摘要
通过等温热压缩实验对25%B_4C_p/6061Al(体积分数)复合材料的热变形行为和动态再结晶临界条件进行了研究,采用的温度范围为350~500℃,应变速率范围为0.001~1 s^(-1)。应力-应变曲线显示动态再结晶是复合材料热变形过程中主要的软化机制,并采用峰值应力构建了基于Arrhenius形式的本构方程。基于加工硬化率曲线,求解了表示动态再结晶发生的临界应变与临界应力值。结果表明,临界应力与峰值应力存在线性关系:σ_c=0.8374σ_p–0.33708。此外,引入Zener-Hollomon参数描述变形条件对临界条件的影响,得到临界应变与Z参数的关系:ε_c=2.39×10^(-4)Z^(0.11022)。最后,通过θ-ε曲线得到了复合材料完成动态再结晶时的稳态应变,并绘制了动态再结晶图。
Flow behavior and dynamic recrystallization(DRX) critical conditions of 25vol% B_4C_p/6061Al composite were investigated by isothermal compression tests at temperatures ranging from 350 to 500 °C with strain rates of 0.001 to 1 s^(-1). The stress-strain curves show that DRX is the main softening mechanism of the composite, and an Arrhenius-type equation is developed using peak stress. Based on the strain hardening rate curves(θ-σ), the critical strain(ε_c) and critical stress(σ_c) are identified to express the initiation of DRX. The results indicate that there is a liner relationship between σc and σ_p:σ_c=0.8374σ_p–0.33708. The Zener-Hollomon parameter was also introduced to describe the effect of deformation conditions on critical conditions: ε_c=2.39×10^(-4)Z^(0.11022). In addition, the steady-state strains(ε_(ss)) were determined by the θ-ε curves, and then the DRX diagram was established.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2017年第7期1815-1820,共6页
Rare Metal Materials and Engineering
基金
National Natural Science Foundation of China(51205028)