Ag元素添加对Cu-Zr-Al基金属玻璃纳米压痕行为的影响  

Effect of Adding Ag on the Nanoindentation Behavior of Cu-Zr-Al-Based Metallic Glass

作　　者：张倪侦 马昕迪 耿川 穆永坤 孙康[1] 贾延东 黄波 王刚[1] ZHANG Nizhen;MA Xindi;GENG Chuan;MU Yongkun;SUN Kang;JIA Yandong;HUANG Bo;WANG Gang(School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学材料科学与工程学院,上海200444

出　　处：《金属学报》2021年第4期567-574,共8页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目No.51925103。

摘　　要：采用铜模吸铸法制备得到不同Ag含量的Cu_(45)Zr_(45)Al_(10-x)Ag_(x)(x=1、2、3、5,原子分数,%)金属玻璃。利用纳米压痕技术系统地探讨了Ag元素添加对Cu-Zr-Al基金属玻璃纳米塑性变形行为的影响。借助经验方程拟合纳米压痕蠕变曲线求得应变速率敏感指数(m),进而计算出蠕变过程中的剪切转变区体积(Ω)。通过Kohlrausch-Williams-Watts方程拟合蠕变深度曲线,分析蠕变过程中的弛豫行为。结果表明,Ag含量增加导致KWW方程的扩展指数(β)增加。与此同时,Cu-Zr-Al基金属玻璃的硬度随微量Ag元素含量的增加而提高,并且在维持高硬度的基础上提高了塑性。本工作为理解金属玻璃热稳定性与力学性能的相关性奠定了基础。Metallic glasses(MGs) with a long-range disordered structure and without crystallographic defects have attracted great research attention. Owing to the disordered structure, MGs usually exhibit excellent physical and chemical properties, comprehensive mechanical performances, and high thermal stability. Minor doping of elements can effectively enhance the glass-forming ability of MGs and then seriously affect the yielding strength and plasticity. In this study, a family of Cu_(45)Zr_(45)Al_(10-x)Ag_(x)(x = 1, 2, 3, and 5, atomic fraction, %) MG with minor Ag-addition was prepared by suction casting. A nanoindentation test was used to investigate the influence of Ag content on the nanoplastic deformation behavior of the Cu-ZrAl-based MG. In terms of the empirical equation, the strain rate sensitivity index(m) was acquired to calculate the shear transformation zone volume during the nanoindentation creep process. Based on the Kohlrausch-Williams-Watts equation, the relaxation evolution was obtained. As Ag content approaches 5%, m attains its minimum, indicating that the creep resistance of the Cu-Zr-Al-based MG is the largest.The creep behavior of the system depends on the loading rate, i.e., the faster the loading rate, the lower the creep resistance. With an increase in the Ag content, the exponent stretch is increased, and the hardness of the Cu-Zr-Al-based MG was enhanced combined with an increased plasticity. This study presents the fundamental information of the relationship between the thermal dynamic and mechanical properties of the Cu-Zr-Al-based MG.

关 键 词：金属玻璃 蠕变深度 剪切转变区体积 弛豫 

分 类 号：TG139[一般工业技术—材料科学与工程]