Heat insulation plunger sleeve for die casting machine

摘要

The invention provides a plunger sleeve for use in die casting machines which is outstanding in heat insulating and heat-retaining properties and which is capable of suppressing the drop in the temperature of molten nonferrous metal to the greatest extent and maintaining a stabilized casting operation under pressure. The plunger sleeve comprises a first metal layer made of a metal having high heat resistance and forming the inner periphery of the sleeve, a second metal layer providing the outer periphery of the sleeve, and a ceramic layer formed between the first metal layer and the second metal layer. The ceramic layer comprises a ceramic powder and/or a ceramic fiber consolidated to at least 50% to not greater than 90% in relative density.