The effects of post-processing on the local fracture toughness properties of electron beam powder bed fusion Ti-6Al-4V alloy

• Published in: Engineering fracture mechanics 2022-10, Vol.273, p.108697, Article 108697
• Main Authors: Dzugan, J., Seifi, M., Rzepa, S., Rund, M., Koukolikova, M., Viehrig, H.-W., Liu, Z.H., Lewandowski, J.J.
• Format: Article
• Language: English
• Subjects: Additive manufacturing; Fracture toughness; Local properties; Miniature tension and fracture toughness specimens
• ISSN: 0013-7944; 1873-7315
• DOI: 10.1016/j.engfracmech.2022.108697

•Small-sized specimen techniques were developed and applied to determine fracture critical properties representative for actual products produced by Electron Beam Melting.•Three material conditions were prepared, characterized microstructurally and evaluated mechanically: as-deposited, stress relieved, and HIP-ed.•Local mechanical properties are assessed with the use of miniaturized compact tension (MCT) fracture toughness specimens and miniaturized tensile tests (MTT)•The results are complemented by microstructural and fractographic analyses and are discussed in the light of literature values. Rapidly developing additive technologies for metallic parts production have led to the development of a wide range of methods supporting this field, including mechanical properties characterization. Components produced by AM processes are built spot to spot and layer by layer and that leads to varying local heat absorption and distribution, resulting in varying local properties depending on the shape complexity and build parameters. Different properties in different directions and at various component locations can be expected. Since AM parts are often sub-scale and/or with topological complexity, mechanical characterization with the use of standard specimens is not typically possible and small-sized specimen techniques have to be developed and applied. In the current paper, three AM produced parts made of Ti-6Al-4V by Electron Beam Powder Bed Fusion (EB-PBF) technology have been investigated. Three material conditions are reported here: as-deposited, stress relieved and HIP-ed. Local mechanical properties are assessed with the use of miniaturized compact tension (MCT) fracture toughness specimens and miniaturized tensile tests (MTT). The results are complemented by microstructural and fractographic analysis and are discussed in the light of literature values.