Anisotropic tensile behaviour of additively manufactured Ti-6Al-4V simulated with crystal plasticity. (November 2021)

• Record Type: Journal Article
• Authors: Somlo, K.; Poulios, K.; Funch, C.V.; Niordson, C.F.
• Is Part Of: Mechanics of materials. Volume 162(2021)
• Publication Date: 2021-11
• Subjects: Crystal plasticity -- Anisotropy -- Titanium alloy -- Crystallographic texture -- Tensile behaviour; Strength of materials -- Periodicals; Mechanics, Applied -- Periodicals; Résistance des matériaux -- Périodiques; Mécanique appliquée -- Périodiques; Mechanics, Applied; Strength of materials; Periodicals; Electronic journals; 620.11
• DOI: 10.1016/j.mechmat.2021.104034
• Languages: English
• ISSNs: 0167-6636

Abstract

Abstract: The anisotropic behaviour of laser powder bed fusion (LPBF) Ti-6Al-4V under uniaxial tension is investigated through crystal plasticity simulations. A periodic multi-scale representative volume element (RVE) is calibrated against quasi-static tensile tests carried out on dog-bone specimens, printed in different orientations. This fitting procedure results in an anisotropic crystallographic texture and a minimum set of crystal plasticity constitutive parameters which are able to reproduce the experimental behaviour. The synthetic RVE consists of primary grains with a realistic aspect ratio and an internal lamellar structure, that approximates the α ′ martensite microstructure observed in micrographs of as-built Ti-6Al-4V. The Young's modulus, yield strength, and hardening behaviour observed experimentally, could be precisely captured using a very limited number of model parameters. Thereby, this work contributes to a deeper understanding of the interplay between micro-structure and macroscopic behaviour, and with a new set of crystal plasticity parameters specific for α ′ dominated LPBF Ti-6Al-4V. Graphical abstract: Highlights: LPBF Ti-6Al-4V exhibits elastic and plastic anisotropy. Multi-scale periodic RVE is applied consisting hexagonal crystals with synthetic texture. Crystal plasticity simulations can fit experimentally observed anisotropy. The simulations require relatively high CRSS values and usual elastic parameters.