ECAP对极冷超高强度7055铝合金组织和性能的影响  

Effect of ECAP on Microstructure and Properties of Extremely Cold Ultra High Strength 7055 Aluminum Alloy

作　　者：郭文静 GUO Wenjing(School of Metallurgy,Anhui University of Technology,Maanshan 243000,China)

机构地区：[1]安徽工业大学冶金学院,安徽马鞍山243000

出　　处：《热加工工艺》2024年第24期121-126,130,共7页Hot Working Technology

基　　金：国家自然科学基金青年科学基金项目(51805002)。

摘　　要：为了研究大塑性变形技术中的等通道转角挤压技术(ECAP)对极冷超高强度7055铝合金组织与性能的影响,对7055铝合金加热至480℃后进行ECAP热挤压试验,再采用OM、EBSD、TEM等技术手段对其组织特征和性能进行检测与分析。结果表明,7055铝合金的平均晶粒尺寸明显减少,大角度晶界所占比例有所降低,但仍大于等于66%,比例依然很高;且ECAP在基体中引入大量位错,促进了析出相的形核,增强了合金的析出强化效果;同时,合金的硬度也有一定的提升。采用ECAP工艺可对一定体积的材料施加较大的剪切变形而有效地细化晶粒,改善材料的微观组织,从而提高材料强度和韧性等综合力学性能。In order to study the effect of equal channel angular pressing(ECAP)on the microstructure and properties of ultra cold ultra high strength 7055 aluminum alloy,the aluminum alloy was heated to 480℃for ECAP hot extrusion test,and then its microstructure and properties were detected and analyzed by OM,EBSD,TEM and other technical means.The results show that the average grain size of 7055 aluminum alloy is significantly reduced,and the proportion of large angle grain boundary is reduced,but it is still higher than or equal to 66%,the proportion is still high.Moreover,a large number of dislocations are introduced into the matrix by ECAP,which promotes the nucleation of precipitates,enhances the precipitation strengthening effect of the alloy;at the same time,the hardness of the alloy also has a certain improvement.By applying large shear deformation to a certain volume of material,the ECAP process can effectively refine the grain size,improve the microstructure of the material,and improve the comprehensive mechanical properties of the material,such as strength and toughness.

关 键 词：等通道转角挤压技术(ECAP) 7055铝合金 微观组织 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]