摘要
运用循环热膨胀法获得了块体非晶合金与其晶态合金的体膨胀差曲线△(dV(T)/V_0),由此定义出块体非晶合金的2个特征自由体积,即结构弛豫中释放出的自由体积△V_(f-sr)和玻璃转变中生成的自由体积△V_(f-gt).Fe(Er)-Cr-Mo-C-B系列块体非晶合金的实验结果表明:非晶合金的玻璃形成能力与其特征自由体积关系密切.临界尺寸D_c最大的非晶合金的△V_(f-gt)也最大;且D_c随△V_(f-sr)变化趋势明显,D_c^2或D_c可以拟合成△V_(f-sr)的负指数函数,回归系数高达0.998.
Many researches have demonstrated that the free volume have a great effect on the properties of bulk metallic glasses （BMGs）. For different BMGs, however, quantitative measurement of free volumes and analysis of properties of BMGs using the measurement results are still difficult. In this work, the two types of characteristic free volumes, the free volume released in structural relaxation,△Vf-sr and the free volume generated in glass transition, △Vf-gt are given from the △（dV（T）/V0） curve, where the △（dV（T）/V0） is the thermal expansion difference between amorphous and crystalline samples measured by a cyclic thermal dilation test. In a series of Fe-（Er）-Cr-Mo-C-B BMGs, it is found that the BMG with the largest critical diameter （De） has also the largest △Vf-gt, and Dc increases sensitively with the decrease of △Vf-sr. More impressively, Dc2 or Dc can be fitted with high regression coefficient of 0.998 by a negative exponential function of AM Hence, the characteristic free volume has a sensitive and close correlation with the glass forming ability of BMGs.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2012年第11期1329-1334,共6页
Acta Metallurgica Sinica
基金
深圳市科技计划项目CXB200903090012A
深圳市政府"人才驿站--双百计划"项目182资助~~
关键词
块体非晶合金
自由体积
结构弛豫
玻璃转变
玻璃形成能力
热膨胀
bulk metallic glass, free volume, structural relaxation, glass transition, glass-forming ability, thermal dilation
