Friction plug repair welding technology has been demonstrated to be effective to repair the glass fiber-reinforced polyamide 6 sheets in the present paper. Influences of repair hole geometries and parameters on joint morphology and mechanical performance were investigated. Results showed that defect-free repaired joints were produced with the utilization of tapered holes rather than cylindrical holes. Process parameters exerted significant influences on the cross-sectional profile and morphology of the joints. Defect-free repaired welds with larger stir zone thicknesses were produced with the proper increase of rotational speeds, but excessive rotational speeds caused the formation of cavities along the plug boundary and the reduction of stir zone thicknesses. The fluctuation of the wavy bottom interface increased under larger plunge rates and incomplete connections between stir zone and base material were observed under plunge rate of 25 mm/min. Extended dwell time led to larger stir zone thickness and improved joint morphology. Tensile tests showed that the strength of the repaired joints increased and then decreased with the enlargement of rotational speeds. Decreased plunge rate and extended dwell time led to promoted joint mechanical performance. Three failure modes were observed, which corresponded to low, middle, and high repaired weld strengths.

中文翻译：

---

玻璃纤维增​​强聚酰胺 6 的摩擦塞补焊：形态、微观结构和机械性能的研究

摩擦塞补焊技术已被证明可有效修复本文中的玻璃纤维增​​强聚酰胺6片材。研究了修复孔几何形状和参数对接头形态和机械性能的影响。结果表明，使用锥形孔而不是圆柱孔可以产生无缺陷的修复接头。工艺参数对接头的横截面轮廓和形态产生重大影响。适当提高转速可得到搅拌区厚度较大的无缺陷修补焊缝，但转速过高会导致沿塞边界形成空腔，搅拌区厚度减小。在较大的插入速率下波状底部界面的波动增加，在 25 毫米/分钟的插入速率下观察到搅拌区和基材之间的连接不完整。延长停留时间导致更大的搅拌区厚度和改善的接头形态。拉伸试验表明，修复后的接头强度随着转速的增大而先增大后减小。降低的切入率和延长的停留时间导致关节机械性能的提高。观察到三种失效模式，对应于低、中和高修复焊缝强度。拉伸试验表明，修复后的接头强度随着转速的增大而先增大后减小。降低的切入率和延长的停留时间导致关节机械性能的提高。观察到三种失效模式，对应于低、中和高修复焊缝强度。拉伸试验表明，修复后的接头强度随着转速的增大而先增大后减小。降低的切入率和延长的停留时间导致关节机械性能的提高。观察到三种失效模式，对应于低、中和高修复焊缝强度。