Microstructure and hydrogen embrittlement of additively manufactured Ti-6Al-4V

• Main Author: Neikter, Magnus
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Luleå tekniska universitet, Materialvetenskap 2019
• Subjects: Ti-6Al-4V; Additive Manufacturing; Texture; Microstructure; Hydrogen Embrittlement; Materials Chemistry; Materialkemi; Other Materials Engineering; Annan materialteknik; Skat; Trollhättan; Luleå
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-73905

The work of this doctoral thesis has been performed between the 24th of August 2015 to the 6th of September 2019. The general purpose of this work has been to increase the knowledge of additively manufactured Ti-6Al-4V when it comes to microstructure, texture and hydrogen embrittlement. Several additive manufacturing (AM) processes have been addressed, the main focus, however, has been on the two processes electron beam melting (EBM) and selective laser melting (SLM). The work has been performed at Luleå University of Technology and at Monash Centre of Additive Manufacturing (MCAM), which is a part of Monash University, Melbourne Australia. GKN Aerospace Engine Systems has been involved in the work as a collaborative industrial partner. Where the main interaction and support has been between GKN in Trollhättan, Sweden. GKNs facility in Filton, United Kingdom, however, has also been involved in sample production. The texture measurements using neutron time of flight (TOF) diffraction were performed in Dubna, Russia at Frank Laboratory of Neutron Physics at the Joint Institute for Nuclear Research, using the spektrometer kolitshestvennovo analiza tekstury (SKAT) instrument and in Los Alamos at Los Alamos Neutron Science Center, using the texture instrument high pressure preferred orientation (HIPPO). The interest of specifically additively manufactured Ti-6Al-4V originates from GKN Aerospace Engine Systems as they have been contracted to manufacture parts for the Ariane rockets. In aerospace, weight is of utter importance as reduced weight of the components reduce the fuel costs and makes it possible to transport increased loads. Therefore, titanium has been suggested to replace heavier metal alloys (such as nickel-based superalloys) due to titanium’s high specific strength and overall good properties. The work has been managed under the supervision of Professor Marta-Lena Antti, Professor Robert Pederson and Dr. Pia Åkerfeldt at Luleå University of Technology and by Professor Xinhua Wu and Professor Aijun Huang ...