Study of two-way shape memory extension spring of narrow hysteresis TiNiCu shape memory alloys

• Published in: Materials letters Vol. 56; no. 3; pp. 284 - 288
• Main Authors: Wang, Z.G, Zu, X.T, Feng, X.D, Zhu, S, Dai, J.Y, Lin, L.B, Wang, L.M
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.2002; Elsevier
• Subjects: Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Extension coil spring; Heat treatment; Martensitic transformations; Materials science; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Thermomechanical training; TiNiCu shape memory alloy; Two-way shape memory effect; Extension coil spring; Heat treatment; TiNiCu shape memory alloy; Two-way shape memory effect; Thermomechanical training; Annealing; Nickel alloys; Cooling; Recovery(properties); Martensitic transformations; Ternary alloys; Experimental study; Dislocations; Shape memory effects; Titanium alloys; Shape memory alloy; DSC; Copper alloys; Coil spring; Thermomechanical treatments; Two way shape memory effect; Hysteresis; Transition element alloys
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/S0167-577X(02)00456-1

Two-way shape memory effect (TWSME) was introduced in a narrow hysteresis TiNiCu shape memory alloy spring by thermomechanical training after a constrained annealing heat treatment. A TWSME extension spring that can extend while heating and contract while cooling using the TiNiCu shape memory alloy was obtained. The result showed that the TWSME recovery rate of the extension spring could be high—up to 58% when thermomechanical training reached 225 cycles after annealing on the constrained condition at 500 °C for 1 h. The TWSME recovery rate still maintains 42% when it was thermally cycled 1100 times. The effect of different heat treatment conditions on TWSME of the springs was also researched. The transformation temperatures and hysteresis were studied by differential scanning calorimetry (DSC) during training transformation.