TITANIUM MATERIAL SUPERIOR IN UPSET-FORGEABILITY AND METHOD OF PRODUCING THE SAME

摘要

In finish-cogging a high-purity titanium material into a cylindrical form as the final shape, if cylindrical cogging is performed in all stages of hot forging or if cylindrical cogging is performed in the initial stage of the hot forging, there is no need of peripherally restricting the cylindrical cogging material, so that even if longitudinal upset-forging is effected with an upsetting ratio of 2, the condition that the major diameter/minor diameter ratio of the section after forging is not more than 1.01 can be satisfied, developing superior upset-forgeability. This makes it possible, in producing disk-like targets for sputtering, to minimize cutting loss produced during the rolling and machining and to maximize the yield of products; therefore, the material can be widely used as a semiconductor material for electrodes and the like using a high-purity titanium material.