采用超声冲击工艺对母材为2A12铝合金焊接接头进行了焊后处理.利用扫描电镜、X射线衍射分析了超声冲击处理前后焊缝表面层的微观组织结构特征.结果表明,超声冲击处理可以在焊缝表面形成约为300μm的致密塑性变形层,晶粒明显细化.对X射线衍射峰的观察分析表明,处理后焊缝表层材料衍射峰明显宽化,这是超声冲击处理使焊缝表层材料粒子细化和晶格结构的微观应变引起的.利用谢乐方程和威尔逊公式对超声冲击处理后焊缝表层的晶粒度和微观应变进行了定量分析,结果表明,处理层的晶粒平均尺度为123nm,平均微观应变为0.134%.最后,对晶粒细化的机理进行了分析.
2A12 aluminum alloy welded joint was strengthened by Ultrasonic Impact Treatment (UIT). The microstructure characterization of the welded bead surface layer with and without UIT was studied by SEM observation and X-Ray Diffraction (XRD) analysis. Results show that the metallurgical structure of the near surface material of the weld zone was densified due to ultrasonic impact treatment. The depth of plastic deformation extended up to about 300μm from the surface. The grain refinement behavior was obvious. XRD analysis show that the diffraction peaks after UIT was broadened significantly, which was related to grain refinement and lattice distortions. Quantitative estimation of the grain size and of the lattice distortions after UIT was evaluated by Scherrer equation and Williamson formula based on the peak broadening. Results show that the average grain size after UIT is about 123nm and the average micro-strain value is about 0.134%. At last, the mechanisms of grain refinement were discussed.
参考文献
| [1] | 周万盛;姚君山.铝及铝合金的焊接[M].北京:机械工业出版社,2006 |
| [2] | 范成磊,方洪渊,田应涛,黎明.随焊冲击碾压对LY12CZ铝合金接头组织和性能的影响[J].材料工程,2004(10):24-28. |
| [3] | 徐滨士;朱绍华.表面工程的理论与技术[M].北京:国防工业出版社,1999 |
| [4] | 张文博,徐开国,张汝春.焊接接头疲劳强度的研究及其技术工艺的改进[J].煤矿机械,2005(03):70-73. |
| [5] | 王炳英,霍立兴,王东坡,张玉凤.等离子喷涂法改善焊接结构的疲劳性能[J].焊接学报,2006(12):97-100. |
| [6] | Mordyuk BN;Prokopenko GI .Ultrasonic impact peening for the surface properties' management[J].Journal of Sound and Vibration,2007(3/5):855-866. |
| [7] | AN X;RODOPOULOS C A;STATNIKOV E S et al.A study of the surface nano-crystallization induced by the esonix ultrasonic impact treatment on the near-surface of 2024-T351 aluminum alloy[J].Journal of Materials Engineering and Performance,2006,15(03):355-364. |
| [8] | Suh CM;Song GH;Suh MS;Pyoun YS .Fatigue and mechanical characteristics of nano-structured tool steel by ultrasonic cold forging technology[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2007(1/2):101-106. |
| [9] | Sougata Roy;John W. Fisher;Ben T. Yen .Fatigue resistance of welded details enhanced by ultrasonic impact treatment (UIT)[J].International Journal of Fatigue,2003(9/11):1239-1247. |
| [10] | 王东坡,霍立兴,张玉凤,陈俊梅,刘允辉.超声冲击法改善LF21铝合金焊接接头的疲劳性能[J].中国有色金属学报,2001(05):754-759. |
| [11] | Atef Korchef;Yannick Champion;Nabil Njah .X-ray diffraction analysis of aluminium containing Al_8Fe_2Si processed by equal channel angular pressing[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,2007(1/2):176-182. |
| [12] | 丛秋滋.多晶二维X射线衍射[M].北京:科学出版社,1997 |
| [13] | 刘存业;刘荣泰;邓昭镜 等.γ-三氧化二铁磁性超微粉粒径分析[J].西南师范大学学报(自然科学版),1990,15(01):57-60. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%