While being superior in flowability and dummy, stability of density mixing into the production mannered null iron basic powder

摘要

PROBLEM TO BE SOLVED: To provide a method of producing an iron based powdery mixture for powder metallurgy in which the segregation of additives such as a lubricant, graphite powder and copper powder and the occurrence of dust are reduced, the change in fluidity with the lapse of time is reduced, and the variation of apparent density is extremely little.;SOLUTION: Fatty acid which is liquid at an ordinary temperature is added to iron based powder, and primary mixing is performed. Powder for an alloy and metallic soap are added thereto, and secondary mixing is performed. The temperature is raised in the process of the secondary mixing or after the secondary mixing to produce a co-melt of the fatty acid and the metallic soap. Next, cooling is performed while conducting third mixing, and the co-melt is cooled to solidify. The powder for an alloy is stuck to the surfaces of the iron based powder particles by the bonding force of the co-melt. Metallic soap or wax, and an antistatic agent of 0.01 to 0.1 wt.% are added at the cooling, and fourth mixing is performed.;COPYRIGHT: (C)2004,JPO