固溶处理对7B04-O铝合金搅拌摩擦焊接接头微观组织与力学性能的影响

发布时间：2018-10-13 15:48

【摘要】：对航空用3 mm厚的带有包铝层的7B04-O铝合金板材进行搅拌摩擦焊接(Friction stir welding,FSW),研究固溶处理对搅拌摩擦焊接接头的微观组织和力学性能的影响。结果表明,当转速为800 r/min、焊接速度为200 mm/min、焊接工具轴肩直径为12 mm时,可得到表面美观、致密无缺陷的搅拌摩擦焊接接头。焊核区发生动态再结晶,形成细小的等轴晶。经固溶处理后,焊核的上部及底部晶粒都发生了异常长大,而中部区域晶粒仍然为细小的等轴晶组织。焊态接头的拉伸试样断裂在母材位置,抗拉强度达到199 MPa,与退火态母材抗拉强度相当,断后伸长率达到12%。在新淬火状态下,接头的抗拉强度为310 MPa,为相同热处理母材的91.4%,断后伸长率为11.2%,试样断裂在焊核区,呈不完全的韧性断裂。
[Abstract]:The effect of solution treatment on the microstructure and mechanical properties of 7B04-O aluminum alloy plate with 3 mm thick aluminum coating was studied by friction stir welding (Friction stir welding,FSW). The results show that when the rotating speed is 800 r / min and the welding speed is 200 mm/min, the shaft shoulder diameter of the welding tool is 12 mm, a compact friction stir welded joint with beautiful surface and no defect can be obtained. Dynamic recrystallization occurs in the nugget zone, forming fine equiaxed crystals. After solution treatment, the upper and bottom grains of the nugget grow abnormally, while the grains in the central region are still fine equiaxed structure. The tensile strength of the welded joint is about the same as that of the annealed parent metal, and the tensile strength of the welded joint is equal to that of the annealed parent metal, and the tensile strength of the welded joint is at the base metal position, and the elongation of the welded joint is 12%. Under the new quenching condition, the tensile strength of the joint is 310 MPa, which is 91.4 of the same heat treated base metal, and the elongation after breaking is 11.2. The specimen is broken in the nugget zone, showing incomplete ductile fracture.
【作者单位】：中航工业沈阳飞机工业(集团)有限公司;沈阳航空航天大学材料科学与工程学院;中国科学院金属研究所沈阳材料科学国家(联合)实验室;
【基金】：国家自然科学基金资助项目(51331008)
【分类号】：TG441.7;TG407

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