摘要
研究Zr_(55)Cu_(30)Ni_(5)Al_(10)(摩尔分数,%)金属玻璃在深冷循环处理过程中的回春行为。实验发现,随着循环次数的增加,样品的回春程度更高,表现为更高的弛豫焓与更低的密度。回春程度经200次循环后逐渐饱和,这可能与非晶结构中有限的自由体积含量有关。同时,高循环次数下的样品硬度更低,塑性更好,这与其剪切转变区体积增大有关。此时,更低的剪切面形成能有利于多重剪切带的形成。此外,还发现自由体积含量与样品塑性应变及剪切转变区体积呈线性关系。分子动力学模拟结果还表明,在高冷速下回春程度高的样品会发生原子体积的饱和。
The rejuvenation behavior of a Zr_(55)Cu_(30)Ni_(5)Al_(10)(at.%)metallic glass upon deep cryogenic cycling treatment was investigated.The sample was rejuvenated to a larger extent with increasing cyclic number,resulting in a higher enthalpy of relaxation and a lower density.The rejuvenation seems to be saturated after 200 cycles,which may originate from the limited content of free volume in the amorphous structure.The sample subjected to a higher cyclic number showed a lower hardness and better plasticity due to a larger shear transformation zone(STZ)volume.In this case,a lower shear plane formation energy facilitates the generation of multiple shear bands.Furthermore,it is found that the content of free volume has linear relationship with the plastic strain and the STZ volume.The results from molecular dynamics simulation also demonstrates that the atomic volume saturates with a higher degree of rejuvenation at a higher cooling rate of the simulated sample.
作者
郭威
余圣
丁俊
吕书林
吴树森
赵觅
Wei GUO;Sheng YU;Jun DING;Shu-lin LÜ;Shu-sen WU;Mi ZHAO(State Key Lab of Materials Processing and Die&Mould Technology,School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;Research Institute of Huazhong University of Science and Technology in Shenzhen,Shenzhen 518057,China;Center for Alloy Innovation and Design,State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,Xi’an 710049,China;School of Aerospace Engineering,Huazhong University of Science and Technology,Wuhan 430074,China)
基金
supported by National Natural Science Foundation of China,China(No.52101138)
Natural Science Foundation of Hubei Province,China(No.2020CFB259)
Shenzhen Science and Technology Program,China(No.JCYJ20220530160813032)
State Key Lab of Advanced Metals and Materials,China(No.2020-Z01)
State Key Laboratory for Mechanical Behavior of Materials,China(No.20202205)
Guangdong Basic and Applied Basic Research Foundation,China(Nos.2020A1515110531,2021A1515111122)
State Key Laboratory of Materials Processing and Die&Mold Technology,Huazhong University of Science and Technology,China(No.P2021-021)
support from the National Natural Science Foundation of China(No.12004294)
National Youth Talents Program
support by Center for Alloy Innovation and Design(CAID)and HPC platform of Xi’an Jiaotong University。
关键词
金属玻璃
回春
深冷循环热处理
循环次数
塑性
metallic glass
rejuvenation
cryogenic cycling treatment
cyclic number
plasticity
