Microstructural evolution and refinement of as-forged Ti-43Al-9V-Y alloy after quenching and tempering

It is shown that a uniform and refined fully lamellar microstructure can be generated by tempering the quenched samples in the single a region of as-forged Ti-43Al-9V-Y alloy. The refining effect was mainly connected with the quenched microstructures especially for their substructure, grain size and the residual beta particles after the quenching. A series of beta-decomposed products: martensite plate, massive alpha and coarsened alpha lath with increasing grain size were produced due to the decreasing cooling rate during the wedge-shaped sample quenched into iced brine. In addition, the decomposition of beta directly to gamma has also been observed during the quenching with different cooling rate. The lamellar colony size can be controlled in the range of 25-50 mu m after tempering.