Effects of Multi-Pass Friction Stir Processing on Microstructures and Mechanical Properties of the 1060Al/Q235 Composite Plate

Abstract

Steel cuttings, holes and cracks always exist at the interfaces in the composite plate. Multi-pass friction stir processing (M-FSP) is proposed in this research to optimize the interface microstructure and the interface connection for the 1060Al/Q235 composite plate. Results show that the microstructures of 1060Al after M-FSP are fine and uniform owing to the strong stirring effect and recrystallization. Micro-defects formed by the welding can be repaired by the M-FSP. However, tunnel defects can also be formed in the matrix of aluminum by M-FSP, especially when the passes are one and two. The melting block and the melting lump in the composite plates are easy to become the source of crack. The shear strengths and the bending properties for the 1060Al/Q235 composite plate after M-FSP are the best when the passes are three, with the tool rotation speed of 1200 rpm and the forward speed of 60 mm/min. The optimized interfaces for the composite plate after M-FSP are mainly by the metallurgical bondings, with a certain thickness and discontinuous mechanical connections. Therefore, the crack extension stress is the largest and the mechanical properties are the best.

Energy-efficient method for developing in-situ Al-Cu metal matrix composites using microwave sintering and friction stir processing

“…Fine and ultra-fine grains bear the maximum tensile load before fracture. A better interfacial bonding assists in the transfer of load to intermetallic particles [48][49][50]. A previous study reported that increased Cu content enhanced the UTS from 192 MPa (0wt%Cu) to 280 MPa (15wt%Cu) at the stirred zone.…”

Investigation of Mechanical and Microstructural Properties of Welded Specimens of AA6061-T6 Alloy with Friction Stir Welding and Parallel-Friction Stir Welding Methods

“…If the asymmetry in the temperature distribution and material flow in the FSW process can be eliminated and the process turns into a relatively symmetrical process, the mechanical quality of the joint can be improved [29][30][31]. Different solutions have been suggested to eliminate this disadvantage, which includes the use of Reverse Dual-Rotation Friction Stir Welding (RDR-FSW) [32,33], implementation of the FSW process using tandem tools, using Multi-Pass Friction Welding (MP-FSW) [34][35][36] with reverse rotation of the tool and the use of Parallel-Friction Stir Welding (P-FSW) [37].…”