| 摘要 |
PURPOSE:To increase breakng strength by decreasing graphite occupying ratio in the surface layer, which is in contact with metal, of a graphite substrate than that in the inner layer when a composite target is formed by bonding a graphite substrate with a metal alloy. CONSTITUTION:A graphite substrate 1 that graphite occupying ratio in its surface layer is less than 1.8/2.2 and that in its inner layer is 1.8/2.2 or more is obtained by heating graphite in an atmosphere of gas containing oxygen at 600 deg.C or more, then quenching it in water. W-Re alloy 2 is placed thereon with Zr- 31Mo weld alloy 3 interposed, and they are heated in a vacuum under static pressure to bond them. By this process, a composite target for X-ray tube rotating anode is formed. Since weld alloy 3 and W-Re alloy penetrate in the surface layer in which graphite occupying ratio is low, strength is remarkably increased. Therefore, this process makes it possible to produce a large diameter target. |
