To provide a die for extruding Al or an Al alloy capable of preventing a crack or a high-temperature wear and abrasion of the die at the time of extruding work to extend the service life of the die by forming a high- temperature abrasion resistant alloy coating in the required portion of the die for extruding the Al alloy so that the die causes no distortion or no peeling.
The required portion of the die surface is formed as a roughened surface of a surface-roughness 5 μmRz or more and coatings of a Co base alloy, a Ni base alloy, a Cr base alloy and other alloys having high-temperature abrasion resistance are formed on the roughened surface through thermal spraying. After forming the coatings of the alloys, the die is held at 500-800°C for a predetermined time or the surface-roughness of the coatings of the alloys is preferably made to 10 μmRz or less. Further, the coating thickness of the alloys is preferably 10 μm to 200 μm.
YAMAGUCHI KOICHI
SHOJI SATORU
KAKIGI TOSHIYUKI
