An investigation into the microstructure and mechanical properties of V2AlC MAX phase prepared by microwave sintering

The present study investigated the mechanical properties and microstructure of V₂AlC MAX phase prepared by the microwave sintering process. The powders mixture of the V-Al-C system with the molar ratio of 2:1.5:1 was mixed through a mixer mill for 10 min in the ethanol media without any aggressive milling condition. The microwave sintering process was performed at the sintering temperatures of 1200, 1300 and 1400 °C without any soaking times and the protective atmosphere in the graphite bed. The XRD patterns showed the formation of the V₂AlC max phase at the sintering temperature of 1200 °C with VC and Al₂O₃compounds. In contrast, the sample sintered at 1300 °C displayed completely matched peaks with the reference pattern of the V₂AlC MAX phase. Moreover, the related XRD patterns belonging to the specimen sintered at 1400 °C demonstrated the formation of VC and Al₂O₃ compounds as the dominant crystalline phases. The microstructure studies also showed the formation of the nano-layered MAX phases at the sintering temperatures of 1200 and 1300 °C. However, in the case of the sintering temperature of 1400 °C, the VC phases turned into the nano-blades shape after the cooling process. The highest bending strength of 189 ± 21 MPa was obtained for the specimen sintered at 1300 °C, while the highest Vickers hardness of 892 ± 15 Hv was calculated for the sample sintered at 1400 °C as the ceramic composite with the VC-Al₂O₃ composition.