Research on Titanium Alloys with High Toughness and High Damage Tolerance
The recent shift in the design focus for aeroplanes from strength to damage tolerance has led to a subsequent shift in the focus of Ti alloy research. China first started to research Ti alloys with damage tolerance from the year 2000. The first product stemming from this research is a Ti alloy with high strength, high toughness and damage tolerance (TC21). TC21 exhibits high strength (UTS 1100MPa), high fracture toughness (K1c 70MPa.m1/2) and a low crack propagation rate (da/dN being similar to Ti-6-4 with annealing). Another Ti alloy, named TC4-DT, has also been produced. It has moderate strength, along with high toughness and damage tolerance (UTS 900MPa, K1c 70MPa.m1/2, da/dN being similar to Ti-6-4 with annealing). Both TC21 and TC4-DT are now undergoing rapid development, with the former alloy also being applied to a full scale aeronautical application. Both TC21 and TC4-DT have promising futures in the industry. They will be the main Ti alloys with damage tolerance utilised in the Chinese market.
M.S. Dargusch & S.M. Keay
Y. Q. Zhao et al., "Research on Titanium Alloys with High Toughness and High Damage Tolerance", Materials Science Forum, Vols. 618-619, pp. 97-100, 2009