供应态2B70铝合金超塑性试验研究  

Experimental study on superplasticity of commercial 2B70 aluminum alloy

作　　者：刘鸣[1] 郭鸿镇[1] 王晓燕[1] 姚泽坤[1] 阙基蓉 方清万 

机构地区：[1]西北工业大学材料学院,陕西西安710072 [2]西南铝业(集团)有限责任公司,重庆401326

出　　处：《轻合金加工技术》2008年第8期41-44,共4页Light Alloy Fabrication Technology

摘　　要：试验研究了供应态2B70铝合金经普通退火处理后在不同变形工艺下的超塑性变化规律。结果表明：采用3.3×10^-4s^-1的初始应变速率,在360℃～490℃的拉伸温度范围内2B70铝合金具有一定的超塑性。450℃为合金的最佳超塑性拉伸温度,3.3×10^-4s^-1为最佳初始应变速率,在最佳超塑性条件下合金的最大伸长率达到193.3%,流动应力为13.94 MPa。在超塑性拉伸过程中,由于不断发生动态回复及再结晶,晶粒趋于明显细化和等轴化。合金的超塑性变形是以晶界滑移为主的变形机制,在较低拉伸温度及较高初始应变速率下晶界滑移痕迹较少,表现出明显的晶间断裂特征。The superplastic deformation law of commercial 2B70 aluminum alloy via normal annealing under different deforming craft was studied, The results revealed that： the tensile specimens all present superplasticity at the initial strain rate 3.3 × 10^-4 s^-1 and the range of temperature from 360℃ to 490℃. The optimal superplastic deformation condition is at 450℃ and 3.3 × 10^-4 s^-1 , on which the highest elongation is 193.3% and the flow stress is only 13.94 MPa. The dynamic recovery and recrystallization were occurred continuously during the superplastic deformation so the crystalline grain became refining and equiaxial obviously, grain boundary sliding is the primary deformation mechanism. The trace of grain boundary sliding is quiet little and the character of intergranular fracture is apparent when deforming under low temperature and high initial strain rate.

关 键 词：2B70铝合金 超塑性 动态再结晶 晶界滑移 

分 类 号：TG146.21[一般工业技术—材料科学与工程]