Achieving improved workability and competitive high temperature shape memory performance by Nb addition to Ni-Ti-Hf alloys. (15th January 2021)

• Record Type: Journal Article
• Authors: Lemke, J.N.; Gallino, F.; Cresci, M.; Coda, A.
• Is Part Of: Scripta materialia. Number 191(2021)
• Page Start: 161
• Page End: 166
• Publication Date: 2021-01-15
• Subjects: X-ray diffraction -- High temperature shape memory alloys (HT-SMA) -- Mechanical properties (ductility) -- Microstructure -- Crystal structure; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2020.09.032
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: This work depicts how Nb addition to Ni-Ti-Hf alloys increases their ductility without significantly deviating functional performance due to the formation of eutectic constituents composed of soft β-Nb and B19' Ni-Ti-Hf matrix phase. Crucial for designing high performing Ni-Ti-Hf-Nb alloys is considering consequences of the low solubility of Nb in the matrix and the varying solubility of elements in β-Nb on the transformation temperatures. A case study on a drawn Ni-Ti-Hf-Nb wire demonstrates that improved mechanical properties and high transformation temperatures can be achieved by this approach, increasing the possibility for wire drawing of high temperature shape memory alloys. Graphical abstract: Image, graphical abstract