Deformation and failure mechanisms of Ti–6Al–4V as built by selective laser melting
Name
1905.12754.pdf
Description
Accepted version
Size
2.53 MB
Format
Adobe PDF
Checksum (MD5)
66cea8d6040dda64286fe39545379679
Author(s)
Moridi, Atieh
Demir, Ali Gökhan
Caprio, Leonardo
Hart, A John
Previtali, Barbara
Colosimo, Bianca M
Date Issued
2019
Journal
Materials Science and Engineering A
Publisher
Elsevier BV
Version
Author's final manuscript
Abstract
The ability to create complex geometries with tailored material properties has brought interest in using additive manufacturing (AM) techniques for many industrial applications. However, further understanding of the complex relationship between AM process parameters, microstructure, and resultant properties is critical for the widespread use of metal AM. In this study, selective laser melting (SLM) is used to print Ti–6Al–4V. Tensile tests with concurrent microstructural analysis using electron backscatter diffraction, electron channeling contrast imaging, and digital image correlation are performed to understand the damage and its relation to the microstructure of Ti–6Al–4V after SLM processing. We find that the as-printed Ti–6Al–4V shows hierarchical microstructures, consisting of primary, secondary, and tertiary α martensite. This hierarchical structure is formed as a result of cyclic heat treatment during the layer-wise SLM process. Upon tensile deformation, strain localization within primary α martensite results in microscopic ductile micro-void formation and coalescence, as well as macroscopic brittle fracture. In addition to localization inside primary α , surface steps at the boundaries of these high aspect ratio grains are formed which reveal the contribution of interfacial plasticity to the overall deformation of the material. ' ' '
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Massachusetts Institute of Technology. Laboratory for Manufacturing and Productivity
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivs License
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1016/J.MSEA.2019.138456
