ZM5镁合金薄壁铸件光纤激光补焊工艺与组织性能研究

发布时间：2018-03-18 16:47

本文选题：激光技术　切入点：ZM镁合金　出处：《中国激光》2015年02期 　论文类型：期刊论文

【摘要】：采用光纤激光对ZM5镁合金薄壁铸件进行补焊研究,以焊道稀释率和表面交角进行工艺评价,通过扫描电子显微镜(SEM)和X射线衍射(XRD)表征了样品的显微组织、相组成,并作了拉伸试验分析。结果表明,补焊焊缝稀释率和焊道表面交角成线性相关变化,补焊层由细小的等轴树枝晶组成,平均晶粒直径为15~20μm,约为ZM5母材的1/4;补焊层基体组织为α-Mg相,晶界析出Mg-Al共晶相,其中β-Mg17Al12以连续网状或不规则的点状析出;补焊层抗拉强度和延伸率优于母材,补焊层拉伸断口为准解理断裂,断口有少量韧窝,而经均匀化热处理的母材断口为脆性断裂的解理断口。组织表征和性能试验表明,光纤激光可实现ZM5镁合金铸件的缺陷补焊,且在工艺上具有很好的适应性。
[Abstract]:The fiber laser welding of ZM5 magnesium alloy castings, process evaluation to weld dilution rate and surface angle, by scanning electron microscopy (SEM) and X ray diffraction (XRD) characterization of the microstructure and phase composition of samples, and the tensile test analysis. The results show that the welding seam dilution rate and a linear bead surface angle changes, welding layer is composed of equiaxed dendrite, the average grain diameter of 15~20 m, about ZM5 of base metal 1/4; welding layer matrix structure for a -Mg phase, grain boundary precipitation of Mg-Al eutectic phase, the beta -Mg17Al12 to point precipitation of continuous net or not rule; fill the tensile strength of the welded layer and the elongation is higher than that of base metal, weld layer tensile fracture to quasi cleavage fracture, the fracture has a small dimple, base metal fracture and after uniform heat treatment for brittle fracture of cleavage fracture. Show tissue characterization and performance test, optical fiber The laser can be used to repair the defects of ZM5 magnesium alloy castings and have good adaptability in the process.

【作者单位】：上海交通大学上海市激光制造与材料改性重点实验室;
【分类号】：TG456.7

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