Experimental Researches on the Tribological Behavior of Composite Materials Sintered with Copper Matrix

Abstract

Particulate materials (fillers) can be used within resistance structures only embedded in a support material called a matrix. Most often, in composite constructions, completely different materials can be combined in such a way that their individual properties reach optimum action. Usually, these are pairs of materials to which one has a bearing function, while the other has the purpose of contributing to taking over the moment of inertia. In this paper, a study is carried out regarding the behavior of abrasive wear of some composite materials with the copper matrix, testing the samples obtained by sintering making for different values of the applied load as well as of the relative sliding speed. Starting from the studied literature, fractions of sintered metallic composite materials were developed and having the copper matrix, which were tested in terms of physical - mechanical and tribological properties. The prepared powders were dosed according to the recipes (Cu 60 ÷ 66.4%, Fe 10%, Sn 7.4%, graphite 3.5 ÷ 25%, SiC 3 ÷ 4%, SiO2 9.7%), and the resulting mixtures have been homogenized in order to achieve homogeneous mixtures that will ensure, finally, a good reproducibility of the physical-mechanical properties for the sintered material. For forming, a cylindrical die having a surface area of 2 cm2 was used. The working pressures varied in the range 5000 ÷ 6000 daN/cm2. The densities obtained for the compressed samples were determined by weighing using the METTLER analytical balance and measured with the micrometer, for volume calculation. The density values for “raw” are in the range 4.47 ÷ 5.01 g/cm3.