Superelasticity and shape memory effects in polycrystalline Ni-Mn-Ga microwires

作者：Qian M F; Zhang X X^*; Witherspoon C; Sun J F; Muellner P

来源：Journal of Alloys and Compounds, 2013, 577: S296-S299.

DOI：10.1016/j.jallcom.2011.10.117

• Ni-Mn-Ga
• Melt-extraction
• Superelasticity
• Shape memory effect

Non-stoichiometric Ni49.9Mn28.Ga-6(21.5) microwires with a diameter of 30-80 mu m and cellular grain size of 1-3 mu m were developed by melt-extraction. The superelasticity and shape memory effect of the microwires were investigated on a Dynamic Mechanical Analyzer (DMA Q800). The onset critical stresses for austenite to martensite transformation increase linearly with temperature and can be described by Clausius-Clapeyron relationship. The martensite to austenite transformation upon unloading only at temperatures at least 11 degrees C higher than the martensite start temperature. The as-extracted microwire was loaded in its martensite state to a strain of 2.7% without breaking and 92% plastic deformation strain recovers upon heating.

• 出版日期2013-11-15
• 单位哈尔滨工业大学