Preparation And Properties Of W-10cu Composite Materials Research

W-Cu composites have been used widely as a contact material, especially a vacuum contact material, due to excellent electric and thermal conductivity, good electrical and erosion resistance. However, many deficiencies of W-Cu composites prepared by traditional process, such as low density, hardness and electric conductivity that barrier its development in the field of electric switch. In this paper, a new research about the influence from W powder particle size and different mixed W powder consisting of different particle size powder was made to get W-10Cu composite with excellent property.The process of preparing superfine W powder, the preparing and performance of W-10Cu composites were discussed. To increase the density of composites, the influence of mixed powder to composite was researched. The results show that:(1) The AMT powder with a special shell structure exhibiting a high porosity was prepared by spray-drying of aqueous solution of AMT. The superfine W powder was obtained by subsequent calcinations of AMT and reduction with W grain size of about 33nm.(2) Tungsten skeleton with 80.26% relative density was obtained using superfine W powder after sintering 90min at 1350℃. W-10Cu composite with 97.14% of relative density,31HRC and 39.7%IACS was prepared by infiltrated 120min at 1300℃.(3) The rate of shrinkage of tungsten skeleton increased as the increasing of sintering temperature. To satisfy the requirement of infiltrating Cu10wt%, tungsten skeleton was sintered at high temperature. The density of W-lOCu composite increased as the increasing of infiltration temperature. The hardness and electrical conductivity increased at first, but reduced as the increasing of infiltration temperature. The best suitable process parameter is that infiltration temperature is 1300℃and infiltration time is 120min.(4) The density, hardness and electrical conductivity increased as the particle size ratio increasing when two kinds of W powder were matched. The density, hardness and electrical conductivity of W-lOCu composite increased first then reduced as the increasing of particle size ratio of three kinds of W powder, but the electrical conductivity increased as the increasing of particle size ratio. The regularity of W-10Cu composite property of four kinds of particle matching was the same as three particle size mixed. The W-lOCu composite with 98.9% relative density, 28.9HRC and 41.03%IACS was produced after sintering of tungsten skeleton 90min at 1350℃and infiltrating 120min at 1300℃.