Study of the “All-Round-Effect” generated by aging in traction in a Ni rich TiNi shape memory alloy

• Published in: Journal of alloys and compounds Vol. 516; pp. 5 - 8
• Main Authors: Amireche, R., Morin, M., Belkahla, S.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 05.03.2012; Elsevier
• Subjects: All Round Effect; Cooling; Cross-disciplinary physics: materials science; rheology; Engineering Sciences; Exact sciences and technology; Intermetallics; Martensitic transformations; Materials; Materials science; Nickel; Nickel base alloys; Nickel titanides; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Shape memory alloys; Solid solution, precipitation, and dispersion hardening; aging; Stresses; Ti 3Ni 4; TiNi; Titanium base alloys; Titanium compounds; Treatment of materials and its effects on microstructure and properties; Ti 3Ni 4; Shape memory alloys; TiNi; All Round Effect; Differential scanning calorimetry; Nickel alloys; Phase transformations; Martensitic transformations; Thermal cycle; Coherent precipitate; High temperature; Bending stress; Heat treatments; Titanium alloys; Tensile stress; Shape memory alloy; Internal stresses; Ti; Aging; Two way shape memory effect; Ni; Alloys; Cerium alloys; Static stress; R-phase transformations; TiNi shape memory alloys; Two-way shape memory effect; Memory effects; Shape memory effect; Coherent precipitates; Quantitative measurement
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2011.11.154

Following aging under stress, Ni-rich TiNi shape memory alloys are subject to a two-way shape memory effect known as the “All Round Memory Effect” (ARME). The latter causes a sample to return to its high temperature shape during heating after being spontaneously deformed on cooling during martensitic and R-phase transformations. This effect has been thoroughly studied for stresses in bending. In this work, we were able to generate ARME with tensile stresses, making it possible to make more quantitative measurements of the effect. Application of a static stress opposite spontaneous deformation during cooling also allowed quantifying the magnitude of internal stresses caused by Ti 3Ni 4 coherent precipitates during aging.