铁基块体非晶合金在纳米压痕过程中的蠕变行为研究  

Creep behavior of a Fe-based bulk amorphous alloy using nanoindentation

作　　者：彭建[1] 龙志林[1] 危洪清[1] 李乡安[1] 张志纯[1] 

机构地区：[1]湘潭大学土木工程与力学学院,湘潭411105

出　　处：《物理学报》2009年第6期4059-4065,共7页Acta Physica Sinica

基　　金：湖南省科技计划(批准号:2008FJ3095)资助的课题~~

摘　　要：利用纳米压痕技术研究了{[(Fe0.6Co0.4)0.75B0.2Si0.05]0.96Nb0.04}96Cr4铁基块体非晶合金的室温蠕变行为及不同的加载速率对该块体非晶合金蠕变变形的影响.{[(Fe0.6Co0.4)0.75B0.2Si0.05]0.96Nb0.04}96Cr4铁基块体非晶合金的室温蠕变变形与加载速率密切相关:在3—24mN/s加载速率下表现出显著的蠕变变形;随着加载速率的减小,蠕变变形逐渐变小,当加载速率为1mN/s和0.75mN/s时,蠕变变形基本消失.采用elastic-viscoelastic-viscous(EVEV)模型对该铁基块体非晶合金的蠕变变形进行了模拟.结果表明:EVEV模型能很好地模拟实验数据(相关系数R达到0.9392),并得到了与该块体非晶合金内部结构有关的蠕变柔量和延迟谱.基于室温蠕变速率敏感指数(m)的分析和纳米压痕的原子力显微镜(AFM)观测,细致讨论了{[(Fe0.6Co0.4)0.75B0.2Si0.05]0.96Nb0.04}96Cr4铁基块体非晶合金的室温蠕变机制.The creep behavior of a {[（Fe0.6Co0.4）0.75B0.2Si0.05]0.96Nb0.04}96Cr4 bulk amorphous alloy and effects of different loading rates on its creep deformation behavior were investigated using nanoindentation technique at room temperature. It is found that the creep deformation of this alloy is strongly dependent on the indentation loading rate： when the loading rate ranges from 3 to 24 mN/s, distinct ereep deformation occurs; but when the loading rate decreases to 1 mN/s or 0.75 mN/s, the creep deformation is completely suppressed. The creep deformation behavior of the{[（Fe0.6Co0.4）0.75B0.2Si0.05]0.96Nb0.04}96Cr4 bulk amorphous alloy was modeled using the elastic-viscoelastic-viscous （EVEV） model and a high correlation coefficient （R） of 0.9392 was obtained, implying that this creep behavior studied can be well described by the EVEV model. Based on the EVEV model, the ereep compliance and retardation spectrum, which are related to the interior strueture of the bulk amorphous alloy, were further calculated by the EVEV model. Finally, the ereep mechanism at room temperature was discussed in detail according to the analysis of the creep rate sensitivity index （m） as well as the observation on the morphology of indents using the atomic force microscope （AFM） .

关 键 词：块体非晶合金 蠕变 EVEV模型 蠕变速率敏感指数 

分 类 号：TG139.8[一般工业技术—材料科学与工程] TB938.2[金属学及工艺—合金]