采用光纤激光焊接AZ91D镁合金,借助金相显微镜、X射线衍射仪、扫描电镜、透射电镜分别对焊接接头的微观组织结构、相组成、断口形貌进行分析.结果表明:光纤激光焊接AZ91D镁合金,能够得到无明显缺陷的焊接接头,焊缝组织为细小的柱状晶组织,接头热影响区小.焊缝组织由过饱和α-Mg固溶体和Al_2Mg相组成,焊缝金属冷却速度较快,没有β-Mg_(17)Al_(12)脆性相析出.α-Mg晶内和晶界上有少量Al_2Mg析出物,且存在大量位错线和位错胞.断口特征为韧脆混合断裂形式,有微小裂纹存在.
The microstructure, phase composition and fracture surface of joint of Mg alloy AZ91D by fiber laser welding were investigated by the metallographic microscope, XRD, SEM and TEM. The results show that sound welds without major defects can be produced, the microstructures of weld metal are significantly finer columnar crystals grain and no obvious heat effected zone is found. The microstructure of weld seam is composed of the oversaturated α-Mg solid solution and Al_2Mg phase. No brittle phase of β-Mg_(17)Al_(12) is precipitated due to rapid cooling speed. The second phase of Al_2Mg distributed inside the α-Mg grains and located at the grain boundaries. Lots of dislocation lines and dislocation cells exist in α-Mg grains. The fracture surface shows mixture fracture with small crack.
参考文献
| [1] | Robert E.[J].Light Metals Age,2001(06):54. |
| [2] | 冯吉才,王亚荣,张忠典.镁合金焊接技术的研究现状及应用[J].中国有色金属学报,2005(02):165-178. |
| [3] | Munitz A;Cotler C;Stern A et al.[J].Materials Science and Engineering,2001,A302:68. |
| [4] | Toshikatsu Asahing;Hiroshi Tokisuje;Kazuyoshi katoh .[J].Japanese Journal of Institute of Light Metals,1999,49(12):595. |
| [5] | Sun Z;Pan D;Wei J .[J].Science and Technology of Welding and Joining,2002,7(06):343. |
| [6] | Kuo T Y;Lin H C .[J].Materials Science and Engineering,2006,A416:281. |
| [7] | Munitz A;Cotler C .[J].Materials Science and Engineering,2001,A302:68. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%