Influence of machine parameters on material flow behavior during channeling in modified friction stir channeling

Material flows during friction stir processes are very complex and not fully understood. Although the most literature reviews are presenting for material flow path, but Modified Friction Stir Channeling (MFSC) is a novel process based on Friction Stir Processing (FSP), which is being utilized to produce internal channel in Monolithic plates. A new flow pattern, in this study, is proposed to investigate material flow path and channel formation mechanism. The validity of this model is demonstrated by observing the cross-section and created keyhole using stop-action technique. The main difference between Friction Stir Channeling (FSC) and MFSC is the tilt angle. The effect of tilt angle and process parameters such as rotational speed and traverse speed on material flow path is studied. The results indicate that the tilt angle is an effective factor on forging of material behind of pin in the Advancing Side (AS) and also in the upper portion of channel roof imperfections. The rotational speed is an effective parameter on extruded material around the tool pin body and the extracted material in front of tool pin, because of the changing in the slip-stick condition and generated heat by tool. Traverse speed was an effective parameter on forging action of material and to keep material nearby tool pin in the behind of pin.