Control of a fine-grained microstructure for cast high-Cr TiAl alloys

In order to refine the cast microstructure and improve the mechanical property of TiAl alloy, the element of Cr was chosen for alloying. Experimental results show that the refinement was achieved and the cast microstructure was controlled to be fine by inducing β solidification due to the addition of a high content of Cr. Furthermore, the cast microstructure was optimized to be a fine fully lamellar (FL) one by one-step heat treatment. And with the microstructure refinement and optimization, the tensile strengths of the present cast alloys both at room and high temperatures were improved to exceed the strength level for traditional cast TiAl alloys, and reached that for wrought TiAl alloys.