CAJ | 학술논문

利用三点弯曲的方法,研究了Zr-Cu-Al-Ni系块状金属玻璃的准静态弯曲变形和断裂行为.在室温下,准静态三点弯曲变形过程主要表现为弹性和塑性变形,塑性变形阶段没有出现加工硬化现象并且锯齿形流变不显著,挠度值最高为4.11 mm,显示出较好的塑性.SEM分析发现:弯曲试样受力状态复杂,表面剪切带并不是沿理论最大切应力方向扩展,弯曲试样内部压应力区的断口形貌与压缩实验断口相似,主要为脉状断口;不同的是在单向拉伸时呈现菊花状形貌,而在拉应力区,呈现出复杂的网状形貌,并发现大量的微孔和微裂纹,表明剪切带的形成与自由体积合并有关.
이용삼점만곡적방법,연구료Zr-Cu-Al-Ni계괴상금속파리적준정태만곡변형화단렬행위.재실온하,준정태삼점만곡변형과정주요표현위탄성화소성변형,소성변형계단몰유출현가공경화현상병차거치형류변불현저,뇨도치최고위4.11 mm,현시출교호적소성.SEM분석발현:만곡시양수력상태복잡,표면전절대병불시연이론최대절응력방향확전,만곡시양내부압응력구적단구형모여압축실험단구상사,주요위맥상단구;불동적시재단향랍신시정현국화상형모,이재랍응력구,정현출복잡적망상형모,병발현대량적미공화미렬문,표명전절대적형성여자유체적합병유관.
The deformation and fracture behavior under bending of bulk metallic glass Zr65 Cu15Ni10Al10 was studied using three-point bending machine and scanning electron microscopy (SEM) at room temperature.The results indicate that the samples experience elastic and plastic deformation process before fracture, and no obvious serrated rheological change and work hardening is found during plastic deformation. The biggest deflection value of specimens reaches 4.11 mm, which exhibits better plasticity. Shear bands do not propagate along the direction of theoretical maximum stress because of complex stress state. The fracture surface is typical vein- pattern in compressive stress regions, which is the same as fracture surface in compressive test. Complex reticular patterns are observed under different stress states in tension regions, and micro-scale voids and cracks exit along the shear bands, showing that the formation of shear bands is associated with free volume.