On weldability of aerospace grade Al-Cu-Li alloy AA2065 by wire-feed laser metal deposition

Abstract

Al-Cu-Li alloys exhibit a superior strength to weight ratio, making the alloys attractive for applications within aviation and aerospace. However, their widespread application has been somewhat limited by the challenges associated with porosity and crack formation during welding. The purpose of this study was to evaluate the weldability of aerospace grade Al-Cu-Li alloy AA2065 by wire-based Laser Metal Deposition (LMD) by using a self-produced wire. The influence of selected process parameters on deposition geometry (width, height and deposition depth), porosity, microstructure and hardness were evaluated by producing single tracks on a base plate. Defect-free tracks with minimal porosity could be produced with a laser power of 2700 W, 800 μm spot size and 1 m/min scanning speed, providing an energy density of 5.4 J/mm2. Depending on the desired deposition rate, the wire-feed rate could be varied between 1 and 1.9 m/min. The microstructure of the deposited material consisted of columnar and globular equiaxed grains with a Cu-rich second phase network throughout the deposited material. The results presented in this study show the potential in utilizing wires produced of AA2065 for laser welding and potentially additive manufacturing by wire-based LMD, increasing the possible areas of application for such high-strength, low weight alloys.

Keywords

• Laser metal deposition
• Wire
• Al-Cu-Li alloys
• Aerospace
• Process parameters