高强韧Al-Zn-Mg-Cu合金的热加工图及组织演变  

Hot Processing Maps and Microstructure Evolution of the High Strength and Toughness Al-Zn-Mg-Cu Alloy

作　　者：徐国富[1,2] 苏武森 肖丹[1] 彭小燕[1] 

机构地区：[1]中南大学材料科学与工程学院 [2]中南大学有色金属材料科学与工程教育部重点实验室

出　　处：《特种铸造及有色合金》2017年第12期1283-1287,共5页Special Casting & Nonferrous Alloys

基　　金：广东省省级科技计划资助项目(2016B090931004)

摘　　要：采用Gleeble-3180热模拟试验机对均匀化退火态Al-5.87Zn-2.07Mg-2.28Cu合金在不同温度(350~450℃)和不同应变速率(0.01~10s^(-1))下进行热压缩试验。结果表明,在各真应变下合金的能量耗散因子均随温度的升高和应变速率的下降而增大;随着真应变增加,流变失稳区域扩大且合金适宜的热加工参数发生改变;随着变形温度的升高和应变速率的降低,合金的流变应力减小,且其主要软化机制由动态回复向动态再结晶转变;当变形温度达到420℃时,合金在各应变速率下均发生了动态再结晶。Hot compression tests of the homogenized Al-5.87 Zn-2.07 Mg-2.28 Cu alloy were performed on the Gleeble-3180 thermal simulation machine at the temperature range of 350450℃and the strain rate range of 0.0110 s-1.The results show that the power dissipation efficiency of the alloy is increased with increasing temperature and decreasing strain rate at each true strain.The flow instability region is enlarged and the optimum processing parameters of the alloy are changed with increasing strain.With increasing in deformation temperature and decreasing strain rate,the flow stress of the alloy is decreased,and the main softening mechanism is changed from dynamic recovery to dynamic recrystallization.When the temperature is 420 ℃,the dynamic recrystallization occurs at all strain rates.

关 键 词：AL-ZN-MG-CU合金 热变形 加工图 显微组织 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG249.2[金属学及工艺—金属材料]