Manufacturing size effect on the structural and mechanical properties of additively manufactured Ti-6Al-4V microbeams. (20th June 2023)

• Record Type: Journal Article
• Authors: Yin, Kaiyang; Cao, Bo; Todt, Juraj; Gutmann, Florian; Tunçay, Hasan Furkan; Roth, Antonina; Fischer, Frank; Grübel, Nadira; Pfaff, Aron; Ganzenmüller, Georg C.; Keckes, Jozef; Hiermaier, Stefan; Eberl, Christoph
• Is Part Of: Journal of materials science & technology. Volume 149(2023)
• Page Start: 18
• Page End: 30
• Publication Date: 2023-06-20
• Subjects: Selected laser melting -- Porosity -- Texture -- Epitaxial growth -- Finite element modeling -- Metallic mechanical metamaterials; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2022.12.006
• Languages: English
• ISSNs: 1005-0302

Abstract

Highlights: Linearly decreasing porosities at an increasing diameter of from 250 to 500 μm; pores located mostly between the contour and the hatch infill. Increasing α-Ti texture at an increasing diameter of the microbeams due to the increasing size of large central crystal domains originated from a single or very few parent β-Ti grains. Increasing Young's modulus and UTS increases at an increasing diameter of the microbeams slightly due to the increasing texture towards the crystal orientation with a higher modulus, and the decreasing pore volume ratio and surface-to-volume ratio of the microbeams, respectively. High yield strength/E ratio of Ti-6Al-4V structures manufactured by selected laser melting, attractive as elements for metallic mechanical metamaterials, in particular in this study the 375 μm diameter microbeams. Graphical abstract: Abstract: The size effect of Ti-6Al-4V submillimeter structures manufactured by selective laser melting, which is critical for metallic mechanical metamaterials of unique mechanical properties, for example, negative Poisson's ratio and ultrahigh modulus, which show promise in biomedical, environmental, energy-related applications, has not been systematically investigated. Presented here are the quantification of the porosities by X-ray microtomography scans, texture analysis, and mechanical characterization of the additively manufactured Ti-6Al-4V microbeams. We found linearly decreasing porosities, increasing mechanical properties, and increasing texture in the microbeam with increasing diameter from 250 to 500 µm. The variation of microstructure in microbeams of different diameters and along the sample height, resulting from the printing parameters and the thermal conditions, leads to the discrepancy between the behavior observed in experiments and finite element simulation. Our results provide the structure-property-processing correlation to improve the manufacturing and prediction of the mechanical behavior of metallic mechanical metamaterials.