METHOD FOR CASTING MOLD OF TITANIUM AND TITANIUM ALLOY BY FORMING PLASMA THERMAL SPRAYING LAYER AND COATING LAYER ON MOLD SURFACE

摘要

PURPOSE: Provided is a method for casting a mold of titanium and its alloy, which prevents molten metal from being adhered to a mold, reduces surface defects of the cast material and extends a mold life span by forming a plasma thermal spraying layer and a coating-agent layer on the surface of a mold. CONSTITUTION: The mold for cast titanium and its alloy protects the inner wall of a mold by the steps of: thermal-spraying plasma on a mold surface to form a plasma thermal-spraying layer(31); and coating the plasma thermal-spraying layer(31) with a coating material containing ceramic powder to form a coating layer(32). The coating layer(32) is formed after preheating the surface of a cast mold to about 150deg.C. The ceramic powder is one selected from Y2O3, CaO, ZrO2, MgO, and Al2O3. The plasma thermal spraying layer(31) and the coating layer(32) have a thickness of 100 micron below. The coating layer(32) is formed by spraying a mixture consisting of 19.4wt% of ceramic powder, 0.4wt% of a PVB binder, and 80.2wt% of an additive.