Effect of B4C content on microhardness and sliding wear behavior of cold sprayed aluminum matrix coatings

The work is devoted to the experimental study of the effect of the B4C particles content on the microhardness and sliding wear behavior of a composite aluminum matrix coating produced by cold spray method. Using the technique of spraying mechanical powder mixtures, composite aluminum matrix coatings with boron carbide content of 3 – 17 vol.% were obtained. The coatings were examined by optical and scanning electron microscopy, X-ray diffraction analysis, and optical profilometry. The introduction of 17 vol.% boron carbide made it possible to increase the microhardness of the aluminum coating by approximately 1.5 times (up to 72.4 HV0.3). It was shown that the addition of carbide particles in the content range under consideration has practically no effect on the volume loss of the coating material during sliding wear. The results of measuring the coefficient of friction showed that with an increase in the test distance, the friction coefficient first decreases, while coatings with a higher content of the ceramic component correspond to lower friction coefficients. With a further increase in the test distance, the coefficient of friction increases, while the influence of the ceramic component on the coefficient is minimized.