(1. 兰州理工大学 甘肃省有色金属新材料省部共建国家重点实验室，兰州 730050；2. 兰州理工大学 有色金属合金省部共建教育部重点实验室，兰州 730050)
摘 要: 在玻璃转变温度以下选择350、400、475及600 K进行1 h的等温退火，用纳米压痕仪、扫描电镜等研究Cu基块状非晶晶化过程的力学性能及变形。Cu基块状非晶在纳米压头作用下体现弹−塑性变形方式，载荷—位移曲线和压痕周边多重剪切带的特征证明了塑性变形的存在。350 K退火试样具有较大的压痕硬度HV和弹性模量E值及较小的塑性变形量dn值；400 K退火后，HV和E值显著减小，dn值明显增大；475 K退火后，有少量晶体相析出，但合金以非晶的特性为主，HV和E值继续减小，dn值继续增大；600 K退火后，晶体相进一步长大和析出，其固溶强化和弥散强化使合金的HV和E值有所增加，dn值略有减小。对塑性变形机理进行了初步分析。
关键字: Cu基块状非晶；晶化；纳米压痕；变形；力学性能
（1. State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials, Lanzhou University of Technology, Lanzhou 730050, China; 2. Key Laboratory of Non-ferrous Metal Alloys, Ministry of Education, Lanzhou University of Technology, Lanzhou 73005, China）
Abstract:350, 400, 475 and 600 K below glass transition temperature were chosen for isothermal annealing for 1 h. Mechanical properties and deformation of Cu-based bulk metallic glasses(BMGs) during crystallization were studied with nanoindentation instrument and scanning electron microscope(SEM). The results indicate Cu-based BMGs deform in elastic-plastic modes under a nanoindenter. Load-displacement curve and multiple shear bands around a nanoindenter confirm the existence of plastic deformation. The sample annealed at 350 K exhibits higher microhardness(HV), elastic modulus(E), and lower plastic deformation(dn); HV and E values decrease and dn value increases significantly at 400 K; crystal phases exist at 475 K, but the major properties of the alloy is amorphous. HV and E values reduce and dn value increases continually; with growth and precipitation of crystal phases at 600 K, solid solution strengthening and dispersion strengthening of the phases slightly augment HV and E values, and reduce dn value. The plastic deformation mechanism during crystallization is preliminarily analyzed.
Key words: Cu-based bulk metallic glass; crystallization; nanoindentation; deformation; mechanical properties
