| 摘要 |
PROBLEM TO BE SOLVED: To obtain a structure in which specific percentages of tin, iron, carbon, and copper are contained and specific percentages of graphite particles are dispersed in spots by mixing, by weight ratio, specific percentages of iron powder and graphite powder with bronze alloy powder containing specific percentages of tin, compacting the resultant powder mixture into a prescribed shape, and sintering the resultant green compact at specific temperature. SOLUTION: A powder mixture is prepared by mixing, by weight ratio, 5-15% iron powder and 0.3-1% graphite powder with brass alloy powder of 1-6% tin content, and the powder mixture is compacted into a bearing of a prescribed cylindrical shape and is then sintered at a low temperature ranging from 450 to 650 deg.C. By this procedure, a sintered alloy, having an overall composition consisting of 0.8-5.7% tin, 5-15% iron, 0.3-1% carbon, and the balance copper and also having an alloy structure in which 5-15% iron particles and 0.3-1% graphite particles are dispersed in spots throughout a Cu-Sn alloy (bronze) matrix containing 1-6% tin, can be obtained. Moreover, an atomized bronze alloy powder is used as the bronze constituting the matrix. Further, a reduced iron powder and an atomized or electrolytic copper powder are used as the iron and the copper, respectively, and ordinary natural graphite is used as the graphite.
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