High-temperature sliding wear behavior of an intermetallic γ–based TiAl alloy

Abstract

The high-temperature sliding wear behavior of the γ–based TiAl alloy TNM-B1 was investigated using a pin-on-disk apparatus up to 800 °C in air under variation of the counterpart material. Sliding TNM-B1 against a Ni-based pin led to approximately twice as high wear losses compared to like-on-like wear tests up to 400 °C. These severe wear losses were verifiably attributed to a strong material transfer from the TiAl surface to the pin already existing at low temperatures. Moreover, it was proven that there is a distinctive temperature dependent transition from severe to mild wear for both sliding couples due to the formation of protective oxide scales above 600 °C. In this regard, Al- and Ti-rich oxide scales formed on the worn surfaces minimizing direct metal-to-metal contact.