压痕-淬冷技术表征氧化锆/铁铝复合材料的抗热震性能

THERMAL SHOCK RESISTANCE OF ZIRCONIA /IRON-ALUMINIDE COMPOSITES EVALUATED BY INDENTATION-QUENCH TECHNIQUES

摘要: 采用压痕-淬冷技术研究了单相 ZrO₂(3Y)及ZrO₂(3Y)/Fe₃Al复合材料的抗热震性能。研究表明: 单相ZrO₂(3Y)及ZrO₂(3Y)/Fe₃Al复合材料的压痕裂纹在热震作用下具有相似的扩展模式: 当△T<△T_U时, 裂纹扩展量较低, 且进行稳态扩展; 当△T>△T_</em>U时, 裂纹发生失稳扩展。复合材料的△T_U明显高于单相ZrO₂(3Y)。ZrO₂(3Y)/Fe₃Al复合材料较高的断裂韧性和导热率、较低的弹性模量和泊松比是导致△T_U升高的主要原因。

Abstract: The thermal shock resistance of ZrO₂(3Y) and ZrO₂(3Y)/Fe₃Al composite was studied using indentation-quench technique. The results show that the pattern of crack growth is similar for the two materials. Low crack growth in a stable manner happened when ΔT<ΔT_U, and cracks grew unstably when ΔT>ΔT_U. The ΔT_U of ZrO₂(3Y)/Fe₃Al composite is higher than that of ZrO₂(3Y), indicating the improved thermal shock resistance. The higher fracture toughness and thermal conductivity and lower elastic modulus and Poisson's ratio of ZrO₂(3Y)/Fe₃Al composite compared with monolith ZrO₂ are the main reasons for the elevated ΔT_U value of ZrO₂(3Y)/Fe₃Al composites.