Solid-Solution Hardening and Softening

As noted above, since substitutions can be made on either of the three sites in the MAX phases, the number of solid solutions possible is quite high. It is thus not unreasonable to assume, that once the effects of such substitutions have on the mechanical properties are understood, then major improvements should accrue. 

In contradistinction, Ti2AlCo.5No.5, is harder, more brittle and significantly stronger, than the end members Ti2AlC and Ti2AlN, which can be deformed plastically up to 5% strain, even at room temperature [98]. At a temperature of 1200 °C, a solid solution softening effect is observed, the reasons for which are still unclear, although they may be related to the aforementioned interlaminar decohesions. 

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