Study On Electroless Cu Plating Of Mo Powders And Sintering Process

Mo-Cu material is a pseudo alloy. It is made up of Mo which has high melting point, low heat expansion coefficient and Cu with high electrical conductivity, high thermal conductivity. Mo-Cu alloy has the advantages of a stable performance, resistance to erosion and a high density. It has widely used in electronic packaging materials, heat sink materials and aerospace precision instrument parts, so it has broad prospects for development.This experiment uses the method of electroless Cu plating of Mo powders with the liquid sintering Mo-Cu alloy. Discussing the pretreatment process, plating process and sintering process, we got composites with a high density and high conductivity prepared by optimizing the process parameters. The study of this topic can not only find a good method to fabricate Mo-Cu alloy with good properties, and also provide a powerful guarantee for the mass production and widespread use.Through the study of the pretreatment of Mo powder, including powder dispersion, degreasing, coarsening, sensitization and activation a total of five steps. Improving Mo powder surfactant, reducing the composite powder agglomeration, improving the binding properties of Mo and Cu greatly, is conducive to the implementation of the chemical plating.Through the discussion about electroless plating process parameters, and the orthogonal experiment was carried out, eventually determine the electroless plating solution. Stabilizer concentration of 2,2’-bipyridine was 20 mg/L, the deducing formaldehyde content 24 ml/L, the main salt content of copper sulfate pentahydrate was 15-20 g/L, p H value of 11.5, bath temperature is 50℃, compelling agents using acetic acid disodium and potassium sodium tartrate compelling agent system consisting of dual, speed of 40 r/s. After optimization package the Mo and Cu composite powder coated with a uniform complete.Through the discussion about sintering process, determining the sintering temperature 1150℃, keep 90 min. Sintering temperature has a great impact on the microstructure, density, micro-hardness and electrical conductivity of the alloy. After sintering process optimization, Mo-Cu alloy have a microstructure reticular structure, compact and uniform, without obvious defects. Density reached 96.1%; electrical conductivity of 44.56%(IACS), have a good conductive properties; the hardness value can be 179.2 HV.Performance liquid phase sintered of Mo-Cu alloy was analyzed. Founding that with increasing temperature, density, micro-hardness, conductivity alloys are on the rise, microstructure is also showing the reticular structure. This is due to the enhanced ability of Cu’s flowing. Cu filling the pores in the capillary force reduces the number of pores in the alloy. But when the temperature exceeds 1150℃, the performance indicators are in decline alloys. This is because of the strong liquidity overflow Cu outward appearance alloy internal holes.