纳米晶化对锆基非晶合金动态压缩性能的影响  

Effect of Nano-Crystallization on Dynamic Compressive Property of Zr-Based Amorphous Alloy

作　　者：金辰日 杨素媛[1,2] 邓学元 王扬卫[1,2] 程兴旺[1,2] JIN Chenri;YANG Suyuan;DENG Xueyuan;WANG Yangwei;CHENG Xingwang(School of Materials Science and Engineering,Beijing Institute of Technology,Beijing 100081,China;National Key Laboratory of Science and Technology on Materials under Shock and Impact,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学材料学院,北京100081 [2]北京理工大学冲击环境材料技术重点实验室,北京100081

出　　处：《金属学报》2019年第12期1561-1568,共8页Acta Metallurgica Sinica

基　　金：国家部委项目No.2017-ZD-022~~

摘　　要：以铸态Zr-Cu-Ni-Al-Nb非晶合金为材料,通过控制退火保温时间获得部分纳米晶化非晶合金,并采用DSC、XRD、HRTEM、SEM、准静态及动态压缩等手段,研究了纳米晶化对非晶合金在不同应变率下的抗压强度以及断裂机制的影响。结果表明,随着退火保温时间的增加,锆基非晶合金内部纳米级晶化相的体积分数及尺寸均增加。退火态非晶合金的抗压强度随着保温时间增加先增大后减小;应变率变化也会影响其抗压强度,从1×10^-3s^-1增加到1×10^3s^-1时强度降低,继续增加到3×10^3s^-1时强度有所升高。不同程度的纳米晶化对非晶合金的断裂特征产生影响,随着晶化程度的增大,压缩试样的断口形貌从脉状花样向类准解理特征再向河流状花样转变。Zr-based amorphous alloys are characterized by high glass forming ability, high thermal stability and excellent mechanical properties. The amorphous alloys in thermodynamic metastable state have the tendency to change to metastable state with lower energy or even crystal structure in equilibrium state under certain temperature or pressure conditions. At present, few researches have been conducted on the mechanical behavior of partially crystallized Zr-Cu-Ni-Al-Nb amorphous alloys, especially the fracture behavior under dynamic loading. In this work, as-cast Zr-Cu-Ni-Al-Nb amorphous alloy was annealed to accomplish different levels of nano-crystallization by controlling holding time. DSC, XRD, HRTEM, SEM, quasi-static and dynamic compression tests were utilized to research the effect of nanocrystallization on compressive strength and fracture mechanism of Zr-based amorphous alloy under different strain rates. The results indicated that the volume fraction and size of nanoscale crystalline phase inside Zr-based amorphous alloy increased with the increasing of annealing holding time. The compressive strength of annealed Zr-based amorphous alloy increased first and then decreased with the increase ofholding time. The variation of strain rates also affected the compressive strength, which decreased when the strain rate increased from 1×10^-3s^-1 to 1×10^3s^-1, and increased when the strain rate continually increased to 3×10^3s^-1. Different degrees of nano-crystallization had an impact on the fracture characteristics of Zr-based amorphous alloy. As the degree of crystallization increased, the fracture morphology of compression samples changed from vein-like patterns to quasi-cleavage features and then to river patterns.

关 键 词：非晶合金 纳米晶化 动态压缩 断口形貌 

分 类 号：TG146.2[一般工业技术—材料科学与工程]