Development of Heat Resistant Aluminum Composite with Minor Addition of Alumina Nanofibers (Nafen

This article describes development of an aluminum composite with a matrix of mixed powdered aluminum, nickel, copper, and boron hardened by 0.01–0.1 wt % alumina nanofibers (Nafen™). The composite samples have been produced by conventional powder metallurgy including pressing and sintering in vacuum furnace. The microstructure and fine structure of aluminum composites, average grain diameter, density, phase composition, Vickers microhardness, and ultimate bending strength at ambient temperature and at 300°C have been analyzed. According to X-ray diffractometry, the samples contain the phases of Al, Al3Ni, CuAl2, Al7Cu23Ni, and Ni4B3. The microhardness increases monotonically with concentration of alumina nanofibers. It has been established that, at ambient temperature, the strength of the samples with 0.01–0.1 wt % of alumina nanofibers is higher by 30% on average than that of the matrix. During tests at 300°C, the best result has been shown by the sample with 0.01 wt % of nanoparticles; its strength was by 14% higher than that of the matrix.