Synthesis, Characterization, and Intrinsic Hardness of Layered Nanolaminate Ti3AlC2 and Ti3Al0.8Sn0.2C2 Solid Solution

The HIPing of TiAl1.9TiC and TiAl0.2Sn1.8TiC reactant mixtures yields Ti3AlC2 and Ti3Al0.8Sn0.2C2 solid solutions, respectively. Rietveld refinement gives a similar to=similar to 3.0786 similar to +/- 0.0001 similar to angstrom and c similar to=similar to 18.589 similar to +/-similar to 0.001 similar to angstrom lattice parameters for Ti3AlC2 and a similar to=similar to 3.0837 similar to +/-similar to 0.0001 similar to angstrom and c similar to=similar to 18.621 similar to +/-similar to 0.002 similar to angstrom for Ti3Al0.8Sn0.2C2. Furthermore, about 23 similar to vol% of TixAly intermetallics is detected in Ti3Al0.8Sn0.2C2 solid solution. The intrinsic hardness, measured by nanoindention tests, is 11.4 similar to +/- 0.7 similar to GPa for Ti3AlC2 and 10.2 similar to +/-similar to 0.6 similar to GPa for Ti3Al0.8Sn0.2C2. Furthermore, hardness values, measured by microindentation tests, are compared with the ones measured by nanoindentation. It is shown that microindentation and nanoindentation performed with large loads lead to underestimated hardness values as several grains are involved in the deformation process. Finally, Young's modulus of Ti3AlC2 and Ti3Al0.8Sn0.2C2 is 260 similar to +/-similar to 10 and 250 similar to +/-similar to 10 similar to GPa, respectively.