Researchers from Georgia Tech and the Indian Institute of Science studied crystal orientation anisotropy of Ti-Pt-Ni-Hf shape memory alloys, and reported results at MS&T 2019 in Portland, Oregon.
In this study, mechanical properties of four shape memory alloys were studied by the spherical nanoindentation technique: Ni40-Pt10-Ti40-Hf10, Ni40-Pt10-Ti35-Hf15, Ni45-Pt5-Ti40-Hf10, and Ni35-Pt15-Ti30-Hf20.
The anisotropy of elastic and plastic properties of each alloy was investigated on different grain orientations. The nanoindentation tests were performed using a 16 µm spherical tip radius; and data were analyzed to extract indentation stress-strain curves. Then indentation elastic modulus (Eind), yield strength (Yind), and hardening rate (Hind) were extracted and presented as functions of the grain lattice orientation in all alloy compositions.
In addition, the effects of the orientation and the alloy composition were investigated on the residual strain after unloading in nanoindentation tests.
Paper Title: Nanoindentation Measurements of Crystal Orientation Anisotropy in Elastic and Plastic Properties of Ti-Pt-Ni-Hf Shape Memory Alloys
Authors: Ali Khosravani, Surya Kalidindi, Georgia Institute of Technology
Manu Mohan, Dipankar Banerjee, Indian Institute of Science
