摘要
211ZX铝合金是新一代Al-Cu-Mn系耐热高强韧铝合金,为进一步提升该材料的室温成形性、力学性能和工业应用价值,通过形变热处理工艺在该合金中构筑了由超细晶、纳米晶、位错网状结构和纳米析出相组成的复合结构,使纳米薄板材的拉伸强度和塑性同时得到提高。该工艺包括固溶处理、室温多道次累积轧制变形和后续低温时效。相较于传统T6态,复合纳米结构使合金的屈服强度提升了~213 MPa,与大变形制备的211ZX铝合金纳米薄板材相比,该复合纳米结构使合金的均匀延伸率提升了~5%。通过X射线衍射仪(XRD)、激光共聚焦显微镜(CLSM)和透射电子显微镜(TEM)等微观结构表征,结合强化机制的分析,研究发现细晶强化和析出强化对具备复合结构薄板材的材料屈服强度贡献最大。借助硬度、拉伸曲线、断口截面TEM分析、位错密度及纳米析出相的演变规律分析,可以明确位错回复和高密度的纳米析出相是提升211ZX铝合金板材塑性的主要因素。
With the increasing requirements for light weight metal materials,the application of 2-series Al-Cu alloys in industry was becoming more and more extensive.211ZX aluminum alloy was a new generation of Al-Cu series alloy in dependently developed by China.In order to expand the application of the material in industry,it was necessary to improve its room temperature formability and mechanical properties.The method to improve the formability and mechanical properties of the alloy at room temperature was thermomechanical treatment,which included solution treatment,multi-pass rolling deformation at room temperature and low temperature aging.Four equal sheets of 20 mm×30 mm×5 mm were cut from the original sample.The first sheet was aged at 160℃for 10 h(T6 treatment).The second sheet was subjected to two passes of rolling deformation with a true strain of 2.04 at room temperature.After ten passes of rolling deformation with true strain of 2.04,the third and fourth sheet were aged for 30 h at 100 and 160℃,respectively.The mechanical properties of the samples were tested by hardness and tensile tests.Through X-ray diffraction(XRD),confocallaser scanning microscopy(CLSM)and transmission electron microscopy(TEM)microstructure characterization,the micro morphology and precipitation of the alloy in different states were observed respectively.Through the analysis of the microstructure and mechanical properties,the following conclusions could be drawn:(1)After the solution treated sample was deformed by two passes with a true strain of 2.04,the surface had obvious macroscopic appearance.Cracks and rolling defects,while the surface integrity of the sample after ten passes of rolling deformation was better without obvious defects.(2)In the sheet after ten-pass rolling deformation,the grains on transverse direction-normal direction(TD-ND)surface were elongated into a layered structure,and S-shaped shear bands could be observed on rolling direction-normal direction(RD-ND)surface.(3)The hardness of the rolled sheet reached its
作者
刘青青
胡德玲
杨明
李波
黄朝文
Liu Qingqing;Hu Deling;Yang Ming;Li Bo;Huang Chaowen(College of Materials and Metallurgy,Guizhou University,Guiyang 550025,China;High Performance Metal Structure Material and Manufacture Technology National Local Joint Engineering Laboratory,Guiyang 550025,China;Guizhou Electric Power Research Institute,Guiyang 550025,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2023年第7期959-966,共8页
Chinese Journal of Rare Metals
基金
贵州大学大学生创新创业训练计划项目(贵大(国)创字2019(003))
贵州省自然科学基金重点项目(ZK[2021]重点054)
贵州大学引进人才项目(贵大人基合字[2017]02)资助
关键词
211ZX铝合金
超细晶
纳米析出
力学性能
211ZX aluminum alloy
ultrafine grain
nano-precipitation
mechanical properties
