In order to increase the service life of casting molds,some improving measures are put forward.The failure reasons of copper plate and its surface coatings are analyzed.In addition,the design of the casting mold,the selection of materials and surface hardening technology are studied.Furthermore,by means of comparison of Ag-Cu and Cr-Zr-Cu metallographic structure photos,Cr enriched metal compounds segregated from the interface of the copper crystal cells is primary cause to the thermal cracks of the Cr-Zr-C...