摘要
采用Gleeble-1500热模拟试验机对2A12铝合金进行了单向热压缩变形试验,研究了其在变形温度为320~480℃,应变速率为0.0003~1 s^(-1)条件下的热变形行为,建立了基于动态材料模型的功率耗散效率因子η图,并对热加工图进行了组织验证。结果表明:合金的流变应力随着变形温度的升高和应变速率的降低而降低,在高温区变形机制为动态回复,在低温区变形机制为动态再结晶,主要与合金变形过程中的析出相有关;随着应变量的增大,峰区的η值逐渐升高;当真应变为1.2时,在变形温度为440℃,应变速率为0.1 s^(-1)时,η达到峰值且为48%,合金发生了动态再结晶,晶粒细化且无内裂纹。该结果为2A12铝合金实际热加工工艺的优化提供了理论依据。
Uniaxial hot compression deformation experiment of 2A12 alloy was performed on Gleeble-1500 thermal simulator under the conditions of deformation temperatures of 320-480 ℃ and strain rates of 0. 0003-1 s^-1,and the hot deformation behavior was investigated.The maps of power dissipation efficiency η which based on dynamic material model（ DMM） were established and the microstructure validation of processing maps was also done. The results show that the flow stress decreases with the deformation temperature increasing and strain rate decreasing. The deformation mechanism in the higher temperature zones is dynamic recovery and it is dynamic recrystallization in the lower temperature zones,which is related to the precipitates resulting from the hot deformation process. The values of η in the peak zones gradually increase with the strain increasing. When the true strain is 1. 2,the alloy has peak η of 48% at 440 ℃ and 0. 1 s^-1,which is corresponding to dynamic recrystallization,grain refinement and without inner cracks. The above results can be used as a theoretical reference for the optimization of actual hot working processing of 2A12 alloy.
出处
《金属热处理》
CAS
CSCD
北大核心
2017年第4期12-17,共6页
Heat Treatment of Metals
基金
国防技术基础科研项目(JSJC2013204B403)
关键词
2A12铝合金
热压缩
流变应力
加工图
动态再结晶
2A12 aluminum alloy
hot compression
flow stress
processing map
dynamic recrystallization
