Structural characterization and mechanical properties of nanocrystal-containing Cu–Ti-based bulk metallic glass-forming alloys
Structural characterization and mechanical properties of nanocrystal-containing Cu–Ti-based bulk metallic glass-forming alloys
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DOI：
10.1557/jmr.2007.0037
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发表时间：
2007-02
影响因子：
2.7
通讯作者：
Yufeng Sun;F. S. Li;S. Guan;Mingsheng Tang;C. Shek
中科院分区：
文献类型：
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作者：
Yufeng Sun;F. S. Li;S. Guan;Mingsheng Tang;C. Shek
采用铜模铸造法制备了直径为2 mm的圆柱形Cu42.5Ti41.5Ni7.5Zr2.5Hf5Si1大块金属玻璃。X射线衍射和差示扫描量热仪分析表明，该合金具有均匀的非晶态结构和较高的非晶形成能力。而透射电子显微镜的详细观察表明，一种尺寸约为20 nm的纳米晶稀疏分布在玻璃基质中。纳米束电子衍射实验表明，纳米晶具有面心立方晶体结构。室温压缩试验表明，该合金的断裂强度高达2250 Mpa，明显的塑性应变约为5.3%。纳米压痕测试表明，在0.5~10mN/min的加载速率范围内，铸态合金呈现明显的锯齿状流动。
Cylindrical Cu_42.5Ti_41.5Ni_7.5Zr_2.5Hf_5Si_1 bulk metallic glass with a diameter of 2 mm was fabricated by copper-mold casting. X-ray diffraction and differential scanning calorimetry analysis of the material showed that the alloy has a homogenous amorphous structure and high glass-forming ability. However, detailed observation by transmission electron microscopy revealed that a kind of nanocrystal with size of about 20 nm is sparsely distributed in the glass matrix. Nanobeam electron diffraction experiments indicated that the nanocrystal has a face-centered cubic crystalline structure. Room-temperature compression tests revealed that the alloy has a high fracture strength of 2250 MPa and obvious plastic strain of about 5.3%. Nanoindentation tests revealed that the as-cast alloy exhibits obviously serrated flow over a wide range of loading rate from 0.5 to 10 mN/min.