STRENGTH AND TRIBOLOGICAL PROPERTIES OF SINTERED POWDER COMPOSITE MATERIALS BASED ON COPPER WITH ADDITION OF ALUMINA AND NICKEL OXIDE

摘要

In the paper, the influence of oxide addition on the strength and mechanical properties of a sintered powder material based on copper is described. The increase of alumina content in the composite sintered material leads to decreasing its strength. The most significant decrease of strength is observed when less than 5% of alumina is added to the total volume. A further increase of the alumina content practically leaves the bending strength unchanged and decreases the strength limit in compression insignificantly. The addition of mixture of 80% of the alumina and 20% of the nickel oxide increases the bending strength about 40+50 MPa, and also promotes the formation of a more homogeneous and fine-grained structure, as well as decreases material porosity. The average coefficient of friction of the "sintered composite material - hardened steel C45" pair practically did not change over time. The lowest coefficients of friction were observed for a material containing alumina addition. An addition of Motor Life Professional additive to the lubricant oil reduces the coefficient of friction for the material free of oxides more than 30%. The temperature of friction is reduced by 25/30% and the rate of linear wear decreases 1.4 to 3 times.