The aim of the research was to disclose the performance of ceramic-metal composites, in particular TiC-based cermets and WC-Co hardmetals, as tool materials for friction stir welding (FSW) of aluminium alloys, stainless steels and copper. The model tests were used to study the wear of tools during cutting of metallic workpiece materials. The primary focus was on the performance and degradation mechanism of tool materials during testing under conditions simulating the FSW process, in particular the welding process temperature. Carbide composites were produced using a common press-and-sinter powder metallurgy technique. The model tests were performed on a universal lathe at the cutting speeds enabling cutting temperatures comparable the temperatures of the FSW of aluminium alloys, stainless steels and pure copper. The wear rate of tools was evaluated as the shortening of the length of the cutting tool nose tip and reaction diffusion tests were performed for better understanding of the diffusion-controlled processes during tool degradation (wear). It was concluded that cermets, in particular TiC-NiMo with 75–80 wt.% TiC, show the highest performance in tests with counterparts from aluminium alloy and austenitic stainless steel. On the other hand, in the model tests with copper workpiece, WC-Co hardmetals, in particular composites with 90–94 wt.% WC, outperform most of TiC-based cermet, including TiC-NiMo. Tools from ceramic-metal composites wear most commonly by mechanisms based on adhesion and diffusion.

From the outlook of healthcare, economic importance and supply risk, utilisation of raw materials like tungsten, cobalt and nickel should be reduced or replaced with other metals. Nontoxic titanium carbide and iron are the top-of-the-line solution for displacing these materials. Our focus was on conventionally fabricated titanium carbide-based cermets with a chromium ferritic steel binder. To study microstructural evolution, specimens were sintered at different temperatures (600–1500°C). We used a scanning electron microscopy, X-ray diffraction and differential scanning calorimetry to analyse the microstructure and phase formation of the cermets. Our results showed that during the solid and liquid phase sintering of the TiC–FeCr cermet, chromium ferrous complex carbides M₇C₃ are formed and as a result, chromium content in the binder phase is decreased. Alloying TiC–FeCr cermets with strong carbide formers improves the structural homogeneity of the cermets. Also, mechanical characteristics (hardness, fracture toughness) were evaluated.

In the context of rising power densities in electrical machines, additive manufacturing presents an opportunity to develop more powerful thermal solutions. However, the physical properties of objects manufactured using this process remain unclear. This research examines the directional thermal and electrical conductivities of aluminum alloy (AlSi10Mg) and silicon steel (Fe-3.7%wt. Si) samples produced via laser powder bed fusion (LPBF), both prior to and following heat treatment. The findings indicate that the as-built aluminum samples exhibit higher conductivities in the orientation parallel to the LPBF build direction, while annealing results in higher conductivities overall and an absence of anisotropy. On the other hand, the silicon steel samples show constant conductivities and lack of anisotropy both before and after heat treatment. These results have practical applications in the design of additively manufactured electrical machines, where the thermal and electrical resistance of the materials have a major impact on thermal and electromagnetic performance.

Structure formation and properties of chromium carbide-based cermets with iron–titanium binder were investigated. Chromium carbide (50–70 wt%), Fe, and Ti (Fe : Ti ratio 4 : 1 as the binder phase) powders were milled in an attritor and a ball mill, compacted, and sintered at different temperatures and for different periods in vacuum. The microstructure, phase formation, and the composition of cermets were studied using XRD and EDS analysis and SEM. The results show that during the sintering of the Cr₃C₂–Fe–Ti composite at temperatures above 1000 °C, diffusion of chromium and carbon into the ferritic matrix and Cr₃C₂ recrystallization into the chromium ferrous dicarbide (Cr,Fe)₂₃C₆ and the formation of chromium solid solution in the iron matrix (Fe(Cr) take place. Titanium participates actively in the interaction process, which leads to the formation of TiC carbides even at 1200 °C. The mechanical properties (hardness, fracture toughness) and corrosion resistance in salt water were studied. Cermets sintered at lower temperature during a longer period demonstrated the best complex of mechanical properties.

Friction stir welding is a solid-state joining process that uses a non-consumable tool to join materials by mixing them mechanically in the weld area instead of melting them. The high-quality friction stir welding (FSW) process temperatures are in the range of 400–500 °C. Adhesive wear is suggested to be the main wear mechanism for the FSW tool. Adhesive wear testing should be performed at the weld temperature or close to the welding process temperatures for better simulation of real-life FSW tool wearing conditions. Adhesive wear tests of three FSW tool materials, WC–Co and TiC based with NiMo and FeCr binders at temperatures of 70 °C (low) and 400 °C (high) were performed by turning aluminium alloy AW6082-T6. The higher temperature in the cutting zone was achieved by increasing the cutting speed. To measure the temperature at the interface of the cutting tool and the workpiece, a novel method based on the thermoelectric effect was used. The wear was determined as the change of the geometry of the cutting edges of the tool. Microscopic investigations were performed by using scanning electron microscopy. The distribution of chemical elements and the chemical composition of the tool cutting edge were analysed by energy dispersive X-ray spectroscopy. The TiC-based cermets (TiC–NiMo and TiC–FeCr) demonstrated superiority over WC–Co cemented carbide at both low (70 °C) and high (400 °C) temperatures. The highest wear performance at the low temperature was shown by the Fe-alloy bonded composite TiC–FeCr while at the high temperature the Ni-alloy bonded cermet TiC–NiMo had the highest wear performance.Â