Ti_(20)Zr_(20)Hf_(20)Cu_(20)Be_(20)高熵非晶合金应力弛豫行为研究  

Stress Relaxation Behavior of Ti_(20)Zr_(20)Hf_(20)Cu_(20)Be_(20)High-Entropy Metallic Glass

作　　者：陈长玖 许锐 张金勇 张平[1] 何业增 沈宝龙[1,2] Chen Changjiu;Xu Rui;Zhang Jinyong;Zhang Ping;He Yezeng;Shen Baolong(School of Materials Science and Physics,China University of Mining and Technology,Xuzhou 221116,China;School of Materials Science and Engineering,Southeast University,Nanjing 211189,China)

机构地区：[1]中国矿业大学材料与物理学院,江苏徐州221116 [2]东南大学材料科学与工程学院,江苏南京211189

出　　处：《稀有金属材料与工程》2021年第12期4381-4387,共7页Rare Metal Materials and Engineering

基　　金：江苏省自然科学基金(BK20180659);中央高校基本科研业务费专项资金(2018QNA05);江苏省双创团队、双创博士项目。

摘　　要：采用应力分析方法对Ti_(20)Zr_(20)Hf_(20)Cu_(20)Be_(20)高熵非晶合金条带进行了研究,旨在揭示高熵非晶合金应力弛豫行为。通过分析其在恒定应变下较宽时间窗口和温度窗口内的应力衰减过程,发现在低于T;的玻璃态下,高熵非晶合金中存在着弛豫解耦现象,分别是慢弛豫和快弛豫过程。其中慢弛豫呈现扩展指数衰减模式,弛豫时间存在对温度的Arrhenius动力学依赖关系,与长程原子重排运动有关,快弛豫过程对应于微观局部内应力的逐步消散过程。不论该高熵非晶合金变形处于弹性阶段还是发生了屈服,应力弛豫过程受应变的影响都较小。本研究揭示了高熵非晶合金中新的弛豫解耦现象和与之相关的独特动力学机制,拓宽了对高熵非晶合金弛豫动力学过程以及其本征特性的认知。The mechanical relaxation behavior of Ti_(20)Zr_(20)Hf_(20)Cu_(20)Be_(20)high-entropy metallic glass(HE-MG)was investigated by static stress relaxation analysis.With a constant strain,the stress relaxation process was analyzed in a wide time window and temperature range.A decoupling of the relaxation into a two-step(slow relaxation and fast relaxation)was found in the glass state below T;.The slow relaxation process exhibits a stretched decay and a significant Arrhenius dependence on the temperature.The relaxation time decreases sharply with the increase of the temperature,which may relate to the long-range atomic rearrangements at larger scales.The fast relaxation relates to the atomic scale internal stress dissipation.In addition,the strain has no distinct influence on the stress relaxation process,whether high-entropy metallic glass is deformed in the elastic stage or yielded.This study reveals the decoupling phenomenon and the related unique dynamics relaxation mechanism in high-entropy metallic glass,which will enhance our understanding of the mechanical relaxation behavior and intrinsic characteristics of high-entropy metallic glasses.

关 键 词：高熵非晶合金 应力弛豫 弛豫解耦 KWW方程 弛豫时间 

分 类 号：TG139.8[一般工业技术—材料科学与工程]