GB1155366A - Method of producing Fe-Cu Alloys - Google Patents

Abstract

1,155,366. Sintered Fe-Cu alloys. CHAS. PFIZER & CO. Inc. June 14, 1966 [July 13, 1965], No.26550/66. Heading C7D. A powdered alloy comprising Fe and 1-50% Cu is made from a powder mixture of a reducible Fe compound and Cu or reducible compounds of Cu and optionally Ni, Co, Mo, W or their reducible compounds, heating the mixture under reducing conditions up to 1150‹C. and at least 100‹C. above the sintering temperature of Cu until the compounds are completely reduced and then heat treating the powder alloy for at least 30 minutes at a temperature between the α-γ transition temperature of the Fe rich phase and a temperature 150‹C. below this transition temperature. The cooled heat treated powder is then compacted and sintered. The mixture containing 1-20% Cu is reduced at 1120‹-1135‹C. and a mixture containing 20-50% Cu is reduced at 950‹-1050‹C., reduction being effected in H 2 , Co, dissociated NH 3 , water gas or producer gas. 8-12% carbon may also be added to the mixture prior to reduction. The mixture should have a particle size less than 250 microns, the Fe compound a size less than 50 microns and the Cu compound a size less than 20 microns. The Fe compound is preferably an oxide in which the O:Fe ratio is at least 0À33 by weight e.g. hematite, magnetite or mill scale and the Cu compound is an oxide or nitrate. Ni may be added as the acetate, Co as oxide, Mo as oxide and W as the oxide up to 6% by weight or a total of 12%. The mixture may be mixed with a binder e.g. a glue or a cellulose. The preferred heat treatment temperature is 825‹-845‹C. and the compacted powder is sintered at 1095‹C. or 1120‹C. in H 2 . The sintered compact may be repressed and resintered.