高速ガス衝突急冷により熱衝撃をうけるセラミックスの信頼性評価

概要

論文の詳細を見る
Fracture strength of cylindrical specimens made of Si_3N_4 and SiC were evaluated by a thermal shock test. Each specimen was preheated uniformly at 1573 K in an electric furnace, then cooled locally by high-velocity helium gas passed through a narrow slit. The transient temperature distribution and the thermal stress were calculated by FE analysis. The failure probability was also estimated by assuming that the fracture strength due to thermal shock was determined by the fracture toughness of the material and the two-parameter Weibull distribution was able to apply the distribution of initial flaw size. Predicted failure probability of SiC was good agreement with test results. As for Si_3N_4, large difference was observed between the estimated and the tested failure probability. The descrepancy was however decreased in consideration of subcritical crack growth during thermal-shock tests.
社団法人日本機械学会の論文
2001-08-25