In situ X-ray imaging of hot cracking and porosity during LPBF of Al-2139 with TiB2 additions and varied process parameters

DOI: 10.1016/j.matdes.2023.112031

Authors: David T. Rees (University College London; Research Complex at Harwell) , Chu Lun Alex Leung (University College London; Research Complex at Harwell) , Joe Elambasseril (RMIT University) , Sebastian Marussi (University College London; Research Complex at Harwell) , Saurabh Shah (University College London; Research Complex at Harwell) , Shashidhara Marathe (Diamond Light Source) , Milan Brandt (RMIT University) , Mark Easton (RMIT University) , Peter D. Lee (University College London; Research Complex at Harwell)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Materials & Design , VOL 15

State: Published (Approved)
Published: June 2023
Diamond Proposal Number(s): 19354 , 22976

Abstract: Laser powder bed fusion (LPBF) additive manufacturing of 2XXX series Al alloys could be used for low volume specialist aerospace components, however, such alloys exhibit hot cracking susceptibility that can lead to component failure. In this study, we show two approaches to suppress the formation of hot cracks by controlling solidification behaviour using: (1) TiB2 additions; and (2) optimisation of LPBF process parameters. Using high-speed synchrotron X-ray radiography, we monitored LPBF of Al-2139 in situ, with and without TiB2 under a range of process conditions. In situ X-ray radiography results captured the crack growth over 1.0 ms at a rate of ca. 110 mm s-1, as well as pore evolution, wetting behaviour and build height. High-resolution synchrotron X-ray computed tomography (sCT) was used to measure the volume fraction of defects, e.g. hydrogen pores and microcracks, in the as-built LPBF samples. Our results show adding TiB2 in Al-2139 reduces the volume of cracks by up to 79 % under a volume energy density of 1000 to 5000 J mm-3, as well as reducing the average length, breadth, and surface area of cracks.

Journal Keywords: Additive manufacturing; Laser powder bed fusion; Aluminium alloys; X-ray imaging; Hot cracking

Diamond Keywords: Additive Manufacturing; Alloys

Subject Areas: Materials, Engineering


Instruments: I13-2-Diamond Manchester Imaging

Added On: 07/06/2023 09:49

Documents:
1-s2.0-S026412752300446X-main.pdf

Discipline Tags:

Materials Engineering & Processes Aerospace Materials Science Engineering & Technology Metallurgy

Technical Tags:

Imaging Tomography