Effect of artificial ageing temperature in t6-heat treatment on the mechanical properties of dissimilar metals weld between aa5083 and aa6063

Purpose: Aluminium AA5083 is commonly utilised in constructing ship hull shells, which are welded with aluminium AA6063 to act as stiffeners. However, the joints often suffer structural damage, such as longitudinal and transverse cracks in the dissimilar weld area, particularly in the Heat-Affected Zone (HAZ) of AA6063, which includes frames, brackets, and collars. To enhance the mechanical properties of AA6063, T6 heat treatment is commonly employed. The given study investigates the impact of temperature in artificial ageing during the T6 heat treatment on the microstructure and mechanical properties of the dissimilar materials welding between AA5083 and AA6063. Design/methodology/approach: The T6 heat treatment variations involve a solution treatment at 540°C for 6 hours, followed by quenching and artificial ageing at temperatures of 158°C, 200°C, and 230°C for 6 hours, followed by air cooling. The T6 heat treatment variations involve a solution treatment at 540°C for 6 hours, followed by quenching and artificial ageing at temperatures of 158°C, 200°C, and 230°C for 6 hours, followed by air. The weld joints were visually inspected and examined using radiography, then characterised by microstructure investigation and tensile and impact tests. Findings: The study's findings reveal that the T6 heat treatment significantly improves the mechanical properties of AA6063. However, the T6 heat treatment does not notably affect the mechanical properties of AA5083, the fusion line and the weld metal area. Among the artificial ageing temperature variations, the highest mechanical properties are achieved at 200°C, while the lowest mechanical properties are observed at 230°C. Research limitations/implications: Aluminium AA5083 is commonly utilised in constructing ship hull shells, which are welded with aluminium AA6063 to act as stiffeners. However, the joints often suffer structural damage, such as longitudinal and transverse cracks in the dissimilar weld area, particularly in the Heat-Affected Zone (HAZ) of AA6063, which includes frames, brackets, and collars. The paper focused on the influence of artificial ageing temperature in T6 heat treatment on the microstructure and mechanical properties of the dissimilar metals welding between AA5083 and AA6063. Oiginality/value: The optimum artifcial ag ing temperature in T6 heat treatment for th dissimilar metals welding between AA5083 and AA6063 was 200°C. Themethodcan be applied in ship tructur s wher AA5083 is typically utilised for constructing the hull shells, while AA6063 is employed as stiffeners.