Microstructural inhomogeneity and anisotropicproperties in IN-718 structures fabricated byElectron Beam Melting: Mikrostrukturell inhomogenitet och anisotropa egenskaper i strukturerav IN-718 tillverkade genom Electron Beam Melting
2017 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
Student thesisAlternative title
Mikrostrukturell inhomogenitet och anisotropa egenskaper i strukturerav IN-718 tillverkade genom Electron Beam Melting (Swedish)
Abstract [en]
Additive Manufacturing, or 3D printing, provides an opportunity to manufacture advanced 3D geometrieswith little material waste and reduced need for tooling compared to conventional methods. There are,however, challenges remaining regarding anisotropy in the mechanical properties of built components.
The aim of this project is to investigate the anisotropy of additive manufactured material and the effect ofdifferent build directions. The material used is Inconel 718, which was manufactured by Electron BeamMelting as vertical and horizontal rods. The tests performed are microstructural investigations about thegrains, precipitates and porosities, but also include hardness testing and tensile testing. The material istested in its as-built state.
The results show that the material consist of an anisotropic microstructure with elongated grains in thebuild direction. The build height has a bigger influence on the properties of the material than the builddirection for the specimens. The top pieces are consistently different from the others and are the leasthomogeneous. The microstructure consists of large quantities of delta-phase, and solidification pores arefound throughout the material. The hardness of the material differs from 324 HV to 408 HV depending onthe part of the build. The tensile testing shows that the vertically built specimens have a higher yieldstrength and ultimate tensile strength while the horizontally built specimens have a greater ductility.
Place, publisher, year, edition, pages
2017. , p. 47
Keywords [en]
AM EBM IN-718 Inconel 718 Electron Beam Melting 3d-printing superalloy
National Category
Metallurgy and Metallic Materials Manufacturing, Surface and Joining Technology
Identifiers
URN: urn:nbn:se:liu:diva-138202ISRN: LIU-IEI-TEK-A--17/02739—SEOAI: oai:DiVA.org:liu-138202DiVA, id: diva2:1109150
Subject / course
Engineering Materials
Presentation
2017-05-30, 08:04 (English)
Supervisors
Examiners
2017-06-202017-06-132023-12-28Bibliographically approved