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Cu-Zr基非晶合金的玻璃形成能力与原材料中的氧和其他非金属杂质非常敏感。采用低纯材料通过铜模吸铸法制备Cu45Zr47Al8非晶合金,研究杂质对Cu-Zr基非晶合金玻璃形成能力和热稳定性的影响。用X射线衍射(XRD),透射电子显微镜(TEM)和能谱仪(EDS)分析合金组织结构及差示扫描量热法(DSC)分析合金的热稳定性。实验结果表明:低纯材料制备出临界直径7 mm以上的非晶合金。由于低纯材料中的一些微量杂质元素被认为合金化元素,适量的杂质元素没有导致合金的玻璃形成能力降低;而过量的氧和其他杂质元素导致非均匀形核并随之发生结晶,合金的玻璃形成能力明显地降低。低纯材料制备的合金的ΔTx和晶化激活能均高于高纯原料制备的;并基于Kissinger方法所构建的开始晶化曲线表明低纯材料制备的合金的晶化孕育期更长,说明低纯材料制备的合金具有更强的热稳定性。低纯材料成功制备出大块Cu-Zr基非晶合金,为促进非晶合金的商业应用有重要意义。
The glass-forming ability of Cu-Zr-based amorphous alloys is very sensitive to oxygen and other non-metallic impurities in raw materials. Cu45Zr47Al8 amorphous alloy was prepared by copper mold suction casting using low-purity materials, and the influence of impurities on the glass forming ability and thermal stability of Cu-Zr-based amorphous alloy was studied. The thermal stability of the alloy was analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive spectrometer (EDS) analysis of the alloy structure and differential scanning calorimetry (DSC). The experimental results show that the low-purity materials prepared amorphous alloys with a critical diameter of 7 mm or more. Since some trace impurities in low-purity materials are considered as alloying elements, the proper amount of impurity elements does not lead to a decrease in the glass-forming ability of the alloy; while excessive amounts of oxygen and other impurity elements cause heterogeneous nucleation and subsequent crystallization, Glass formation ability is significantly reduced. The ΔTx and crystallization activation energies of alloys prepared from low-purity materials are higher than that from high-purity materials. The onset crystallization curve based on Kissinger method shows that the crystallization period of the alloys prepared from low-purity materials is longer, indicating that the low Alloys made from pure materials have greater thermal stability. Low-purity materials successfully prepared bulk Cu-Zr-based amorphous alloys, to promote the commercial application of amorphous alloys of great significance.