MANUFACTURE OF COMPOSITE BILLET FOR HYDROSTATIC EXTRUSION

摘要

PURPOSE:To prevent seizing on a die face in hydrostatic extrusion and to efficiently obtain products having excellent surface quality by covering the surface of a difficult-to-form metal billet with a specifically thick outermost layer containing an easy-to-form metal by a plasma thermal spraying. CONSTITUTION:The surface of a difficult-to-form metal billet 1 is covered with a >=10 mum thick outermost layer 2 containing an easy-to-form metal by a plasma thermal spraying. The covering by the plasma thermal spraying is easy and a prescribed thickness layer is formed on all the surface in a short time. Thus, seizing on the die surface in hydrostatic extrusion is prevented and removal of the easy-to-form metal from the composite stock after extrusion is facilitated, so that products having excellent surface quality are efficiently obtained.