Dependence of the tribotechnical properties of the cast composite material of the [Al — FeCr] system, obtained using a dispersed-filled gas model, on the parameters of its microstructure

Abstract

Analysis of scientific and technical published works and sources of patent information made it possible to formulate and set the goal of the performed scientific research work (R&D). By inoculating cast Al-alloy grade AK12 of DSTU 2839:1994 with dispersed intermetallic FeCr in the “volume” of the casting mold (CM) during casting according to gasifying models, samples of zero-dimensional cast composite material (CCM) of the [Al — FeCr] system were obtained. The application of metallographic analysis (MGA) showed that the zero-dimensional CCM of the [Al — FeCr] system has an optimal microstructure, and the parameters of its tribostructure (the specific number of inclusions of the σ-phase and its dispersion) not only change along the height of the cast samples, but also depend on each other. The results of the wearability tests of the material under conditions of friction showed, that the tribotechnical properties (workability of the counter-body material and CCM of the [Al — FeCr] system and the coefficient of sliding friction of the pair “CCM of [Al — FeCr] system — steel 40X” is depending not only on the height composite casting, as well as from the parameters of its tribostructure. The MGA showed, that after testing the zero-dimensional CCM of the [Al — FeCr] system and the control casting during wear under conditions of friction, it was experimentally proven that the activation of the counter-body material and the coefficient of friction for steam sliding “Al-alloy AK12 — steel 40X” as a result of reinforcement (composite strengthening) of cast Al-alloy grade AK12 with dispersed intermetallic FeCr, on average, increases from 1.15 mg/(cm2·km) and 1.77 to 3.75 mg/(cm2·km) and 1.98, respectively. In contrast, its wear, on average, decreases from 17.85 mg/(cm2·km) to 14.15 mg/(cm2·km).