Mechanical performance and microstructural characterisation of titanium alloy-alloy composites built by wire-arc additive manufacture

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

卷:765

Article

Davis, A. E.¹  Breheny, C., I¹  Fellowes, J.²  Nwankpa, U.³  Martina, F.³  Ding, J.³  Machry, T.⁴  Prangnell, P. B.¹ 

[1] Univ Manchester, Sch Mat, Manchester M13 9PL, Lancs, England

[2] Univ Manchester, Sch Earth & Environm Sci, Manchester M13 9PL, Lancs, England

[3] Cranfield Univ, Welding Engn & Laser Proc Ctr, Cranfield MK43 0PL, Beds, England

[4] Satair, Airbus Operat, Airbus SAS, D-22335 Hamburg, Germany

关键词: Titanium alloys;    Additive manufacturing;    Characterization;    Grains and interfaces;    Mechanical properties;    Fracture behaviour;   

DOI  :  10.1016/j.msea.2019.138289

来源: Elsevier

【 摘 要 】

A first stage study has been performed to investigate the potential for exploiting high deposition rate WAAM to print dual-alloy microstructures. Samples were built using alternating feed wires of commercially-pure Ti and Ti-6Al-4V. A high level of dilution occurred during deposition accompanied by effective liquid-phase mixing, producing a regular distribution of solidified melt tracks of approximate bimodal composition each less extreme than that of their respective constituent feed wires. The yield strength of the dual alloy composite material was approximately midway between that of the two alloys from which it was produced and exhibited a double inflection yield behaviour. Overall, because of the relatively coarse length scale there was not a significant property advantage in tensile loading above that of a chemically homogenous material, thus the main advantage of printing alternate alloys at this length scale is likely to reside more with increasing crack path tortuosity during fracture or fatigue loading. Importantly, the deposited material was found to have a refined beta-grain structure suggesting that the composition gradients introduced by dual-alloy printing can disrupt the epitaxial columnar growth normally seen in WAAM deposits.

【 授权许可】

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