中文摘要：

Nb-Ti-Cr-Si基超高温合金具有良好的高温强度和高温抗氧化性能,但室温断裂韧性较差。为了提高该合金的室温断裂韧性,分析了该合金室温断裂韧性较低的原因,对有坩埚整体定向凝固技术、整体定向凝固＋高温均匀化处理和热压烧结法等工艺对Nb-Ti-Cr-Si基超高温合金的室温断裂韧性的影响做了评述,指出了提高该合金室温断裂韧性将来努力的方向。

英文摘要：

Nb-Ti-Cr-Si based ultrahigh temperature alloy possesses good high temperature strength and high temperature oxidation resistance,but its room temperature fracture toughness is poor.In order to improve room temperature fracture toughness,the reason of poor room temperature fracture toughness are discussed,and the effects of integrally directional solidification with the use of a crucible,directional solidification after homogenization treatment and hot press technologies on the room temperature fracture toughness of Nb-Ti-Cr-Si based ultrahigh temperature alloy are reviewed.Finally,the future direction to regarding room temperature fracture toughness of these alloy are proposed.