Microstructural Investigation of High Temperature and Strength Shape Memory Alloys

We submitted a proposal to CINT to conduct research on “Microstructural Investigation of High Temperature and Strength Shape Memory Alloys” and it was accepted. We plan to conduct in-situ TEM nano-indentation experiments on homogenized (precipitation free) and 500°C-3h aged (precipitation size of 20 nm) NiTiHfPd single crystals along [111] and [100] orientations to determine characteristics of the stress-induced martensite reorientation of two samples with different martensite morphologies. We would utilize the CINT Focused Ion Beam (FIB) to fabricate samples and in-situ TEM nanoindentation capabilities at CINT-SNL in collaboration with K. L. Jungjohann (CINT-SNL). O.Anderoglu (LANL) is also a trained user of both the TEM and FIB, and will help H. Tobe in an effort to minimize ramp-up time to conduct meaningful experiments. This study is highly important in order to gain the fundamental knowledge on the effects of precipitates and orientation on the martensite morphology and deformation mechanisms; and to control the shape memory and material properties of NiTiHfPd alloys by tailoring their microstructure. The findings will be compared with nano and micro-indentation and compression tests done at bulk samples. The research findings will be published in journals and presented in conferences to promote the research conducted at University of Kentucky and establish international collaborations. Furthermore, we plan on submitting new proposals to NSF and DOE on high strength shape memory alloys to establish their processing-microstructure-property relationships.