Production of sintered member

Abstract

Abstract PURPOSE:To produce an iron sintered member having high resistance to fatigue at a low cost by heating a compression molding of iron metallic powder in a nonoxidizing atmosphere and compressing the molding to a high density and subjecting only the surface layer to surface reforming to the higher density. CONSTITUTION:The iron metallic powder consisting of a powder mixture composed of iron powder, copper powder and graphite powder is compressively molded to obtain a green compact having 80-90% density ratio. The green compact is held in the nonoxidizing atmosphere kept at 800-1,000 deg.C and the resultant hot green compact is compressed to obtain a repressed body having >=95% density ratio. The repressed body is sintered at about 1,100-1,300 deg.C temp. in the nonoxidizing atmosphere. The sintered body obtd. in such a manner is subjected to the surface reforming treatment such as shot peening to have >=95% density ratio only within 1mm surface layer. A heat treatment stage may be included between the above-mentioned sintering stage and surface reforming stage at need. The iron sintered member having the high resistance to fatigue and tensile strength is obtd. by the above-mentioned method.

Inventors

• 👤 Yoshitaka Takahashi
• 👤 義孝 高橋

Bibliographic Details