【作者】 刘映良； 曾楠； 张围； 李帅； 龙志林； 许福；

【Author】 FU Xu;NAN Zeng;YINGLIANG Liu;WEI Zhang;SHUAI Li;ZHILIN Long;College of Civil Engineering and Mechanics, Xiangtan University;

【机构】 湘潭大学土木工程与力学学院；

【摘要】 非晶合金的非晶态结构使其表现出独特的流变力学行为,对非晶合金的室温流变变形性质进行细致刻画有助于了解非晶合金的微观结构,进而揭示其变形机理。本文通过多级加-卸载模式下的纳米压痕蠕变实验,捕捉到了(La_0.5Ce_0.5)₆₅Al₁₀Co₂₅非晶合金在各阶段的蠕变变形,揭示了各阶段的变形性质。结果表明,非晶合金的蠕变包含可回复的黏弹性变形和不可回复的黏性流动部分,卸载后的蠕变回复为黏弹性变形部分;在第二次加载至蠕变荷载后,产生的流变变形主要为可回复的黏弹性变形,即二次加载时,材料未发现有明显的黏性流动变形;黏性流动部分的变形呈现非线性的性质,无法用单一的牛顿黏壶进行描述。更多还原

【Abstract】 Owing to the amorphous structure, metallic glass exhibit unique rheological behavior. Detailed characterization of the rheological properties of metallic glass is helpful to understand the microstructure of the amorphous alloy, so as to reveal the deformation mechanism. In this paper, the creep deformation of the(La_0.5Ce_0.5)₆₅Al₁₀Co₂₅ metallic glass at various stages was captured by nanoindentation creep test under multi-stage loading and unloading mode. Results show that the creep of metallic glass containing recoverable viscoelastic deformation and unrecoverable flow part. After unloading, the creep recovery deformation is viscoelastic. In the second loading stage while holding at the creep load, the generated rheological deformation is recoverable viscoelastic, namely during the secondary loading period, material is not found to have obvious viscous flow deformation. Furthermore, the viscous flow part is nonlinear, and cannot be described by single Newton dash-pot.更多还原