Wear of iron–aluminide intermetallic-based alloys and composites by hard particles

Abstract

In this study, the resistance of alloys and composites based on the intermetallic compounds Fe 3Al and FeAl to wear by hard particles was assessed and compared to the behavior of selected metals, alloys, other intermetallic compounds and ceramics. Pin abrasion tests were performed on these materials at room temperature. Among other things, it was found that as the Al atomic percent in binary Fe–Al increased, the alloys became more abrasion resistant. In summary, the ranking of the alloys in terms of abrasion resistance from the most resistant to the least resistant proceeds as follows: FeAl>Fe 3Al>α-Fe alloy with 16 at.% Al>pure Fe>pure Al. These results are discussed in terms of the hardnesses of the respective alloys. The addition between 40 and 70 vol.% of a hard second phase (e.g. TiC or TiB 2) decreased the wear rate of the Fe 3Al and FeAl composites by an order of magnitude compared to the parent alloy. In addition, solid particle erosion tests were performed on an FeAl alloy, and FeAl+80 vol.% TiC, FeAl+80 vol.% WC, FeAl+80 vol.% TiB 2 cermets at 25, 180, 500 and 700°C, and the results were compared to erosion behavior of several conventional alloys and cemented carbides (WC–Co). The ranking of the erosion resistance of the FeAl alloys and composite materials was as follows: (most resistant) FeAl–WC>FeAl–TiB 2>FeAl–TiC>FeAl (least resistant). This behavior was related to both the cermet microstructure and material removal mechanisms.