超高温铌硅化物基自生复合材料的成分设计及性能特点

Progress in the Compositional Design and Mechanical Properties of Advanced Ultrahigh Temperature Nb-Silicide Based in-situ Composites(RMICs)

从成分设计和性能(主要是室温断裂韧性、高温强度和高温抗氧化性)等方面综述了铌固溶体——铌硅化物基共晶自生复合材料(RMICs)的最新研究进展以及目前仍存在的问题。成分体系从二元向多元化发展,主要有Nb-Si、Nb-W-B-Si、Nb-Mo-Hf-Si、Nb-Ti-Cr-Al-Si、Nb-Mo-W-Ti-Si、Nb-Mo-W-Hf-C-Si 等。该材料的室温断裂韧性接近40MPa·m^(1.2),蠕变强度达到180MPa(1773K/100h)。通过合金化和涂层防护两种方法都可以改善材料的综合性能。

This paper reviews the most recent progress in the compositional design and mechanical properties (such as room temperature fracture toughness,elevated temperature strength and oxidation resistance)of Nb solid so- lution and Nb silicide in-situ composite materials(RMICs).These materials are potential candidates to be used in the temperature range of 1200～1400℃.The alloy systems have been developed from a simple hinary Nb-Si one to complex multi-element alloyed ones such as Nb-W-B-Si,Nb-Mo-Hf-Si,Nb-Ti-Cr-Al-Si,Nb-Mo-W-Ti-Si,Nb-Mo-W-Hf-C-Si and Nb-Ti-Hf-Cr-Al-Mo-Si.The room temperature fracture toughness K_(IC) has reached to about 40MPa·m~,and the tensile creep strength to 180MPa at 1773K for 100 hours in a multi-element alloyed material.The balance among K_(IC), high temperature strength and oxidation resistance would be gained through both alloying effect and protection coat- ings.Further research effort should be made for better balances among these properties in the future.