B_4C_P/2009Al复合材料动态再结晶临界条件  

Critical Conditions of Dynamic Recrystallization for B_4C_P/2009Al Composite

作　　者：李德富[1] 刘生璞 郭胜利[1] LI De-fu;LIU Sheng-pu;GUO Sheng-li(General Research Institute of Non-ferrous Metals, Beijing 100088, China)

机构地区：[1]北京有色金属研究总院,北京100088

出　　处：《精密成形工程》2018年第2期67-73,共7页Journal of Netshape Forming Engineering

基　　金：国家自然科学基金(52105028)

摘　　要：目的研究B_4C_P/2009Al复合材料的热变形流变行为,确定B_4C_P/2009Al复合材料发生动态再结晶的临界条件。方法采用Gleeble-1500热模拟机对体积分数为25%的B_4C_P/2009Al复合材料进行热压缩试验,热压缩温度为300~500℃,应变速率为0.001~1 s^(-1),并建立热变形本构方程。基于加工硬化率曲线(θ-σ),获得动态再结晶临界条件。结果 B_4C_P/2009Al复合材料的流变应力随温度的升高和应变速率的降低而降低。临界应力(σ_c)与峰值应力(σ_p)存在线性关系:σ_c=0.2992σ_p+22.4698,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:εc=1.35×10^(-3)Z^(0.047 39)。结论 B_4C_P/2009Al复合材料的流变应力曲线以动态再结晶软化机制为主要特征,B_4C增强颗粒的加入促进了复合材料的动态再结晶。The paper aims to study hot deformation behaviors of B4CP/2009Al composite and confirm the critical conditions of its dynamic recrystallization.The hot compression tests of25%B4CP/2009Al composite were conducted at deformation temperature of300~500℃and strain rate of0.001~1s?1on a Gleeble-1500thermal simulator.The hot deformation constitutive equation was established.Based on the strain hardening rate curves(θ-σ),the critical conditions of dynamic recrystallization were identified.The flow stress-strain of B4CP/2009Al composite decreased with the increase of temperature and the decrease of strain rate.There was a liner relationship betweenσc andσp:σc=0.2992σp+22.4698,and the Zener-Hollomon parameter was introduced to describe the effect of deformation conditions on critical conditions:εc=1.35×10?3Z0.04739.The flow stress-strain curve of B4CP/2009Al composite shows the main characteristic of dynamic recrystallization and the addition of B4C particles promotes the dynamic recrystallization process of the composite.

关 键 词：B4CP/2009Al复合材料 动态再结晶 临界条件 加工硬化率 

分 类 号：TB333[一般工业技术—材料科学与工程]