Complex optimization of arc melting synthesis for bulk Cr2AlC MAX-phase

A complex optimization of the arc melting synthetic approach was performed to enhance the phase purity of Cr2AlC MAX-phase in the bulk form. Optimization steps included the initial ratio of 2Cr: xAl: 1C, variation through a change in Al content (i.e. x ranging from 1 to 1.5), tuning duration of the post-annealing thermal treatment and adjustment of the melting chamber pressure. The use of Cr3C2 as a precursor in place of Cr and C mixture has also been tried. It was found that Cr2AlC MAX-phase forms as the predominant phase when a stoichiometric ratio 2Cr: 1.3Al: 1C is used. By keeping this stoichiometry constant, the melting chamber pressure was then adjusted to further improve the phase purity of the samples. It has been established that the use of Cr3C2 is not an appropriate way to improve sample purity and promote homogeneity in the carbon distribution. The establishment of an optimized arc fusion protocol for parental Cr2AlC is a necessity for further successful mass synthesis of the substituted (Cr1-xMnx)2AlC MAX-phase.