原材料Ce的纯度对Ce-Ga-Cu系大块非晶合金形成能力的显著影响  

The impact of the Ce purity on glass forming ability in Ce-Ga-Cu bulk metallic glasses

作　　者：朱振西 陈成[1] 李宁[1] 张博[1] 

机构地区：[1]合肥工业大学材料科学与工程学院、安徽省功能材料与器件重点实验室,合肥230009

出　　处：《中国科学：物理学、力学、天文学》2015年第12期104-112,共9页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金资助项目(批准号:51322103;51171055)

摘　　要：本文通过使用不同纯度的原材料Ce制备Ce70GaxCu70-x(4≤x≤15)系大块非晶合金,系统研究了原材料纯度对合金玻璃形成能力(GFA)的影响.结果发现,相同的合金成分,Ce的纯度变化0.1%左右,能够引起非晶合金临界尺寸从1 mm到6–10 mm的变化.同时,Ce70GaxCu70-x(4≤x≤15)系的临界玻璃形成尺寸和Ga含量x之间的关系也随着Ce元素纯度的变化而显著变化.总体来看,与其他的Fe基和Zr基体系不同,低纯度的原材料有助于提高Ce-Ga-Cu系非晶合金的玻璃形成能力.本文还分析了合金的GFA和热力学参数之间的关系,发现晶化温度(Tx)越高,形成能力越好,这表明Ce基合金的形成能力与其抵抗晶化的能力密切相关.此外,实验结果也显示原材料杂质中的微量元素,能有效抑制Ce和CeCuGa3相的形成,从而导致合金GFA的提高.因此,本文结果有助于深入理解微量元素对玻璃形成能力的影响以及作用机制.The impact of the purity of raw material Ce on glass forming ability is systematically studied through preparing the Ce70GaxCu70-x（4≤x≤15） glassy alloys using different Ce raw materials with different purity. The results indicate that the GFA of the alloys is very sensitive to the Ce purity change and the critical size of the glassy sample would significantly change from 1 mm to 6-10 mm as the Ce purity changes by about 0.1% for the same alloy composition. Also, the correlation between the Ga content x and the critical diameter of the as-cast glassy rods changes obviously for different Ce bearing Ce70GaxCu70-x（4≤x≤15） alloys. Different from the results reported in other alloy systems like Fe- and Zr-based alloys, the GFA of the Ce-Ga-Cu alloys could be enhanced by using the low purity Ce raw material. The relationship between GFA and thermodynamic parameters is analyzed and found that there is a good correlation between the crystallization temperature and the glass-forming ability of these alloys and the better glass formers have higher the crystallization temperatures, which suggests that the GFA of Ce-based alloys closely related to the resistance ability of the supercooled liquid against crystalline. Furthermore, the impact of impurity elements of raw material Ce on GFA is investigated through annealing and crystallization experiments and the result indicates that low purity Ce raw materials can appreciably improve the formability of the present Ce-based bulk metallic glasses by suppressing the precipitation of Ce and CeCuGa3 phase due to the occurrence of phase competition. In general, the results indicate that the impurity of Ce base element substantially influences the stability of the Ce-based glass forming liquid, crystallization behaviors and thus GFA of the Ce-based glasses. Hence, the present work could help further understanding the effect of minor element addition on glass formation and its underlying mechanism in metallic glasses.

关 键 词：Ce-Ga-Cu系非晶合金 Ce纯度 形成能力 晶化行为 

分 类 号：TG139.8[一般工业技术—材料科学与工程]