Influence of Electron Beam Powder Bed Fusion Process Parameters on Transformation Temperatures and Pseudoelasticity of Shape Memory Nickel TitaniumShow others and affiliations
2023 (English)In: Advanced Engineering Materials, ISSN 1438-1656, E-ISSN 1527-2648, Vol. 25, no 12, article id 2201818Article in journal (Refereed) Published
Abstract [en]
Electron beam powder bed fusion (PBF-EB) is used to manufacture dense nickel titanium parts using various parameter sets, including the beam current, scan speed, and postcooling condition. The density of manufactured NiTi parts is investigated in relation to the linear energy input. The results imply that the part density increases with increasing linear energy density to over 98% of the bulk density. With a constant energy input, a combination of low power and low scan speed leads to denser parts. This is attributed to lower electrostatic repulsive forces from lower number density of the impacting electrons. After manufacturing, the densest parts with distinct parameter sets are categorized into three groups: 1) high power with high scan speed and vacuum slow cooling, 2) low power with low scan speed and vacuum slow cooling, and 3) low power with low scan speed and medium cooling rate in helium gas. Among these, a faster cooling rate suppresses phase transformation temperatures, while vacuum cooling combinations do not affect the phase transformation temperatures significantly. Herein, all the printed parts exhibit almost 8% pseudoelasticity regardless of the process parameters, while the parts cooled in helium have a higher energy dissipation efficiency (1 − η), which implies faster damping of oscillations. © 2023 The Authors. Advanced Engineering Materials published by Wiley-VCH GmbH.
Place, publisher, year, edition, pages
2023. Vol. 25, no 12, article id 2201818
Keywords [en]
cooling rate, mechanical property, NiTi, PBF-EB, process parameter, Binary alloys, Cooling, Electron beams, Energy dissipation, Helium, Nickel, Cooling rates, Electron-beam, Energy inputs, Linear energy, Low Power, Parameter set, Powder bed, Process parameters, Scan speed, Titanium alloys
National Category
Metallurgy and Metallic Materials
Identifiers
URN: urn:nbn:se:du-45976DOI: 10.1002/adem.202201818ISI: 000975548500001Scopus ID: 2-s2.0-85154049056OAI: oai:DiVA.org:du-45976DiVA, id: diva2:1755444
2023-05-082023-05-082023-09-25Bibliographically approved