Formation and mechanical properties of Cu–Hf–Al bulk glassy alloys with a large supercooled liquid region of over 90 K
Formation and mechanical properties of Cu–Hf–Al bulk glassy alloys with a large supercooled liquid region of over 90 K
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DOI：
10.1557/jmr.2003.0197
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发表时间：
2003-06
影响因子：
2.7
通讯作者：
A. Inoue;Wei Zhang-
中科院分区：
文献类型：
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作者：
A. Inoue;Wei Zhang-
在Cu-Hf-Al三元系中形成了具有大的过冷液相区和高机械强度的新型Cu基大块非晶合金。在Hf含量为40at%，Al含量为2.5%，Hf含量为37.5-50%，Al含量为5%时，在Al含量为7.5%时，Hf含量为45%，最大过冷液相区Δ T _x Cu_（50）Hf_（45）Al_5合金的T _x-T_g为91 K，Cu_（50）Hf_（42.5）Al_（7.5）和Cu_（52.5）Hf_（40）Al_（7.5）合金的最高约化玻璃转变温度为0.63。在50 K以上具有较大Δ Tx值的合金经铜模铸造可形成直径达3 mm的块状非晶合金棒，其压缩断裂强度为2260 ~ 2370 MPa，弹性模量为121 ~ 128 GPa，弹性伸长率为1.9%~ 2.0%，塑性伸长率为0.2%~ 0.6%。在Cu-Hf合金中加入2.5%~ 7.5%的Al对提高非晶形成能力和过冷液相的稳定性是非常有效的。这种有效性可以解释的基础上形成一个独特的玻璃态结构的概念，在特殊的多元合金与三个组件的规则。
New Cu-based bulk glassy alloys with large supercooled liquid regions and high mechanical strength were formed in Cu–Hf–Al ternary systems The large supercooled liquid region exceeding 70 K was obtained in the composition range of 40 at% Hf at 2.5% Al, 37.5–50% Hf at 5% Al, and 45% Hf at 7.5% Al. The largest supercooled liquid region Δ T _x(= T _x – T _g) was 91 K for Cu_50Hf_45Al_5 alloy, and the highest reduced glass-transition temperature was 0.63 for Cu_50Hf_42.5Al_7.5 and Cu_52.5Hf_40Al_7.5 alloys. The alloys with large Δ T _x values above 50 K were formed into bulk glassy rods with diameters up to 3 mm by copper mold casting, and the glassy alloy rods exhibited high compressive fracture strength of 2260 to 2370 MPa and Young's modulus of 121 to 128 GPa combined with elastic elongation of 1.9% to 2.0% and plastic elongation of 0.2% to 0.6%. No bulk glassy alloys were formed in the Cu–Hf binary system by copper mold casting, and, hence, the addition of 2.5% to 7.5% Al to Cu–Hf alloys was very effective for increasing glass-forming ability as well as the stabilization of supercooled liquid. The effectiveness can be interpreted on the basis of the concept of the formation of a unique glassy structure in special multicomponent alloys with the three component rules.