A novel bypass-gas metal arc directed energy deposition for in-situ synthesis Al-Cu-Li alloy: exploring the microstructure and mechanical properties evolution from as-deposited state to T6 state
Description
A novel bypass-gas metal arc directed energy deposition (bypass-GMA DED) was proposed to prepare high strength Al-Cu-Li-based components. An Al-5.51Cu-0.48Li alloy was successfully prepared, followed by subsequent T6 treatment. The microstructure evolution and improvement of mechanical properties after the T6 state were benchmarked against the as-deposited condition. The component fabricated by bypass-GMA DED has obvious periodic distribution characteristics, with a large number of fine equiaxed grains distributed near the interlayer fusion boundary and coarse columnar grains within the intralayer region. After heat treatment, the Al-5.51Cu-0.48Li alloy is mainly composed of four types of strengthening phases, θ’, θ”, δ’ and T1, which contrasts with the sole presence of θ phase in the deposited condition. These phases are conducive to the improvement of mechanical properties. The strength of the prepared alloy is higher than those additively manufactured Al-Cu-Li alloys, reaching values similar to those of conventional third generation Al-Cu-Li alloys.
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Institutions
- AVIC Beijing Aeronautical Manufacturing Technology Research Institute
- University of Electronic Science and Technology of China
- Hebei University of Science and Technology
- Universidade Nova de Lisboa
- Yanshan University