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In this study, the Ti2AlC MAX phase was produced by mechanical alloying (MA) and spark plasma sintering (SPS) of a mixture of Ti, Al and C powders with a molar ratio of 2:1.1:1. The time of the mechanical alloying process and sintering process temperature were selected as variables, and their effect on the properties of resulted samples was investigated. SPS process was performed on the samples at temperatures of 1000, 1100 and 1200 °C and under the pressure of 30 MPa for 20 min. The cyclic oxidation behavior of the samples was then investigated. The density and hardness of the samples were also examined. The results showed that the best specimen had a density of 4.2 gr cm−3 and a hardness of 995 HV. According to the x-ray diffraction patterns, it was found that the Ti2AlC MAX phase has been formed in all samples. The cyclic oxidation process was performed for 50 h on the selected sample at temperatures 1200 and 1350 °C. The results of oxidation test showed that Al2O3 and TiO2 oxide layers formed with good adhesion on the substrate surface. The weight gain equation of the oxidation test was obtained powerfully at temperatures of 1200 and 1350 °C, where the oxidation constant (ko) increased from 8 × 10–4 to 9 × 10–3 mgn h−1, respectively. In this study, the best results were obtained by MA time of 24 h and then SPS process at the temperature of 1200 °C. [ABSTRACT FROM AUTHOR]

In this study, the WC-FeAl composite was synthesized by mechanical milling and spark plasma sintering. The isothermal oxidation behaviour of the WC-FeAl composite was evaluated and compared with a commercial WC-Co composite at the temperature range of 700–900  ℃ . The results showed that the oxide layer formed in the WC-FeAl composite contained FeWO 4 , FeAlO 3 , and WO 3 phases at all tested temperatures. The XRD patterns indicated that the intensity of FeWO 4 and FeAlO 3 phases enhanced with increasing the oxidation temperature. The formation of these two phases was related to the diffusion of Fe and Al elements from the binder phase to the oxide layers. As a result of the presence of FeWO 4 and FeAlO 3 phases, more compact oxide scales were formed, and the volume of voids and cracks was decreased as compared to the WC-Co composite. The plot of specific mass variations as a function of time illustrated that the mass gain for WC-FeAl composite was almost half of WC-Co composite. [ABSTRACT FROM AUTHOR]