Shaping of Bulk Metallic Glasses by Simultaneous Application of Electrical Current and Low Stress
Shaping of Bulk Metallic Glasses by Simultaneous Application of Electrical Current and Low Stress
复制标题
同时施加电流和低应力对块状金属玻璃进行成型
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
W. Botta
中科院分区：
文献类型：
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作者：
A. Yavari;M. D. Oliveira;W. Botta
利用块体金属玻璃（BMG）的固有材料特性，即比良导体高两个数量级的导电率和牛顿粘性流动的变形能力，开发了一种新的用于BMG成形、连接和雕刻的机电工艺。块体金属玻璃的玻璃化转变温度Tg和结晶温度Tx之间的液态过冷区越宽，新工艺越容易应用。在此范围内，过冷液体以准牛顿方式变形，允许在低粘度范围内热机械成形，如氧化物玻璃。新的机电加工技术已被用于在低施加应力下经济和快速成形，消除了炉的热质量和加热变形模具的需要。工艺参数可适应于玻璃态的完全保持，或者当需要时，可适应于合适的组成，可适应于在连接或成形操作期间的纳米烧结。
Using the intrinsic materials properties of bulk metallic glasses (BMG), namely electrical resistivities two orders of magnitude higher than good conductors and a Newtonian viscous-flow regime of deformability, a new electromechanical process has been developed for shaping, joining and engraving of BMGs. The wider the liquid supercooled region between the glass transition temperature T g and the crystallisation temperature T x of the bulk metallic glass, the easier the application of the new process. In this range, the undercooled liquid deforms in a quasi-Newtonian way, allowing thermomechanical shaping in the low viscosity range as for oxide glasses. The new electromechanical processing technology has been used for economical and rapid shaping at low applied stresses by eliminating the thermal mass of the furnace and the need to heat the deformation dies. The process parameters are adaptable for the full maintenance of the glassy state or when desired, for appropriate compositions, for nanocrystallisation during the joining or shaping operation.