I want to carry out SEM/ optical microscopy of shape memory alloy (NiTi and NiTiNb SMA) samples to study phase transformation due to externally applied stress. My questions are:

1. What etchant is suitable for NiTi and NiTiNb material?

3. How can I remove the oxidation layer on my samples without

causing any deformation/damage to the surface?

4. For phase transformation identification, does the orientation (longitudinal or cross-sectional plane) make any difference? .

4. Any advice on what should I do get the micrographs that show grains and martensite varriants. Please see the attached SEM micrograph. of virgin NiTiNb sample.

Thanks.