Alloys with composition of Ta-10 wt.% W and Ta-10 wt.% W-6 wt.% Al, respectively, were prepared by the hot-press sintering process. The oxidation behaviour at 900°C and 1000°C was studied. The oxidation weight gain curves of the Ta–10%W alloy followed the linear law and the final oxidation product was Ta₂O₅ solid solution. Meanwhile, due to the addition of Al, the oxidation weight gain curves of the Ta–10%W–6%Al alloy followed the parabolic law. The final oxidation products at 900°C formed a dense outer layer Al₂O₃ and an inner layer. However, after being oxidised at 1000°C, the oxidation products included Al₂O₃, AlTaO₄ and Ta₂₂W₄O₆₇. Since the dense Al₂O₃ oxide film was consumed by the generation of AlTaO₄, the inward diffusion of oxygen cannot be prevented. The oxidation resistance degraded at 1000°C. The addition of Al significantly improved the oxidation resistance of the Ta-W-based alloy system.

High-entropy carbide (NbTaTiV)C₄ (HEC4), (MoNbTaTiV)C₅ (HEC5), and (MoNbTaTiV)C₅-SiC (HEC5S) multiphase ceramics were prepared by spark plasma sintering (SPS) at 1900 to 2100 °C, using metal carbide and silicon carbide (SiC) as raw materials. Their microstructure, and mechanical and tribological properties were investigated. The results showed that the (MoNbTaTiV)C₅ synthesized at 1900–2100 °C had a face-centered cubic structure and density higher than 95.6%. The increase in sintering temperature was conducive to the promotion of densification, growth of grains, and diffusion of metal elements. The introduction of SiC helped to promote densification but weakened the strength of the grain boundaries. The average specific wear rates for HEC4 were within an order of magnitude of 10⁻⁵ mm³/N·m, and for HEC5 and HEC5S were within a range of 10⁻⁷ to 10⁻⁶ mm³/N·m. The wear mechanism of HEC4 was abrasion, while that of HEC5 and HEC5S was mainly oxidation wear.

Although steel slag exhibits cementitious properties, the addition of steel slag in cement is still limited due to both the presence of excess iron oxides and instability of free lime and periclase. This paper proposes a method for oxidizing molten slag in air, aiming at extraction of superfluous wustite and stabilization of free lime and periclase. Mineralogical characteristics of raw slag and modified products were examined using X-ray diffraction (XRD), scanning electron microscopy equipped with backscattered electron imaging (SEM-BEI), energy dispersive spectrometry (EDS) and thermogravimetric analysis (TGA) with differential scanning calorimetry (DSC). Thermodynamic calculations were performed to aid to discuss the experimental results. The results indicate that non-magnetic wustite and periclase are transformed into magnetic spinel (magnetite/magnesioferrite) after oxidation. Temperature has a significant effect on the formation of spinel. The mass fraction of free lime decreases from 3.54 wt.% to 0.96 wt.% as a result of the conversion from free lime to calcium ferrite.