Research Progress of Lamellar Structure Discontinuous Coarsening Behavior in TiAl Based Alloy

Abstract:

TiAl alloys have a good application prospect in the field of high temperature structural materials due to their excellent specific strength, specific stiffness, corrosion resistance and oxidation resistance. The lamellar structure is an important microstructure of TiAl alloy, and its discontinuous coarsening behavior directly affects the comprehensive properties of the alloy. In this paper, the coarsening types of TiAl alloy lamellar structure are introduced, and the thermodynamics and kinetics of discontinuous coarsening are analyzed. Besides, the research progress of discontinuous coarsening behavior of TiAl alloys lamellar structure in recent years is reviewed. The effects of chemical composition and content, microstructure characteristics, heat treatment process (such as cyclic heat treatment cycle, temperature, time, cooling rate, etc.), additive manufacturing technology and stress on discontinuous coarsening are summarized. Finally, the future development direction of TiAl alloy lamellar structure design and optimization is prospected.