PURPOSE: To continuosly manufacture a Ti alloy material with superior ductility and high strength, by repeating heating for working twice and by carrying out working in the α+β region at a specified ratio of the working rate in the 1st heating to that in the 2nd heating.
CONSTITUTION: In the finish working of an α+β Ti alloy analogous to an α alloy, e.g., a Ti-6Al-4V alloy, heating for the working is repeated twice. The working rate in the 1st heating and that in the 2nd heating are set so as to adjust the ratio of the working rate in the 1st heating to that in the 2nd heating to 0.7W1.3, and the working is carried out in the α+β region. Each of the working rates is ≤15. An isometric structure can be surely formed at a low cost only by carrying out simple plastic working at low working rates.
NISHIKAWA TOMIO
SUZUKI SHIYUUJIROU
