Influence of cooling rate on microstructure and mechanical properties of bata processed TC11 alloy

The effect of cooling rate on microstructure and mechanical properties of β processed TC11 alloy is investigated. It is shown that if using water cooling, the precipitation of boundary α phases is prohibited, but much short, fine and disordered needle α phases precipitate within primary β grains. On the contrary, if using air cooling, some continuous and thick α phases precipitate at grain boundary, and much coarse and flat α phases precipitate within primary β grains. It is also shown that the cooling rate has a strong influence on both strength and ductility. The water cooled specimen has a higher strength of about 30 MPa than the air cooled one, and the former possesses an obviously higher ductility than the later. It is concluded that water cooling is one of the most effective method for improving the ductility of titanium alloys.