Stress–strain behaviors of Ti-based bulk metallic glass and their nanostructures
Stress–strain behaviors of Ti-based bulk metallic glass and their nanostructures
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DOI：
10.1557/jmr.2007.0180
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发表时间：
2007-05
影响因子：
2.7
通讯作者：
T. Ohkubo;D. Nagahama;T. Mukai;K. Hono
中科院分区：
文献类型：
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作者：
T. Ohkubo;D. Nagahama;T. Mukai;K. Hono
研究了Cu模铸造法制备的Ti_（40）Zr_（25）Cu_（12）Ni_（33）Be_（20）大块非晶合金在不同熔体温度下的压缩应力-应变行为。塑性应变被认为是不同的熔体的温度和随后的退火条件敏感。为了了解塑性变化的起源，使用透射电子显微镜和激光辅助三维原子探针对微观结构进行了表征。在1273 K下铸造的完全非晶试样表现出0.6%的塑性应变，在573 K下等温退火后，塑性应变提高到1.3%。从1423 K铸造的样品显示出3.0%的塑性应变，从其中确认了具有约12%的体积分数的纳米晶体的存在。从较高的温度（1573 K）铸造的样品中含有较大比例的晶体，这表明有限的塑性应变。根据实验结果讨论了纳米晶体积分数对大块非晶塑性的影响。
We have investigated the compression stress–strain behaviors of Ti_40Zr_25Cu_12Ni_3Be_20 bulk metallic glasses prepared by Cu mold casting from various melt temperatures. Plastic strain was found to vary sensitively on the temperature of melts and subsequent annealing conditions. To understand the origin of the plasticity change, the microstructures were characterized using transmission electron microscopy and a laser-assisted three-dimensional atom probe. The fully amorphous sample cast from 1273 K showed 0.6% plastic strain, and it was enhanced to 1.3% after isothermal annealing at 573 K. The sample cast from 1423 K showed 3.0% plastic strain, from which the presence of nanocrystals with a volume fraction of about 12% was confirmed. The sample cast from a higher temperature (1573 K) contained a larger fraction of crystals, which showed limited plastic strain. The effect of the volume fraction of the nanocrystals on the plasticity of bulk metallic glasses is discussed based on the experimental results.