Development of novel microstructural control technique for enhancing the deformability (superplasticity) in industrial Ti alloys


 A research group of Chiba lab. (Hiroaki Matsumoto and Akihiko Chiba) has succeeded in developing the novel Ti-6Al-4V alloy showing the low temperature- high speed superplastic behavior, which was collaborated with NHK Spring Co., LTD and supported by NEDO.

 Superplasticity in industrial microcrystalline Ti-6Al-4V (mass%) alloys is exhibited under high temperatures of more than 1123 K and low strain rates of less than 10-3s-1, thereby restricting their practical application to specialized areas such as aerospace. We herein identify a new type of Ti-6Al-4V alloy exhibiting low-temperature (below 973 K)–high-strain-rate (10-2s-1) superplasticity. The ultrafine-grained Ti-6Al-4V alloy was produced by simple hot working of an α′-martensite microstructure alloy, and it has a great potential for application as cost-affordable next-generation superplastic Ti alloy.

 This result was reported in the newspaper of NIKKAN KOUGYO SHINBUN (Sep 18, 2012), KAGAKU KOUGYO SHINBUN (Sep 18, 2012), NIKKAN JIDOUSYA SHINBUN (Sep 18, 2012) and KAHOKU SHINPOU (Oct 1, 2012).