Impact of aluminum concentration on the synthesis of highly pure Cr2AlC MAX phase

20^th International Conference on Emerging Materials and Nanotechnology

June 25-26, 2018 | Vancouver, Canada

O P Pandey

Thapar University, India

Posters & Accepted Abstracts: J Material Sci Eng

Abstract :

Thapar University, India In recent years, MAX phases achieved significant attention from scientists for their promising practical applications and theoretical values. This fascinating class of materials are layered ternary carbides and nitrides having hexagonal crystal structure. MAX phases exhibit a unique combination of properties of both metals and ceramics such as high thermal and electrical conductivity, excellent machinability, good damage tolerability and superb thermal shock resistance, as compared to binary carbides and nitrides. However, the wide applicability of MAX phases restricts due to cost effective synthesis and their phase stability. In this study, we have successfully synthesized Cr2AlC MAX phase through pressure less sintering route. The impact of aluminum content (10 � 50 mol%) on the phase formation and structural properties of Cr2AlC has been investigated. It is observed that the purity of Cr2AlC MAX phase can be enhanced by varying the aluminum content, even at lower temperatures (1200�1300oC), as compared to previously reported Cr2AlC MAX phase (> 1300oC). The highly pure Cr2AlC is obtained at 1300oC, when the aluminum content in 40 mol%. In addition, the crystallite size is found maximum (28.14 nm) and lattice strain (4.03 �� 10-3) is minimum for highly pure Cr2AlC. Also, oxidation kinetic analysis is performed to estimate activation energy (Eg) by following Kissinger-Akahira-Sunose (KAS) method. The MAX phase demonstrated high oxidation resistance and no mass gain is observed in the TGA curve below 700oC. In addition, two exothermic peaks are observed at ~ 700oC and ~ 1050oC. The former peak is associated the oxidation of excess aluminum present on the surface of MAX phase. While later peak represents the formation of Al2O3 layer over the surface MAX phase