GTAW Butt Welded 6061-T6 Aluminum: Post-process Heat Treatment Effect on Mechanical and Microstructural Features
Welding of aluminum remains an important area of research, driven by current challenges, such as the observed reduction in mechanical properties after the joining process, commonly referred to as softening. Particularly, there is limited information on the impact of heat treatments on the mechanical properties of joints in AA6061 alloy. This study addresses this gap by presenting mechanical properties of AA6061 joints under three distinct conditions: one in its welded state and two subjected to different subsequent heat treatments. Findings reveal that joining process parameters, defects, and applied heat treatment influence joint efficiency. Primarily, subsequent heat treatments substantially impact the microstructure and final mechanical properties of the weld. Solubilizing heat treatment effectively dissolves precipitates in the microstructure, while aging treatment successfully restores mechanical properties due to precipitation hardening. However, it is crucial to note that joint defects play a key role in determining final mechanical properties and crack location post-fracture. Additionally, the mechanical strength of the joint is studied in tensile tests at different temperatures, finding that this parameter reaches its maximum value at low temperatures and decreases with increasing temperature. In contrast, elongation is more significant at higher temperatures, but reduced at lower temperatures. This comprehensive analysis addresses the interaction between welding conditions, heat treatments, and microstructural changes, providing valuable information for improving the joining process and enhancing mechanical performance in AA6061-T6 aluminum joints.
Keywords: Aluminum alloys, Welding, Heat treatment, Mechanical properties, Microstructure.
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