To make a die durable for a long usage without mending by forming an abrasion resistant membrane of a DLC film to a bearing face formed on the mold after it is polished and finished like a mirror.
After forming a bearing face on an aluminum extrusion die by a normal method such as a cutting processing, an electroerosion processing and the like, a mirror-like finishing is applied to the bearing face. Thereafter, a DLC film is coated to the bearing face as an abrasion resistance membrane. DLC is a carbon film having a character resembling to a diamond and is publicly known for itself. An abrasion resistant membrane coating is carried out by a PVD method (physical vacuum evaporation method). The aluminum extrusion die is divided so as to be easier for coating the bearing face, and the DLC film is formed on the divided bearing face. An aluminum extrusion member is manufactured by an extrusion molding, using the aluminum extrusion metal thus formed. Forming of die mark is thus reduced, and the aluminum member of high surface quality can be obtained.
TAKAHASHI KENICHI
IGARASHI TAKANORI
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