| 摘要 |
PURPOSE:To obtain a ceramic part high in mechanical strength and improved in corrosion resistance, applicable to engine parts such as a hot plug as a constituent of a combustion chamber exposed to combustion gas. CONSTITUTION:This ceramic part for engines is made of a sintered compact consisting mainly of Si3N4 and having grain boundary phase consisting of Si- Al-Y-O-N elements. The relative density of this sintered compact stands at 96.5-98%, the area proportion of the grain boundary phase <=10%, and the molar ratio Y/Al >=0.8 Besides, for the sintered compact, the average four-point flexural. strength on the abraded surface stands at >=600MPa, that on the unabraded surface >=600MPa, and the ratio for these flexural strengths >=0.8. |
