The Structure and Fracture Pattern of a Сu–Ti–Al–Ni–Fe–C–B Composite after Abrasive Wear

The structure, chemical and phase compositions, hardness, and wear resistance of a Cu–Ti–Al–Ni–Fe–C–B composite prepared by self-propagating high-temperature synthesis (SHS) have been studied. The matrix was formed by Сu–8.5Al–5.0Ni–4.0Fe–1.0Si–0.2Cr aluminum bronze. The powders of Ti, C, and B₄C were used for synthesis. The composite matrix is shown to be a copper-based solid solution, which contains eutectic (Cu + (Ni,Fe)Al) regions with the microhardness of 900 HV 0.1. The strengthening phases are TiC and TiB₂. The microhardness of (γ + TiC) regions is 550 HV 0.1, and that of (Cu + TiB₂ + TiC) regions is 700 HV 0.1. The integral hardness of the composite is 62 HRC. The (γ + TiC) regions are the most plastic structural component of the composite, which are characterized by a high maximum indentation depth, the total mechanical work of indentation and a component of plastic indentation work (φ), and indentation creep (С_IT). Abrasive wear results in cut-off of the surface layers of the structural components (Cu + TiC) and (Cu + (Ni,Fe)Al) with the formation of a smooth surface. The roughness of the sample surface does not exceed 2.8 μm.