fracture toughness of diopside glass ceramic composites was increased with increasing whisker diameter and by coating whiskers with carbon. On the other hand, the fracture toughness of the cordierite glass ceramic composites was little affected by increasing whisker diameter nor by coating whiskers with carbon. It is concluded that the strengthening mechanism of the SiC whisker-reinforced glass ceramic composites is in load transfer phenomenon. While, it is confirmed that the toughening of the diopside glass ceramic composites is mainly due to whisker pullout, crack deflection and load transfer to whisker, and that of the cordierite glass ceramic composites is due to load transfer to whisker.