The influence of alloying elements on tribological properties of Fe-Cu-C based metal matrix composite bearing materials produced by powder metallurgy

Bearing materials are used in many industrial applications such as automotive, marine, aviation and hydroelectric power plants. Powder metallurgy is preferred because it is economically more advantageous in the production of this type of material. The main requirement in bearing materials is high tribological properties at a low cost. Therefore, the lower coefficient of friction and wear rate in the bearing materials are among the desired properties. In this regard, the tribological properties and other mechanical, physical, and microstructural properties of the produced samples were investigated in this study. Copper and graphite powder with 5 wt.% Mo, Ni, Al, Cr, and W was added to the base alloy of iron. After the production, density measurements, microstructural characterizations, hardness measurements, and dry friction wear tests were carried out on the samples. Analyzing the results, it was found that the highest density value was achieved in the base alloy. Furthermore, a density of over 90% was achieved in all samples. On the other hand, predominantly ferrite and pearlite phases were observed in the microstructure. When the hardness results were examined, it was determined that the Cr added alloys had maximum hardness. In the evaluation of tribological properties, it was shown that Ni alloy had the lowest friction coefficient and Al alloy had the highest friction coefficient. Considering the wear rates, it was seen that the alloy with the lowest wear rate was Cr and the highest wear rate was the alloy with Al additives.