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利用四电极电阻法探索Cu36Zr48Al8Ag8非晶合金的晶化行为,以及熔体过热温度对其玻璃形成能力(GFA)和热稳定性的影响.结果显示:除文献中曾揭示的低温阶段晶化之外,该非晶合金在更高温度还发生第二阶段晶化.结合差示扫描量热仪(DSC)、X射线衍射仪(XRD)手段分析表明,第一阶段晶化产物为Cu10Zr7+AgZr亚稳相,它们在第二阶段晶化过程中转变为平衡相CuZr2+AlCu2Zr+CuAl2.当熔体过热度≥430 K时,所获非晶的热稳定性显著下降;并且第一阶段晶化行为发生改变,首先析出准晶.另外,随熔体过热度增大,其玻璃形成能力呈现先增强后减弱的趋势.就熔体过热对非晶热稳定性及玻璃形成能力的作用,本文从熔体结构均匀性和氧化程度两方面进行了分析讨论.
The effect of melt temperature on the glass forming ability (GFA) and thermal stability of Cu36Zr48Al8Ag8 amorphous alloy was investigated by means of four-electrode resistance method. The results showed that in addition to the low temperature crystallization , The second stage of crystallization also occurs at higher temperature.According to the analysis of differential scanning calorimetry (DSC) and X-ray diffraction (XRD), the first-stage crystallization product is Cu10Zr7 + AgZr In the second stage of crystallization, they are transformed into the equilibrium phase CuZr2 + AlCu2Zr + CuAl2. The thermal stability of the obtained amorphous alloy decreases significantly when the degree of superheat of the melt is over 430 K; and the crystallization behavior in the first stage In the meantime, as the degree of superheat of the melt increases, the glass forming ability tends to increase first and then weaken.As for the effect of melt overheating on the thermal stability and glass forming ability, Body structure uniformity and oxidation degree were analyzed and discussed.