Flame-retardant mechanism of TiAl alloy by frictional ignition method

TiAl is used as the preferred material for aero-engine low-pressure turbine blades, which is also faced with similar problems of “Titanium fire” under long-term high temperature service conditions. In this paper, the micro-combustion behavior of TiAl is discussed. It is found that the flame-retardant of the TiAl alloy has better performance compared to that of TC11, TA11. In this regard, the higher content of Al and Nb is identified as the primary reason for the superior flame-retardant performance for TiAl alloy. Moreover, the segregation serves as a transport channel for atoms and entraps oxygen atoms during the process of extended combustion. The three-stage combustion model before deflagration is presented. Furthermore, the flame-retardant mechanism before and after deflagration is explained, highlighting the main reason behind the formation of the final morphology of the alloy after combustion.