| 摘要 |
PROBLEM TO BE SOLVED: To provide beautiful mechanical fracture surfaces on separating surfaces of a rod and a cap part by constituting it by iron base sintered alloy having the composition in which Ni, Cu, Mo, C having the specified ratio are contained and the remainder is composed of Fe and unavoidable impurities, and having the specified density. SOLUTION: A connecting rod is formed of iron base sintered alloy having the composition in which Ni of 1.5 to 4.5wt.%, Cu of 0.5 to 2.5wt.%, Mo of 0.75 to 2wt.%, C of 0.3 to 0.6wt.% are contained and the remainder is composed of Fe and avoidable impurities, and having the density of 6.8 to 7.4g/cc. Fe-Mo, Ni, Cu, graphite powder are respectively prepared as raw powder, mixed with zinc stearate or ethylene bisstearamide powder as lubricant in metal mold forming, press-molded to form a connecting rod-shaped green compact, the connecting rod-shaped green compact is sintered in the nitrogen atmosphere including hydrogen at 1100 to 1300 deg.C, and the connecting rod shaped sintered body is mechanically fractured into a rod part A and a cap part B. Therefore, the weight is reduced, the excellent fatigue strength is provided, and beautiful fracture surfaces can be provided. |
