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Indexed by:期刊论文

Date of Publication:2021-01-10

Journal:VIRTUAL AND PHYSICAL PROTOTYPING

Volume:15

Issue:4

Page Number:445-459

ISSN No.:1745-2759

Key Words:Laser-TIG hybrid additive manufacturing; heat treatment; high strength aluminum alloy; microstructure evolution; strengthening mechanism

Abstract:After solution + artificial aging treatment (T6 heat treatment) of 2219 aluminum alloy fabricated by laser-tungsten inert gas (TIG) hybrid method, more interestingly, we found that both the strength and elongation were improved. The strengthening mechanism has been analysed in details. Results showed that each layer was divided into the arc zone (AZ) and laser zone (LZ) before and after heat treatment. After T6 heat treatment, the columnar crystal grain morphologies remained the same as the as-deposited condition, while the microstructure presented a strong {001} texture along the building direction. Moreover, the high density of the needle-shaped theta '' phases were uniformly precipitated after artificial aging. Distinct grain morphology, increased the mass fraction of Cu in the Al matrix, and nano-precipitates in the AZ and LZ improved the tensile properties, which exhibited a yield strength of 242.1 +/- 19.6 MPa, an ultimate tensile strength of 407.1 +/- 31.1 MPa, respectively.
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