High-strength copper-nickel alloy oil-retaining bearing for powder metallurgy and preparation method of oil-retaining bearing

The invention relates to the technical field of powder metallurgy, in particular to a high-strength copper-nickel alloy oil-retaining bearing for the powder metallurgy and a preparation method of theoil-retaining bearing. The oil-retaining bearing comprises components in percentage by mass as follows: 9%-12% of stannum powder, 8%-12% of composite graphite powder, 5%-10% of copper-cladded nickel powder and the balance copper powder and inevitable impurities. Through treatment with a mixed low-temperature diffusion technology, a part of materials are subjected to pre-alloying, and nickel element can be uniformly distributed with cooper and stannum; by design of a sintering process, nickel can be subjected to alloying with copper and stannum, material strength is enhanced, the composite graphite powder is added and taken as a solid lubricant, a lubricating layer is formed around CuSn particles, in the starting moment of a motor, an oil film is not produced, the lubricating layer on the surface plays the role to