Structure, morphology and selected mechanical properties of magnetron sputtered (Mo, Ta, Nb) thin films on NiTi shape memory alloys

The Young's Modulus of both the thin films and thin film/substrate composites were investigated on various scales. For this purpose, indentation experiments were performed using both nano- and microindentation techniques. A comparison of the values of the Young's Modulus of the thin film materials (in bulk, literature data) and the results obtained from nanoindentation shows a very good agreement between the measured data and bulk data. Progressive scratch tests were used to evaluate the adhesion of the thin film materials on the NiTi substrate. These scratch tests suggest that the metallic thin films undergo plastic deformation at larger normal forces. However, no thin film delamination is observed, independent of the material combinations and testing conditions applied.