摘要：Zr-Cu-Ti-Ni-Al合金因其优异的玻璃形成能力和廉价的成本具有巨大的应用前景。利用热处理引发液态相分离，从而调控锆基金属玻璃的内部结构，可以改进合金的性能。本论文通过使用高真空电弧熔炼炉制备Zr52.5Cu17.9Ni14.6Al10Ti5(BAM-11)合金，并在液-液相变的理论框架下，选取特定温度(430 ℃)，使用DSC分析仪对合金系进行热处理，制备纳米非晶合金，从而探索锆基块体非晶合金结构-性能的内在联系。实验采用广角X射线(X-ray diffraction，XRD)标定铸态合金及其热处理后所得纳米非晶合金的非晶本质，利用小角X射线散射(Small angle X-ray scattering，SAXS)观测所制备纳米非晶的纳米尺度非均匀性，利用电子显微镜(Transmission electron microscopy，TEM)观测其形貌。进行维氏硬度(Vickers hardness test，HV)测试和纳米压痕分析(Nanoindentation)比较金属玻璃和纳米非晶合金的力学性能差异。结果表明：通过在430 ℃保温600 s的等温退火热处理，在BAM-11合金中产生了直径最大为28 nm的新的非晶相，即制得了锆基纳米非晶合金；维氏硬度测试显示，该纳米非晶合金的显微硬度明显大于铸态BAM-11合金，且大于同成分的晶体；纳米压痕分析发现，该纳米非晶合金的表面纳米硬度变化规律与显微硬度变化规律相同，模量与同成分铸态合金模量基本相同；并未有证据显示铸态BAM-11合金经过此热处理后塑形下降了。

关键词  锆基非晶合金  热处理  制备  纳米非晶

毕业设计说明书外文摘要

Title  Preparation of Zirconium-based Nanostructured Glassy Alloys Based on Liquid-liquid Phase Transition

Abstract：Zr-Cu-Ti-Ni-Al alloy has great application prospect because of its excellent glass forming ability and low cost of production. The use of heat treatment to initiate liquid-liquid phase transition, which regulates the internal structure of zirconium-based metallic glass, can improve the performance of the alloy. In this paper, Zr52.5Cu17.9Ni14.6Al10Ti5 (BAM-11) alloy was prepared by using high vacuum arc melting furnace. The thermal analysis curves of the as-cast alloy were obtained by differential scanning calorimetry (DSC). Under the framework of liquid-liquid phase transformation, the specific temperature (430 ℃) was selected and the alloy system was heat treated by DSC analyzer to prepare nano-amorphous alloy to explore the intrinsic relationship between the structure and properties of zirconium-based bulk amorphous alloy.

The amorphous properties of the as-cast alloy and its nanostructured alloy after heat treatment were determined by wide-angle X-ray (XRD). Nanoscale heterogeneity of nanoglass was observed by small angle X-ray scattering (SAXS). The morphology was observed by electron microscopy (TEM). The Vickers hardness test (HV) and the nano-indentation analysis were used to compare the mechanical properties of metallic glass and nanostructured glassy alloys.

The results show that zirconium-based nano-glass was prepared by the isothermal annealing heat treatment at 600 ℃ for 600 s, and a new amorphous phase with maximum diameter of 28 nm was produced in BAM -11 alloy .The Vickers hardness test showed that the microhardness of the nanometer glass was significantly larger than that of the as-cast BAM-11 alloy and was also larger than that of the crystals with the same component；The nanoindentation analysis showed that the surface nanohardness of the nano-amorphous alloy changed as the microhardness did and the modulus of the nanoglass was the same with that of the as-cast alloy. No evidence for the plastic loss was found in the annealed alloy.

Keywords    Zirconium based amorphous alloy   Heat treatment Preparation   Nanostructured Alloy  

目   次

1  绪论 1

1.1 “透明的”玻璃与其早期研究 1

1.2  金属玻璃(非晶合金) 1