Additive manufacturing of Ti-6Al-4V lattice structures with high structural integrity under large compressive deformation. Issue 2 (February 2019)

• Record Type: Journal Article
• Authors: Yang, Kun; Wang, Jian; Jia, Liang; Yang, Guangyu; Tang, Huiping; Li, Yuanyuan
• Is Part Of: Journal of materials science & technology. Volume 35:Issue 2(2019)
• Page Start: 303
• Page End: 308
• Publication Date: 2019-02
• Subjects: Selective electron beam melting -- Ti-6Al-4V -- Lattice structures -- Ductility -- Annealing -- Beta annealing; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2018.10.029
• Languages: English
• ISSNs: 1005-0302

Abstract

Abstract: Additively manufactured Ti-6Al-4V lattice structures have found important niche applications. However, they often show insufficient compressive ductility or insufficient structural integrity. In this study, a batch of 45 octahedral Ti-6Al-4V lattice structures was manufactured in three different strut diameters (0.5, 1.0, 1.5 mm) by selective electron beam melting (SEBM). The influence of post-SEBM annealing on the compressive deformation characteristics of the lattice structure was investigated. The as-built Ti-6Al-4V lattices fragmented when the compressive strain reached 13%–23% depending on strut diameter. Annealing at 950 °C (β transus temperature: 995 °C) only slightly improved the compressive ductility of the lattice structures. However, annealing at 1050 °C (β-annealing) fundamentally changed the compressive deformation mode of the lattice structures. The resultant compressive stress-strain curve was featured by a long smooth plateau and no facture occurred even after significant densification of the lattice structure had taken place (>50% of compressive strain).