riction surfacing (FS) is a solid state coating process based on the plastic deformation of a metallic consumable rod. As depicted in a rotating rod is pressed against the substrate under an applied axial load. Frictional heat generates a viscoplastic boundary layer at the rod tip. The pressure and temperature conditions lead to an inter diffusion process resulting in a metallic bond between the plasticized material and the substrate. Heat conduction into the substrate enables this layer to consolidate near the bonded interface, and as such, the viscoplastic shearing interface is formed between the rotating consumable rod and the deposited layer. With the on-going heat conduction, this viscoplastic shearing interface moves away from the substrate surface, increasing the thickness of the layer. By applying a travelling movement, the viscoplastic material is deposited onto the substrate surface in a continuous process. Note that FS…show more content… The authors presented relationships between the exposure time, the rod diameter and travel speed. In the FS of steels, the diameter determined the time period extension in which the coating material undergoes austenization before cooling.
FS process modeling does not allow geometric simplification by symmetry, because it deals with asymmetric material flow around the consumable rod.
The materials thermo-mechanical properties vary throughout the process, depending on temperature and strain rate. These properties are not accessible for most of the engineering materials.
During the deposition period the heat generated at the rubbing interface depends on an unknown varying friction coefficient.
The heat energy flowing into the clamping system, substrate material and backing plate is fundamental in order to predict the metallurgical final properties and joining mechanisms.