Understanding the material flow in friction stir welding (FSW) is one of the challenging aspects for producing defect free and quality welds. The material flow is majorly governed by the tool shoulder/pin geometries and process conditions. In the present study, concentric circles shoulder shape with various polygonal pin designs are selected, and their influence on material flow and mechanical properties in Al 6082 friction stir welds is addressed. Material flow is studied by inserting the markers before welding and subsequent analysis of deformed marker material by radiography and macrostructure after welding. The outcome shows the welds with square pin design facilitated a constant stable force, and hexagonal pin design facilitated a decreasing behavior of force with reference to welding length/time. The heat input is increasing from triangular pin to hexagonal pin and is maximum for welds with hexagonal pins (973 kJ/mm). Further, welds with hexagonal pins (T_CC)_HEX tool facilitated higher mechanical properties of strength (187 MPa) and average hardness (79 HV) at the stir zone.

理解搅拌摩擦焊（FSW）中的材料流动是生产无缺陷和高质量焊缝的挑战之一。物料流主要由刀肩/销的几何形状和工艺条件决定。在本研究中，选择了具有各种多边形销设计的同心圆肩形状，并研究了它们对Al 6082搅拌摩擦焊缝中材料流动和机械性能的影响。通过在焊接之前插入标记并随后通过射线照相和焊接后的宏观结构对变形的标记材料进行分析，来研究材料流动。结果表明，相对于焊接长度/时间，采用方形销钉设计的焊缝促进了恒定的稳定力，而六角销钉设计则有利于减小力的行为。从三角形销到六角销的热量输入正在增加，对于带有六角销的焊缝，热量输入最大（973 kJ / mm）。此外，用六角销钉焊接（T_CC）_HEX工具有助于在搅拌区获得更高的强度（187 MPa）和平均硬度（79 HV）的机械性能。