均匀化退火对Al-1Mn-1Mg合金高温压缩流变应力的影响  

Influence of homogenization on flow stress of Al-1Mn-1Mg alloy during hot compression deformation

作　　者：陈永禄[1] 傅高升[2] 陈文哲[1] 王火生[1] 

机构地区：[1]福建工程学院材料科学与工程系,福建福州350014 [2]福建交通职业技术学院,福建福州350007

出　　处：《材料热处理学报》2008年第2期103-107,共5页Transactions of Materials and Heat Treatment

基　　金：福建省教育厅重点资助项目(JA04251);福建省科技厅青年人才项目(2006F3006);福建省科技厅重大专项(2006HZ0002-1)

摘　　要：采用热模拟试验机研究了均匀化退火对经高效铝熔体综合处理的Al-1Mn-1Mg合金高温变形等温压缩流变应力的影响（变形温度573～773K、应变速率0.01～10.0s^-1）。结果表明：该合金在均匀化退火前后均易发生动态软化并最终进入稳态流变阶段,属负温度敏感性和正应变速率敏感性材料;在T=673K、ε^·≥10.0s^-1的热变形条件下,均发生了不连续动态再结晶;均匀化退火降低了铸态合金的流变应力,高温低速大应变量的热变形减弱了均匀化退火对热变形流变应力的影响,流变应力水平趋于一致;在变形温度范围内,均匀化退火可促进该合金发生动态软化,增强热变形能力,但随着均匀化温度的提高,动态软化趋势减弱。经723K×12h均匀化退火后,Al-1Mn-1Mg合金具有较低的热变形激活能（197.28 kJ·mol^-1）,易进行热变形。The isothermal compression tests at elevated temperature for Al-1Mn-1Mg alloy prepared by high-efficient melt-treatment were conducted on a dynamic thermal/mechanical simulation testing machine.Influence of homogenization on flow stress of the Al-1Mn-1Mg alloy was investigated.The results show that the alloy before and after homogenization exhibits negative temperature sensitivity and positive strain rate sensitivity and the alloy favors to dynamic softening and the flow stress reaches steady gradually in the end.Discontinuous dynamic recrystallization occurrs under the hot deformation condition of T=673K and ε^·≥10.0s^-1.The flow stress of as-cast alloy decreases by homogenization and the effect of homogenization on flow stress can be induced when the compression is carried out at higher temperature,lower strain rate or largr strain and thus makes the flow stress tend to be the same level.Homogenization can promote the dynamic softening and hot deformation ability of the alloy in the range of the experimental deformation temperatures,but the trend of dynamic softening is reduced with increasing the homogenization temperature.The alloy homogenized at 723K for 12hours with lower activation energy（197.28kJ·mol^-1）exhibits good hot deformation performance.

关 键 词：均匀化退火 Al-1Mn-1Mg合金 高温压缩变形 流变应力 

分 类 号：TG146.2[一般工业技术—材料科学与工程] TG156.2[金属学及工艺—金属材料]