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This study deals with the development and characterization of FeSi-NiAl-based composite materials, consisting of NiAl matrix and FeSi hardening phase, representing a new generation of tool materials. These composites can compete with conventional materials, such as cemented carbides and high-speed steels, which contain tungsten and cobalt - raw materials classified as critical by the European Union and economically burdened by the current geopolitical situation. The composites were prepared by vacuum induction melting with centrifugal casting in weight ratios of FeSi:NiAl - 1:2 and 2:1. In order to improve structural homogeneity and mechanical properties, the samples were subsequently remelted by the Bridgman directional solidification method at a temperature of 1450 °C with a holding time of 30 minutes and a crystallization rate of 100 mm/h. The microstructure was analyzed using scanning electron microscopy (SEM) and chemical composition was determined by energy dispersive X-ray spectroscopy (EDX). Furthermore, microhardness was evaluated using the Vickers method along with tribological properties, specifically the friction coefficient and wear rate, which are key for practical tool applications. In the as-cast state, the composites showed a randomly oriented dendritic microstructure. In contrast, directional solidification led to significant straightening of the microstructure and a controlled distribution of individual phases. This process resulted in a significant leveling of mechanical and tribological properties in both compositions compared to the as-cast state. This indicates higher structural homogeneity and more stable material behavior under operating conditions, making these composites suitable for advanced engineering applications.
Keywords: Iron silicide, nickel aluminide, sustainability, directional solidification.© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.