Relationship among forging technology, structure and properties of TC21 alloy bars

As candidate of structural material for advanced domestic aircraft, a new high strength and toughness titanium alloy TC21 was studied focusing on forging technology and microstructure as well as mechanical properties. Two specification ingots and bars were adopted. The results show that basket-weave microstructure is obtained in bars produced by beta finish-forging method; while duplex or tri-modal microstructure appears in bars manufactured by near-beta forging technology. Essential reason affecting structure characteristics is the difference in forging temperature and deformation amount. Variation in lamellar spacing results in fluctuation of properties corresponding to basket-weave microstructure; however, ideal matching of properties can be reached by near-beta forging.