  The quest towards expansion of the MAX design space has been accelerated with
the recent discovery of several solid solution and ordered phases involving at
least two MAX end members. Going beyond the nominal MAX compounds enables not
only fine tuning of existing properties but also entirely new functionality.
This search, however, has been mostly done through painstaking experiments as
knowledge of the phase stability of the relevant systems is rather scarce. In
this work, we report the first attempt to evaluate the finite-temperature
pseudo-binary phase diagram of the Ti2AlC-Cr2AlC via first-principles-guided
Bayesian CALPHAD framework that accounts for uncertainties not only in ab
initio calculations and thermodynamic models but also in synthesis conditions
in reported experiments. The phase stability analyses are shown to have good
agreement with previous experiments. The work points towards a promising way of
investigating phase stability in other MAX Phase systems providing the
knowledge necessary to elucidate possible synthesis routes for MAX systems with
unprecedented properties.
