High-throughput screening of shape memory alloy thin-film spreads using nanoindentation

We have demonstrated the utility of nanoindentation as a rapid characterization tool for mapping shape memory alloy compositions in combinatorial thin-film libraries. Nanoindentation was performed on Ni-Mn-Al ternary composition spreads. The indentation hardness and the reduced elastic modulus were mapped across a large fraction of the ternary phase diagram. The large shape memory alloy composition region, located around the Heusler composition (Ni2MnAl), was found to display significant departure in these mechanical properties from the rest of the composition spread. In particular, the modulus and the hardness values are lower for the martensite region than those of the rest of the phase diagram. (c) 2008 American Institute of Physics.