Recovery stress and shape memory stability in Ni-Ti-Cu thin wires at high temperatures

0368419 - FZÚ 2012 RIV DE eng J - Journal Article
Molnár, Peter - Van Humbeeck, J.
Recovery stress and shape memory stability in Ni-Ti-Cu thin wires at high temperatures.
International Journal of Materials Research. Roč. 102, č. 11 (2011), s. 1362-1368. ISSN 1862-5282. E-ISSN 2195-8556
Institutional research plan: CEZ:AV0Z10100520
Keywords : shape memory alloys * recovery stress * Ni-Ti-Cu * stress relaxation
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 0.830, year: 2011
http://www.ijmr.de/directlink.asp?MK110596

The recovery stress evolution during thermal cycling (heating, isothermal holding, cooling) to temperatures significantly above the austenite finish temperature in Ni –Ti – Cu thin wires was evaluated in a dynamic mechanical analyser DMA TQ800. Ni –Ti–Cu wires were annealed at four different temperatures (350 °C, 450°C, 550 °C and 650 °C). It was observed that the maximum recovery stress significantly decreases with increasing annealing temperature. It was also observed that the recovery stress during four isothermal holdings shows similar behaviour for all annealing temperatures, i. e. stress relaxation occurs after initial stress increase during the first isothermal holding and no stress relaxation is observed during isothermal holdings in subsequent thermal cycles.
Permanent Link: http://hdl.handle.net/11104/0202767