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Phase transition in the Zr_(60)Al_(15)Ni_(25) bulk metallic glass subjected to rolling at room temperature

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science china(Technological sciences) 2006年第6期49卷 655-662页

作者： YAN Zhijie1, 2, li jinfu1, zhou yaohe1 & WU Yanqing3.1. {3. key laboratory of metal matrix composites, school of materials science and engineering, Shanghai jiao tong university, Shanghai {13., china 2. school of materials science and engineering, Taiyuan university of science and Technology, Taiyuan 03.024, china 3. school of Environmental science and engineering, Shanghai jiao tong university, Shanghai {13., china state key laboratory of {3. matrix composites School of Materials Science engineering Shanghai Jiao Tong University Shanghai 200030 China school of materials science engineering Taiyuan University of Science Technology Taiyuan 030024 China school of Environmental science engineering Shanghai Jiao Tong University Shanghai 200030 China

The microstructure evolution of the Zr60Al15Ni25 metallic glass during rolling at room temperature is investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC); high-resolution transmission electron microscopy (HREM). The results show that the values of full width at half maximum (FWHM) of the XRD patterns; exothermic enthalpy ΔH of DSC plots do not monotonically change with the variation of deformation degrees . As is not large than 20%, the values of FWHM; ΔH are lower than that of the as-cast {3.. When reaches 3.%, the values of FWHM; ΔH become larger than that of the as-cast {3., while their values begin to decrease again as reaches about 85%. These results indicate that the reversible transitions between ordered; disordered atomic configurations occur during rolling, which is further verified by the HREM images. The reversible phase transition can be explained by the competition between the diffusion controlled reordering; shear-induced disordering during rolling.

关键词： metallic glasses, plastic deformation, phase transformations, shear bands.

Free-volume evolution of glassy Zr_(65)Al_(7.5)Ni_(10)Cu_(17.5) during inhomogeneous deformation

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Chinese science Bulletin 2007年第24期52卷 3443-3447页

作者： liU HuiBin li jinfut cao {3. zhou yaohe zhou yaohe state {3. laboratory of metal matrix composites School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai 200030 China

Free-volume evolutions of the as-cast and pre-annealed Zr65Al7.5Ni10Cu17.5 metallic glasses during cold-rolling were investigated using differential scanning calorimetry. As deformation degree increases, free volume in the glasses always increases first and then saturates above a critical strain, while the structure remains completely amorphous. The glass with less initial free volume possesses a higher increase rate of free-volume content during deformation, and as a result the free-volume contents of all the glasses approach each other at higher strains. Coalescence of free volume in shear bands into nanovoids is proposed to be responsible for the saturation of free-volume content at high strains.

关键词：金属眼镜退火塑胶变形自由体积

Crystallization Behavior of Zr_(55)Al_(10)Cu_(3.)Ni_5 Bulk metallic Glass Rolled at Room Temperature

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Journal of materials science & Technology 2010年第2期26卷 177-180页

作者： Yong Hu jinfu li Pengna Zhang yaohe {3. state key laboratory of {3. matrix composites School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai200240 China school of materials science and engineering Taiyuan University of Science and Technology Taiyuan 030024 China

Zr55Al10Cu3.Ni5 bulk metallic glass was rolled up to 95% in thickness reduction at room temperature, and the dependences of microstructure and thermal stability on the strain were investigated. It is revealed that phase transformations do not occur during the rolling, but the split of the crystallization peaks becomes more and more obvious with increasing thickness reduction. Analyses of the radial distribution functions and the pair correlation functions indicate that the rolling has enhanced the short-range order, which should be responsible for the enlarging split of the crystallization peaks.

关键词： metallic glass Plastic deformation Microstructure Thermal stability

Rolling-induced microstructure change in Zr_(65)Al_(7.5)Ni_(10)Cu_(12.5)Ag_5 bulk metallic glass

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Chinese science Bulletin 2011年第36期56卷 3948-3951页

作者： zhou Wei LU BinFeng KONG lingTi li jinfu zhou yaohe state key laboratory of {3. matrix composites School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai200240 China

The microstructures and free-volume evolutions of as-cast and pre-annealed Zr65Al7.5Ni10Cu12.5Ag5 bulk metallic glasses during rolling deformation have been investigated. No phase transformation is detected in the as-cast/rolled specimen. However,the structural stability of the glass against plastic deformation is worse after pre-annealing,indicated by nanocrystallization in preannealed/rolled specimens with large deformation degrees. Moreover,with increasing deformation degree,the free-volume content in a pre-annealed/rolled specimen increases at a lower average rate than that in an as-cast/rolled specimen.

关键词：大块金属玻璃微观结构诱导滚动自由体积塑性变形平均增长率轧制过程

液态金属深过冷快速凝固过程中初生固相的重熔

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金属学报 2018年第5期54卷 627-636页

作者：李金富周尧和上海交通大学材料科学与工程学院金属基复合材料国家重点实验室上海200240 上海交通大学材料科学与工程学院上海市激光制造与材料改性重点实验室上海200240

深过冷液态金属(合金)凝固时伴随有显著的温度再辉,初生固相因此不可避免地部分被重熔,从而影响到最终凝固组织形态。近年来,过冷熔体中晶体生长理论模型不断完善,使得定量分析初生固相重熔程度随过冷度的变化规律成为可能,本文即对这... 详细信息

深过冷液态金属(合金)凝固时伴随有显著的温度再辉,初生固相因此不可避免地部分被重熔,从而影响到最终凝固组织形态。近年来,过冷熔体中晶体生长理论模型不断完善,使得定量分析初生固相重熔程度随过冷度的变化规律成为可能,本文即对这方面的研究工作进展进行综述,并结合某些合金在不同过冷度下晶体生长行为及其凝固组织的实验结果,对典型非平衡凝固组织的形成机制进行阐述。

关键词：深过冷快速凝固固相重熔微观组织