【摘要】 用真空快淬炉制备了名义成分为Ni50 Mn2 7Ga2 3,淬速分别为 2 ,4 ,8m s的快淬态试样 ,并将部分试样热处理 .研究结果表明 ,与铸态相比 ,快淬态试样马氏体相变温度、居里温度均有所降低 ,经热处理后 ,降低的马氏体温度和居里温度会提高 .快淬合金与铸态合金相比更容易获得单相的Ni2 MnGa结构 ,并能使合金主衍射峰从 (2 2 0 )转向(4 0 0 ) ,形成织构 ,热处理后织构消失 .快淬工艺对相变应变和磁致应变的影响表现出复杂性 ,研究发现获得织构的快淬带具有较浇铸态试样更大的相变应变和磁致应变 .更多还原

【Abstract】 Ni 50Mn 27Ga 23 alloy was prepared by melt-spinning at wheel velocities of 2,4 and 8m/s separately. The experimental results showed that the rapid quenching caused the decrease of the martensitic transformation temperature and Curie temperature, while subsequent annealing would increase the depressed values. The NiMnGa specimens with a single-phase structure could be obtained more easily in melt-spun ribbons than in cast alloys. Furthermore, x-ray diffraction studies revealed that the main diffraction peak drifted from (220) to (400) in melt-spun ribbons, which made the texture form, and subsequent annealing made it disappear. The effects of rapid quenching on the phase-transition strain and magnetic field-induced strain are very complicated. It was found that the phase transition strain and magnetic field-induced strain of melt-spun ribbons with texture were larger than that of cast specimens.更多还原