Microstructure and mechanical properties of a TiB 2-modified Al-Cu alloy processed by laser powder-bed fusion

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:799

Article

Mair, P.¹  Kaserer, L.¹  Braun, J.¹  Weinberger, N.²  Letofsky-Papst, I.^3,4  Leichtfried, G.¹ 

[1] Univ Innsbruck, Fac Engn Sci, Dept Mechatron, Mat Sci, Tech Str 13, A-6020 Innsbruck, Austria

[2] Univ Innsbruck, Fac Engn Sci, Dept Struct Engn & Mat Sci, Mat Technol, Tech Str 13, A-6020 Innsbruck, Austria

[3] Graz Univ Technol, NAWI Graz, Inst Electron Microscopy & Nanoanal, Steyrergasse 17, A-8010 Graz, Austria

[4] Graz Univ Technol, NAWI Graz, Ctr Electron Microscopy, Steyrergasse 17, A-8010 Graz, Austria

关键词: Laser powder-bed fusion;    High-strength aluminum alloys;    TiB2;    Additive manufacturing;    Selective laser melting;   

DOI  :  10.1016/j.msea.2020.140209

来源: Elsevier

【 摘 要 】

In this work, crack-free samples with a relative density of 99.5 +/- 0.1% were produced from a gas-atomized Al-Cu-Ag-Mg-Ti-TiB2 powder via laser powder-bed fusion. The homogeneous equiaxed microstructure without preferred grain orientation shows the alpha-Al grains' mean size to be 0.64 mu m +/- 0.26 mu m TiB2 particles with sizes of several tens of nm up to 1.5 mu m were observed in the as-built component. Small TiB2 particles of up to approx. 200 nm are located within the alpha-Al grains, which show a semi-coherent interface to the alpha-Al phase. Larger TiB2 particles of up to 1.5 mu m accumulate in the liquid between the growing alpha-Al grains during solidification and inhibit grain growth. Al2Cu phase is precipitated at the alpha-Al grain boundaries. Coarse Al2Cu precipitates, which are slightly enriched with silver and magnesium, are also observed within the grains preferentially precipitated on small pores and TiB2 particles. The novel fine-grained microstructure results in the as-built state in a tensile strength of 401 +/- 2 MPa and total elongation at fracture of 17.7 +/- 0.8%.

【 授权许可】

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