Preparation of the Ti-Al-Si with the Low Content of Silicon by Powder Metallurgy

Abstract

Ti-Al-Si alloys are among the most promising intermetallics, which show a combination of low density and good oxidation resistance. These positives predetermine Ti-Al-Si alloys for applications in the automotive and aerospace industries. In the future, they could substitute existing materials for high-temperature applications (stainless steels, and especially nickel alloys), that high density significantly limits their application. The use of intermetallic compounds based on Ti-Al-Si would therefore lead in particular to a reduction of the weight of the structures, which is highly desirable in the aerospace industry. Due to the lightweight construction, fuel consumption and transport costs in general would also be reduced. The disadvantage of Ti-Al-Si alloys is their brittleness at room temperature. Decrease of brittleness can be achieved by suitable chemical composition and also by choosing the suitable preparation. Therefore, powder metallurgy processes appear to be the right way to prepare these intermetallics. This work deals with the preparation of intermetallic alloys based on Ti-Al-Si system with the low content of silicon by powder metallurgy using mechanical alloying and followed compaction by Spark Plasma Sintering.