TiZrHfCuBe高熵非晶合金的纳米划痕力学行为  

Nanoscratching Mechanical Performance of the TiZrHfCuBe High-Entropy Metallic Glass

作　　者：杜银 李涛[1] 裴旭辉 周青[1] 王海丰[1] DU Yin;LI Tao;PEI Xuhui;ZHOU Qing;WANG Haifeng(Center of Advanced Lubrication and Seal Materials,State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072,China)

机构地区：[1]西北工业大学凝固技术国家重点实验室、先进润滑与密封材料研究中心,西安710072

出　　处：《金属学报》2024年第11期1451-1460,共10页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目No.51975474;中央高校基本科研业务费项目No.3102019JC001;凝固技术国家重点实验室(西北工业大学)自主研究课题项目No.2023-BJ-04。

摘　　要：对于高混合熵为高熵非晶合金带来的特殊结构和高热稳定性与其摩擦性能间内在联系的研究,可为开发具有优异摩擦磨损性能的高熵非晶合金提供新的设计思路。因此,本工作基于纳米压痕及划痕技术研究了TiZrHfCuBe高熵非晶合金在不同划动速率和不同加载速率下的纳米划痕行为,探究了高混合熵为其带来的特殊结构与其纳米摩擦学性能间的内在联系。结果表明:TiZrHfCuBe高熵非晶合金微观结构由缺陷较少的均匀刚性基体构成,不同区域的纳米压痕硬度均接近理论值的90%以上。在纳米划痕实验中,随着划动速率的增大,TiZrHfCuBe高熵非晶合金的刻划深度基本保持不变,但是残余划痕深度却逐渐减小。这归因于划动速率的增加迟滞了TiZrHfCuBe高熵非晶合金微观结构中剪切转变区的激活以及随后的剪切变形,从而导致划痕过程中的犁沟系数逐渐减小和残余深度的降低。在变力加载的纳米划痕实验中,随着加载力的增加,剪切转变区激活以及随后的剪切变形迟滞效应逐渐减小,导致塑性犁沟系数和划痕深度逐渐增大。As emerging advanced materials,metallic glasses demonstrate impressive high strength(approaching the theoretical strength of the material),fracture toughness,corrosion resistance,and thermoplastic-forming ability because of the absence of long-range atomic periodicity,making them potentially replace commercial materials for micro-electromechanical system applications.Although they possess high hardness,their structural instability upon wearing can cause structural relaxation or crystallization,leading to poor tribological behaviors.Inheriting the advantages of conventional metallic glasses and high-entropy alloys,high-entropy metallic glasses have recently attracted considerable attention.Compared with conventional metallic glasses,one prominent characteristic of high-entropy metallic glasses is higher structural thermostability,i.e.,reduced devitrification behavior upon heating,which directly affects its respondent behavior in the thermal-stress coupling field.However,the effect of the structural characteristics of high-entropy metallic glasses on wear resistance,which determines the service life of moving parts under actual working conditions,remains unknown.In this study,the nanoscratch behavior of the TiZrHfCuBe high-entropy metallic glass at different scratching and loading rates was investigated based on nanoindentation and nanoscratch technologies.Moreover,the relationship between the special structural characteristics due to high mixing entropy and the nanotribological properties of the TiZrHfCuBe high-entropy metallic glass was studied.The results show that the microstructure of the TiZrHfCuBe highentropy metallic glass is uniformly composed of a stiff matrix with sparse defects(i.e.,free volumes),and the nanohardness in different regions is close to 90%of the theoretical value.In the nanoscratch experiment,the scratching depth of the TiZrHfCuBe high-entropy metallic glass remained unchanged with increasing scratching rate,but the residual scratching depth gradually decreased.This is attributed to the fa

关 键 词：高熵非晶合金 微观结构 纳米划痕 犁沟系数 剪切变形 

分 类 号：TG113[金属学及工艺—物理冶金]