Phase transformation behavior and microstructures of rapidly solidified Co-Ni-Ga alloys
Phase transformation behavior and microstructures of rapidly solidified Co-Ni-Ga alloys
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DOI：
10.1016/j.msea.2005.12.049
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发表时间：
2006-11
期刊：
影响因子：
6.4
通讯作者：
Y. Kishi;Z. Yajima;K. Shimizu;T. Okazaki;Y. Furuya;M. Wuttig
中科院分区：
文献类型：
--
作者：
Y. Kishi;Z. Yajima;K. Shimizu;T. Okazaki;Y. Furuya;M. Wuttig
研究了Co-Ni-Ga合金薄带的马氏体相变行为、磁性能和显微组织，并与Co-Ni-Ga合金块体进行了对比。用电磁控制单辊快淬装置制备了40-60μ m厚的合金薄带。Co-Ni-Ga薄带的马氏体相变特征与块状样品相似。然而，在带状物中的转变温度高于散装，这表明应力诱导马氏体的形成。Co-Ni-Ga薄带的矫顽力强烈依赖于外加磁场的方向。在θ=70°（θ是磁场与带平面之间的角度）时获得最大矫顽力。这种磁性能的各向异性被认为是快速凝固薄带的特征。带状马氏体相的微观结构与块状样品中的马氏体相的微观结构相似，即光学显微镜和扫描电子显微镜显示典型的透镜状形状，透射电子显微镜显示内部孪晶和选定区域电子衍射图案上的特定条纹。
Martensitic transformation behavior, magnetic properties and microstructures of Co–Ni–Ga alloy ribbons are investigated and contrasted with those of Co–Ni–Ga bulk alloy. The rapidly solidified 40–60μm-thickness ribbons of the alloy were prepared by an electro-magnetically controlled single-rolled melt-spinning apparatus. Martensitic transformation characteristics of the Co–Ni–Ga ribbons resemble those of bulk samples. However, transformation temperatures in the ribbons are higher than those of the bulk, suggesting the formation of stress-induced martensites. Coercive force of the Co–Ni–Ga ribbons strongly depend on the direction of the applied magnetic field. Maximum coercive force is obtained at θ=70° (θ is the angle between the magnetic field and the ribbon plane). This anisotropy of the magnetic properties is considered to be characteristics of the rapidly solidified ribbons. Microstructures of the martensitic phase in the ribbons are similar to those in the bulk samples, that is, optical and scanning electron microscopies reveal a typical lenticular shape and transmission electron microscopy shows internal twins and specific streaks on selected area electron diffraction patterns.