Abstract: The conventional hot-working technology of TC4 titanium alloy is to forge the olloy at 30° - 40° c below the transformation temperature and to anneal it subsequently. Under this process the plasticity and thermalstability of the alloy are usually quite good. Unfortunately, the strength of this alloy is relatively low and as a result the tifanium forgings are often made scraped. In this paper, the influence of a new hoi-working technology on microstructure and mechnical property of TC4 alloy is inrestigated. Experiment results show that the network structure, which is in fine and crisscross α+β and sometimes is accompanied with a littie isoaxial α, can be obtamed by high temperature (10℃ below to 5℃ above Transformation point of this alloy) forging, under the same process of water cooling after high temperature forging and strengthening heat treatment afterwards . In this case, the alloy possesses high strength and high plasticity simultaneously. The mechanism of strengthening of this new technology is discussed in this paper.

Key words: detornation temper, microstructure, mechanical property