A review of friction stir processing in fabricating surface composites for process control and sensor data monitoring

Friction stir processing (FSP) is a solid-state deformation process that refines the surface microstructure. FSP is used to fabricate the surface composites and improve the mechanical properties, e.g., strength, hardness, ductility, wear, corrosion resistance, abrasion resistance, etc. Nowadays, FSP is a recommended method for preparing surface composite laminates made up of lightweight aluminium alloys, resulting in uniform distribution of the reinforcements into the matrix the refined microstructure at the surface up to a certain depth without affecting the bulk properties. In composites' fabrication by FSP, the refined microstructure is obtained at a temperature below the melting point. It eliminates the defects caused during other methods of fabrication that involve melting, solidification, etc., and enhanced mechanical properties evolve. This paper represents a review of the research work in FSP in the fabrication of hybrid layered composites in the context of sensor data monitoring and process control. In FSP, various sensors like- force, temperature, vibration, etc., are used to collect the data. The data is analyzed to monitor the machine condition, reduce the tool wear, improve surface microstructure, predict process anomalies, etc. This work in FSP is quite rare and has an excellent scope to be studied further.