• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报

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冷喷铝涂层对2024铝合金搅拌摩擦焊接头力学性能的影响

张志函1, 2,  蒋若蓉1, 2,  李文亚1, 2   

  1. 1. 西北工业大学材料学院  西安  710072;
    2. 西北工业大学凝固技术国家重点实验室  西安  710072
  • 收稿日期:2015-05-06 修回日期:2015-08-17 出版日期:2015-11-15 发布日期:2015-11-15
  • 通讯作者: 李文亚,男,1976年出生,博士,教授,博士研究生导师,材料学院副院长。主要研究方向为摩擦焊与冷喷涂。 E-mail:liwy@nwpu.edu.cn
  • 作者简介:作者简介:张志函,男,1985年出生,博士研究生。主要研究方向为搅拌摩擦焊。 E-mail:hanhizi@163.com
  • 基金资助:
    凝固技术国家重点实验室自主课题(108-QP-2014)、北京科技大学新金属材料国家重点实验室开放课题(2013-ZD07)和中央高校基本科研业务费专项资金(3102014JC02010404)资助项目

Influence of Cold Sprayed Aluminum Coating on the Mechanical Properties of Friction Stir Welded 2024 Aluminum Alloy Joints

ZHANG Zhihan1, 2,  JIANG Ruorong1, 2,  LI Wenya1, 2   

  1. 1. School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072;
    2. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072
  • Received:2015-05-06 Revised:2015-08-17 Online:2015-11-15 Published:2015-11-15

摘要: 冷喷涂层为搅拌摩擦焊(Friction stir welding, FSW)接头提供了良好的防腐效果,但冷喷涂层对FSW接头力学性能的影响尚不明确。基于此,本研究通过拉伸和疲劳试验研究冷喷涂层对2024-T3铝合金接头力学性能的影响,并采用透射电子显微镜(Transmission electron microscope, TEM)与差示扫描量热法(Differential scanning calorimetry, DSC)表征冷喷涂前后接头显微组织的变化。试验结果表明,在2024-T3铝合金FSW接头上制备冷喷涂层后,接头的力学性能得到了一定改善,其抗拉强度从393.3 MPa提高到420.0 MPa,伸长率从4.3%增加到6.9%。当疲劳循环次数为1×107时,喷涂后的FSW接头在50%存活率下的疲劳强度比焊态高29.1%,在95%存活率下的比焊态高30.9%。TEM和DSC结果表明,喷涂后焊核区S相的数量、Cu与Mg原子偏聚区体积分数明显增多,这可能是接头力学性能提升的内在原因。

关键词: 搅拌摩擦焊, 冷喷涂, 力学性能, 铝合金

Abstract: Cold sprayed aluminum coatings enhanced obviously the corrosion resistance of friction stir welding(FSW) joints, but the influence of cold sprayed Al coatings on the mechanical properties of FSW joints is still unclear. The effect of cold sprayed Al coatings on the mechanical properties of FSW joints is investigated by tensile tests and fatigue tests. Microstructure change of FSW joints before and after cold spraying is also examined by transmission electron microscope(TEM) and differential scanning calorimetry(DSC). Results show that the mechanical properties of the FSW AA2024-T3 joints are improved after cold spraying. Tensile strength and elongation of coated specimen increase by about 27 MPa and 60.5%, respectively, compared to those of 393.3 MPa and 4.3% of as-welded specimen. When the fatigue life is 1×107 cycles, the fatigue strength corresponding to a 50% survival probability of coated specimens is 29.1% higher than that of the as-welded specimen, and the fatigue strength corresponding to a 95% survival probability of coated specimens is 30.9% higher than that of the as-welded specimens. After cold spraying, the volume fractions of S phase and Guinier-Preston-Bagaryatskii(GBP) zone in nugget zone increases, which is possibly a main reason for the improvement of the mechanical properties.

Key words: aluminum alloy, cold spraying, friction stir welding, mechanical properties