Co(-Fe)-B-Si-Nb块体非晶合金

Bulk Metallic Glasses of Co (-Fe)-B-Si-Nb

利用团簇线方法和微合金化原理研究了Co基Co(-Fe)-B-Si-Nb多组元合金体系中块体非晶合金的形成。首先,确定Co-B-Si三元体系为基础体系,利用团簇线(体现在三元体系中为二元特殊团簇与第三组元的连线)在Co-B-Si体系中确定基础合金成分;然后添加少量的Nb对基础三元成分进行合金化以提高合金的玻璃形成能力。利用铜模吸铸法制备直径为3mm的合金棒,结果表明能够形成块体非晶的合金成分为(Co8B3-Si)100-xNbx(x=4～5at%),其中,Co8B3为密堆附半八面体的阿基米德反棱柱团簇结构。并且这些非晶成分可近似地用(团簇)1(胶粘原子)1模型表达,为(Co8B3)1M1(M=(Si,Nb)),即非晶成分由一个团簇连接一个胶粘原子组成,其中胶粘原子M为Si和Nb原子的组合。最后用Fe替代部分Co可进一步提高合金的玻璃形成能力,得到的Co-Fe-B-Si-Nb五元块体非晶合金具有很好的软磁性能,其饱和磁化强度(Ms)最大可达0.98T,矫顽力(Hc)低于6A/m。

Bulk metallic glass formations in Co-based Co（-Fe）-B-Si-Nb alloy systems are investigated using our cluster line approach in combination with minor alloying principle. Basic ternary alloy compositions in Co-B-Si system are first determined by cluster lines defined by linking special binary clusters to third elements. Then the basic ternary alloys are further alloyed with minor Nb to improve glass forming abilities. The alloy rods with a diameter of 3 mm are prepared by copper mould suction casting. The results indicate that bulk metallic glasses are formed in （Co8B3-Si）100-xNbx with 4-5% Nb, with Co8B3 being the most compact binary cluster. Furthermore, these bulk metallic glass compositions can be expressed approximately with a composition formula： （TM8B3）1M, M=（Si, Nb） or （Y, Nb）. Finally Fe substitution for Co further improves the glass-forming abilities. The Co-Fe-B-Si-Nb bulk metallic glasses exhibit good soft magnetic properties with high Ms, up to 0.98 T and low Hc, less than 6 A/m.