Microstructure and wear behaviour of FeAl-based composites containing in-situ carbides

Abstract

Iron aluminides containing carbon are promising materials for tribological applications. Because of graphite formation at higher (>20 wt%) Al-contents the addition of carbon to FeAl-based alloys has not been successful. The graphite precipitation may be avoided by addition of Zr or Ti. Dry sliding wear behaviour of FeAl-based alloys containing 1–1.5 wt% carbon with quaternary addition of Ti or Zr has been studied using ball-on-disk wear test. Effect of sliding speeds and applied loads is investigated and correlated with mechanical properties. Wear resistance of FeAl-based alloys is found to be significantly improved on addition of Ti /Zr. This is attributed to the high hardness of alloy carbides. The lower load-bearing capacity of graphite flakes in localized region was found to increase the wear rate of the alloy. The carbides such as Fe 3 AlC 0 . 5 , TiC and ZrC are embedded in the matrix after sliding wear without destruction or delamination. This significantly affects the wear resistance of FeAl-based alloys.