Progress in Nb-Si ultra-high temperature structural materials:A review

摘要

Nb-Si based alloys have the greatest potential to replace nickel-based superalloys and become a new gen-eration ultra-high temperature structural material with service temperature of 1200-1400℃ due to their high melting point,high stiffness,low density,and attractive specific mechanical properties at elevated temperatures.This article reviewed the recent progress in the development of Nb-Si based refractory al-loys.Special attention was paid to the property characteristics,preparation techniques,alloying effects,oxidation resistance and fabrication of Nb-Si based alloy components.Thereafter,the trend of develop-ment in the future was forecasted,including:Optimization of the composition and microstructure of Nb-Si based alloys to achieve a balance of mechanical properties;Comprehensive properties evaluation for Nb-Si based alloys to accumulate sufficient data for engineering applications;Development of practical preparation technology for Nb-Si based alloy components with complex shapes;New multilayer compos-ite coatings for Nb-Si based alloy;Joining technology of Nb-Si alloy to itself and to superalloy.