| 引用本文: | 马杰,刘芳,王佳媛,符彩涛.退火对ECAP纯铝组织结构、力学及腐蚀性能的影响[J].材料科学与工艺,2019,27(5):91-96.DOI:10.11951/j.issn.1005-0299.20180120. |
| MA Jie,LIU Fang,WANG Jiayuan,FU Caitao.Effect of annealing process on microstructure, mechanical and corrosion properties of ECAP pure aluminum[J].Materials Science and Technology,2019,27(5):91-96.DOI:10.11951/j.issn.1005-0299.20180120. |
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| 摘要: |
| 为研究高温后超细晶纯铝的力学性能和耐腐蚀性能变化，本文在室温下对99.6%的纯铝(CP-Al)进行等通道转角挤压(ECAP)后，获得超细晶纯铝.在8道次、Bc挤压路径，不同退火温度下，通过X射线衍射、扫描电子显微镜、单向拉伸与硬度测试及电化学测试分析，对其力学性能、组织结构、耐腐蚀性进行了研究.实验结果表明，随着退火温度的升高，8道次ECAP纯铝的强度和硬度降低，塑性逐渐提高；其在未退火及150、250、350 ℃退火后的硬度和抗拉强度分别为99.4HV，279.6 MPa、94HV，276.2 MPa、80HV，220.6 MPa、47HV，209.5 MPa；延伸率分别为4.89%、5.68%、9.81%、12.10%；晶粒尺寸由612 nm增加到1 314 nm，晶面取向发生变化.在质量分数为3.5% NaCl溶液中，对8道次ECAP纯铝在不同退火温度下分别进行了极化曲线和电化学阻抗谱(EIS)测试，并观察了显微结构图，结果表明，ECAP 8道次挤压后，随着退火温度的增加纯铝的腐蚀电流密度由未退火时的5.756 μA/cm2略减少到150 ℃的5.732 μA/cm2，而后增加到300 ℃的6.846 μA/cm2，腐蚀形貌发生改变.退火温度为150 ℃时，纯铝表现出更好的耐腐蚀性能，这是由于退火温度增加会减少材料缺陷，但晶粒增大对耐腐蚀性的抑制高于材料微观结构改善对耐腐蚀性的促进. |
| 关键词: 等通道转角挤压 退火温度 力学性能 微观组织 耐腐蚀性 |
| DOI：10.11951/j.issn.1005-0299.20180120 |
| 分类号:TG379; TG146.2+ |
| 文献标识码:A |
| 基金项目: |
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| Effect of annealing process on microstructure, mechanical and corrosion properties of ECAP pure aluminum |
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MA Jie,LIU Fang,WANG Jiayuan,FU Caitao
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(School of Materials of Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China)
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| Abstract: |
| At present, little research has been done on the mechanical properties and corrosion resistance of ultrafine-crystalline pure aluminum after high-temperature treatment. In this paper, 99.6% pure aluminum (CP-Al) was subjected to Equal Channel Angular Pressing (ECAP) at room temperature to obtain ultrafine crystalline pure aluminum. X-ray diffraction, scanning electron microscopy, uniaxial tensile and hardness testing, and electrochemical test analysis were carried out on 8 passes, Bc extrusion path, and at different annealing temperatures. The mechanical properties, microstructure, and corrosion resistance were investigated. The experimental results show that with the increase of annealing temperature, the strength and hardness decreased, and the plasticity increased gradually. The hardness and tensile strength of 8 times of ECAP pure aluminum in unannealed and at 150, 250 and 350 ℃ were 99.4HV, 279.6 MPa, 94HV, 276.2 MPa, 80HV, 220.6 MPa, and 47HV, 209.5 MPa, respectively; elongations were 4.89%, 5.68%, 9.81%, and 12.10%, respectively; grain size increased from 612 nm to 1 314 nm, and the crystal plane orientation changed. In NaCl solution with mass fraction of 3.5%, 8 times of ECAP pure aluminum was tested by the polarization curve and electrochemical impedance spectroscopy (EIS), and its microstructure was observed. The results show that after ECAP 8 passes, with increasing annealing temperature the corrosion, current density was slightly reduced from 5.756 μA/cm2 at the time of non-annealing to 5.732 μA/cm2 at 150 ℃, and then increased to 6.846 μA/cm2 at 300 ℃, and the corrosion morphology changed. Pure aluminum with an annealing temperature of 150 ℃ exhibited better corrosion resistance. This is because the increase of annealing temperature reduced the material defects, but the inhibition of corrosion resistance by the increase of grain was higher than that by the improvement of microstructure. |
| Key words: equal channel angular pressing (ECAP) annealing temperature mechanical properties microstructure corrosion resistance properties |
