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通过磁悬浮熔炼-水冷铜模吸铸法制备了Cu46Zr44Al5Nb5块体非晶合金阶梯形试样,由X射线衍射(XRD),差示扫描量热仪(DSC)和万能试验机分别表征试样的结构、热力学和力学行为,研究其组织、热稳定性和力学性能与冷却速率的关系。结果表明,Cu46Zr44Al5Nb5合金具有较强的非晶形成能力和良好的热稳定性,其热力学行为表现出尺寸效应。熔体凝固冷却速率对试样尺寸变化敏感,随着试样尺寸的增加,冷却速度呈倍数递减、合金结构的无序度下降,原子排列向稳态转变,导致非晶合金的热稳定性降低。合金的玻璃转变温度不是定值,而是随冷却速度增加而升高,过冷液相区宽度ΔTx、约化玻璃转变温度Trg和晶化放热ΔH随直径的增加而降低,玻璃转变温度向低温漂移。随着直径的增加,冷却速度的降低,非晶合金的短程有序范围增大,最近邻原子间距减小,非晶合金结构的无序密堆性下降,原子排列向稳态转变,导致抗压强度降低,合金的断裂强度随试样直径的增大而减小。
The Cu46Zr44Al5Nb5 bulk amorphous alloy stepped samples were prepared by magnetic levitation-water cooled copper die-casting method. The structures of the samples were characterized by X-ray diffraction (XRD), differential scanning calorimeter (DSC) and universal testing machine , Thermodynamics and mechanical behavior, to study the relationship between its organization, thermal stability and mechanical properties and cooling rate. The results show that the Cu46Zr44Al5Nb5 alloy has strong amorphous formation ability and good thermal stability, and its thermodynamic behavior shows the size effect. The cooling rate of melt solidification is sensitive to the change of sample size. With the increase of sample size, the cooling rate decreases by a factor of a few, the disorder of the alloy structure decreases and the atomic arrangement changes to a steady state, resulting in the decrease of the thermal stability of the amorphous alloy . The glass transition temperature of the alloy is not constant, but increases with the increase of the cooling rate. The width ΔTx of the supercooled liquid region, the reduced glass transition temperature Trg and the heat of crystallization ΔH decrease with the increase of the diameter. The glass transition temperature Low temperature drift. With the increase of the diameter, the cooling rate decreases, the short range order of the amorphous alloy increases, the distance between the nearest neighbor decreases, the disorder of the amorphous alloy structure decreases, the atomic alignment shifts to steady state, The compressive strength decreases and the rupture strength of the alloy decreases with the increase of specimen diameter.