Refrakter metal içerikli yüksek entropilli alaşımların üretilmesi ve geliştirilmesi

In the present study, the production of CrFeNiMEIMEII (ME = Mo, Nb, Ta, V, W) high entropy alloys containing refractory metals was carried out using self-propagating high-temperature synthesis (SHS) technique. The fourth and fifth elements constituting the HEA composition were selected among the refractory metals. Equiatomic alloys of CrFeNiMoNb, CrFeNiTaMo, CrFeNiNbV and CrFeNiVW have been produced. The first series of thermodynamic analyses were realized to calculate the specific heat and adiabatic temperature values of the SHS reactions for the targeted alloys. The reduction experiments were carried out for the thermodynamically competent SHS reactions. The chemical, phase, and microstructure analyses of the obtained products were realized, and their mechanical properties were examined. In the SHS experiments, aluminothermic and silicothermic reductions were performed. Different metal oxide powders (Fe2O3, Cr2O3, NiO, MoO3, V2O5, Nb2O5, WO3, Ta2O5) were utilized as raw materials, and aluminum and ferrosilicon powders were used as the reducing agents. The final products were characterized using XRF, XRD, SEM/EDS, and hardness tests. The metallic distributions on the products and metal recovery efficiencies were calculated depending on the chemical analyses. Among the refractory metals, the highest recovery efficiency was achieved in W and the lowest recovery efficiency in Ta.