【作者】 何国伟；

【导师】 李工；

【作者基本信息】 燕山大学 ， 材料学， 2011， 硕士

【摘要】 本文选用Zr₅7Al₁5Co₂0Ag₈和Zr57Al15Co28两种非晶合金材料,采用X射线衍射（XRD）和差示扫描量热分析（DSC）实验表征了其非晶结构以及Ag的添加对合金结构和性能参数的影响。DSC实验结果表明:在20 K/min加热速率下,Zr₅7Al₁5Co₂0Ag₈非晶合金的第一晶化温度为787.5 K,Zr57Al15Co20非晶合金的第一晶化温度为806.4 K。利用Kissinger关系研究了Zr₅7Al₁5Co₂0Ag₈和Zr57Al15Co28非晶合金的晶化动力学行为,其晶化激活能分别为521.5 KJ/mol和375.9 KJ/mol。利用纳米压痕技术分析对比了两者的弹性性能以及加载速率对弹性模量、纳米硬度等参数的影响。最大载荷为5000μN时,Zr57Al15Co28的加载和卸载曲线斜率均比Zr57Al15Co20Ag8非晶合金的大,表明前者的弹性性能较后者良好,即由于贵金属Ag的添加使得Zr57Al15Co20Ag8非晶合金的弹性性能减弱。利用高压同步辐射技术对Zr57Al15Co20Ag8和Zr57Al15Co28在高压下进行压缩性能研究得到了非晶合金的状态方程分别为:-ΔV₀ / V₀ =-0.06959+0.00971P-1.16447×10_-4P₂+4.70907×10_-6P₃ -ΔV₀ / V₀ =-0.10844+0.02143P-6.90900×10_-4P₂+8.02256×10_-6P₃两者的B（体弹模量）分别为102.98 GPa和46.66 GPa。利用六面顶高压技术在300℃、0-5 GPa压力条件下,研究了压力对Zr₅7Al₁5Co₂0Ag₈非晶合金的晶化和相变过程的影响;利用Ozawa关系式分析了高压退火处理对Zr₅7Al₁5Co₂0Ag₈非晶合金动力学的影响。实验结果表明:晶化激活能与压力密切相关;经过高压退火处理后非晶合金的纳米硬度和弹性模量平均值有增大的趋势;其中纳米硬度值分布较为分散而弹性模量数值较为集中。更多还原

【Abstract】 In this thesis, Zr₅7Al₁5Co₂0Ag₈ and Zr57Al15Co28 metallic glasses were selected, the structures of both alloys were detected and compared by the XRD and the DSC measurements. The addition of the Ag has large impact on the structure and the performance parameters of the Zr57Al15Co28. The results show that the first crystallization temperature of Zr₅7Al₁5Co₂0Ag₈ is about 787.5 K which is ahead of 806.4 K of the Zr57Al15Co28. We investigated the crystallization kinetics of both metallic glasses through Kissinger equation, which show that the crystallization activation energy of the Zr₅7Al₁5Co₂0Ag₈ and the Zr57Al15Co28 is about 521.5 KJ/mol, 375.9 KJ/mol respectively.Instrumented Nano-indentation experiments that were conducted to compare the elastic properities of both metallic glasses and to analyse the effect of loading rate on elastic modulus and hardness. The results show that the gradient of the loading and unloading curve of Zr57Al15Co28 under 5000μN is steeper than Zr57Al15Co20Ag8, which is a distinct symbol that the elastic properity of Zr57Al15Co28 is superior than Zr57Al15Co20Ag8. The addition of Ag give rise to the enhancement of plastic deformation and the weakness of elastic properity of Zr₅7Al₁5Co₂0Ag₈ metallic glass.Utilizing the high pressure synchronization radiation technique to study the compressibility of the Zr₅7Al₁5Co₂0Ag₈ and the Zr57Al15Co28, we gained the equation of the state accurately as follows: -ΔV₀ / V₀ =-0.06959+0.00971P-1.16447×10_-4P₂+4.70907×10_-6P₃ -ΔV₀ / V₀ =-0.10844+0.02143P-6.90900×10_-4P₂+8.02256×10_-6P₃The corresponding B （elastic modulus） of Zr₅7Al₁5Co₂0Ag₈ and the Zr57Al15Co28 are 102.98 GPa and 46.66 GPa respectively.High pressure experiments were performed for Zr₅7Al₁5Co₂0Ag₈ alloys by the cubic anvil high pressure apparatus under 300℃to investigate the influence of pressure on crystallization and phase transformation course of Zr₅7Al₁5Co₂0Ag₈ metallic glass; The Ozawa curve is fitted linearly to investigate the annealing effect under high pressure on kinetics behavior of the Zr₅7Al₁5Co₂0Ag₈ metallic glass. The final data indicate that the crystallization activation energy have great relation with high pressure; The average hardness and elastic modulus is developing towards the higher values while the hardness values are more dispersive than elastic modulus values.更多还原