低温热循环加速非晶合金剪切带在室温的结构弛豫
Accelerating structural relaxation of shear band at ambient conditions through cryogenic thermal-cycling
魏玉锋 1潘杰 2孙永昊 3李宁 1张诚 1汪卫华 3柳林1
作者信息
- 1. School of Materials Science and Engineering,State Key Lab for Materials Processing and Die & Mold Technology,Huazhong University of Science and Technology,Wuhan 430074,China
- 2. School of Materials Science and Engineering,State Key Lab for Materials Processing and Die & Mold Technology,Huazhong University of Science and Technology,Wuhan 430074,China;Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China
- 3. Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;Songshan Lake Materials Laboratory,Dongguan 523808,China
- 折叠
摘要
低温热循环是实现非晶合金结构回春的一种简单有效方法,但某些非晶合金在低温热循环处理后发生弛豫而不是回春.本研究通过在非晶合金中引入剪切带,在同一块样品上获得了不同区域初始能量不同的非晶合金,系统地研究了不同初始状态对低温热循环处理效果的影响.研究结果发现,在经过低温热循环处理后,同一试样中的剪切带发生结构弛豫,而基体发生结构回春.类似的双向变化趋势还可以从显微硬度、纳米压痕曲线以及压痕形状的变化上得到验证.经历了 100次低温热循环处理后,剪切带和基体的焓和硬度均收敛到一个平衡值.低温热循环能够加速剪切带的结构弛豫,实现了在低温热循环的上限温度上做长时间退火所达不到的状态.文中还采用自由体积模型对实验结果进行分析,阐明了非晶合金的初始状态影响其结构演化方向的机理.本研究为低温热循环处理非晶合金提供了新见解,阐明非晶合金初始状态在其焓变方向上的关键作用.
Abstract
Cryogenic thermal-cycling(CTC)is a promising method for the rejuvenation of metallic glasses(MGs).Al-though seemingly arbitrary,the direction of energy change in MGs following CTC sometimes results in relaxation rather than rejuvenation.By demonstrating enthalpy relaxation in a shear band(SB)and enthalpy rejuvenation in the metallic-glass matrix,the current work demonstrates that the initial state of the specimen matters.Micro-hardness,nano-in-dentation loading curves,and the shapes of indents all support the bidirectional trends.Notably,after subjecting the speci-men to 100 cryogenic thermal-cycles,the enthalpy and hard-ness tend to converge into an equilibrium value.It is discovered that CTC can accelerate the structural relaxation of SB at room temperature,a phenomenon that thermal an-nealing at the upper temperature(353 K)of CTC cannot achieve.Additionally,the experimental results have been elucidated by adapting the free-volume model.The work provides new insights into the functionalities of CTC and il-luminates the initial state of the metallic-glass sample upon reversing the direction of enthalpy change.
关键词
metallic glasses/cryogenic thermal-cycling/re-juvenation/relaxation/energy stateKey words
metallic glasses/cryogenic thermal-cycling/re-juvenation/relaxation/energy state引用本文复制引用
基金项目
国家自然科学基金(52022100)
国家自然科学基金(52192604)
国家自然科学基金(51971097)
国家自然科学基金(51971239)
国家自然科学基金(92263103)
湖北省重点研发计划(2022BAA023)
Basic Research Support Program of Huazhong University of Science and Technology(5003110121)
Young Elite Scientists Sponsorship Program by China Association for Science and Technology()
Analytical and Testing Center,Huazhong University of Science and Technology for technical assistance()
出版年
2024
NETL
NSTL
万方数据