CAJ | 학술논문

将固溶处理后的NZ31镁合金在不同温度及应变速率下进行拉伸实验，研究温度及应变速率对锯齿流变(Portevin-Le Chatelier效应)特征的影响。合金的锯齿流变行为出现在温度为150到250°C之间，在250°C时表现最剧烈，并且在晶粒内部可以发现特定取向的滑移带。随着温度的升高或应变速率的降低，锯齿流变类型由A型逐渐转变成 C 型。单个 A 型锯齿可划分为局部钉扎、完全钉扎和脱钉三个阶段。当温度升高或者应变速率降低时，溶质原子钉扎能力的增强会促进完全钉扎阶段的形成或者抑制脱钉阶段的发生，从而引起锯齿类型的转变。
장고용처리후적NZ31미합금재불동온도급응변속솔하진행랍신실험，연구온도급응변속솔대거치류변(Portevin-Le Chatelier효응)특정적영향。합금적거치류변행위출현재온도위150도250°C지간，재250°C시표현최극렬，병차재정립내부가이발현특정취향적활이대。수착온도적승고혹응변속솔적강저，거치류변류형유A형축점전변성 C 형。단개 A 형거치가화분위국부정찰、완전정찰화탈정삼개계단。당온도승고혹자응변속솔강저시，용질원자정찰능력적증강회촉진완전정찰계단적형성혹자억제탈정계단적발생，종이인기거치류형적전변。
The process of tensile test at different temperatures and strain rates was used to study the characteristics of serrated flow, i.e., Portevin-Le Chatelier effect (PLC), in NZ31 Mg alloy. The PLC effect in the tensile stress?strain curves was observed at the temperature range of 150?250 °C. Serrated flow during the deformation at 250 °C is prominent, and a lot of slip bands with a specific direction in each grain can be observed in the microstructure. The serration changes from type A to type C with the increase of temperature and the decrease of strain rate. One single serration of type A was described specifically by the processes of partial pinning, absolute pinning and unpinning. The enhancement of pinning ability at high temperature and low strain rate can promote the absolute pinning process and restrain the unpinning process, which explains the serration type transition.