Al-Zn-Mg-Cu新型高强铝合金热变形组织演变机理和规律  

Microstructure mechanisms and evolution during hot deformation of a new Al-Zn-Mg-Cu high strength aluminum alloy

作　　者：张坤[1] 李惠曲[1] 陈慧琴[2] 白林振[2] 

机构地区：[1]中航工业北京航空材料研究院,北京100095 [2]太原科技大学,山西太原030024

出　　处：《轻合金加工技术》2010年第10期55-58,共4页Light Alloy Fabrication Technology

基　　金：国家重点基础研究973项目资助(2005CB623705)

摘　　要：采用Gleeble-1500D热力模拟试验机进行了新型Al-Zn-Mg-Cu高强铝合金的热压缩试验,变形温度为420℃-350℃,应变速率为0.01 s-1-1 s-1,变形程度为20%-80%。分析了热变形参数（变形温度、应变速率和变形程度）对组织演变机理和规律的影响。结果表明,温度和变形程度显著影响该合金组织演变机理和规律。在试验温度范围内,压缩变形程度达到60%时,原始铸态组织完全转变为均匀的锻态组织。高温有利于该合金动态再结晶过程的发生,应变适中时,组织以不连续动态再结晶产生新晶粒,再结晶分数较少;应变很大时,组织发生几何动态再结晶,再结晶分数较高。低温时,锻态变形组织基本为加工硬化或动态回复组织。Hot compression tests of a new Al-Zn-Mg-Cu high strength alloy were carried out by Gleeble-1500D thermal-mechanical simulator at temperatures of 420-350℃,strain rates of 0.01 s-1-1 s-1 and reductions of 20%-80%.Influence of hot deformation parameters（temperature,strain rate and reduction） on microstructure evolution and mechanisms was analyzed.The results indicate that temperature and reduction level have remarkable effects on microstructure evolution and mechanisms during the alloy hot deformation.At the range of test temperatures,initial cast-structures became into homogenous forged structures when the reduction reach to 60%.Higher temperature promotes dynamic recrystallization of the alloy.Recrystallized new grains were developed by discontinuous dynamic recrystallization at moderate deformation strain,and recrystallized fraction was lower;Geometric dynamic recrystallization at large strains took place,and recrystallized fraction was higher.The forged deformation structures are basically work hardening or dynamic recovery structure when temperature was lower.

关 键 词：Al-Zn-Mg-Cu高强铝合金 热压缩变形 微观组织 

分 类 号：TG146.21[一般工业技术—材料科学与工程]