Enhanced near-infrared absorption for laser powder bed fusion using reduced graphene oxide

DOI: 10.1016/j.apmt.2021.101009

Authors: Chu Lun Alex Leung (University College London; Research Complex at Harwell) , Iuliia Elizarova (Imperial College London) , Mark Isaacs (Research Complex at Harwell; University College London) , Shashidhara Marathe (Diamond Light Source) , Eduardo Saiz (Imperial College London) , Peter D. Lee (University College London; Research Complex at Harwell)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Applied Materials Today , VOL 23

State: Published (Approved)
Published: June 2021
Diamond Proposal Number(s): 19354

Abstract: Laser powder bed fusion (LPBF) is a revolutionary manufacturing technology that fabricates parts with unparalleled complexity, layer-by-layer. However, there are limited choices of commercial powders for LPBF, constrained partly by the laser absorbance, an area that is not well investigated. Carbon additives are commonly used to promote near infra-red (NIR) absorbance of the powders but their efficiency is limited. Here, we combine operando synchrotron X-ray imaging with chemical characterisation techniques to elucidate the role of additives on NIR absorption, melt track and defect evolution mechanisms during LPBF. We employ a reduced graphene oxide (rGO) additive to enable LPBF of low NIR absorbance powder, SiO2, under systematic build conditions. This work successfully manufactured glass tracks with a high relative density (99.6%) and overhang features (> 5 mm long) without pre/post heat treatment. Compared to conventional carbon additives, the rGO increases the powder's NIR absorbance by ca. 3 times and decreases the warpage and porosity in LPBF glass tracks. Our approach will dramatically widen the palette of materials for laser processing and enable existing LPBF machines to process low absorbance powder, such as SiO2, using a NIR beam.

Journal Keywords: Absorption; Additive manufacturing; Defects; Consolidation; X-ray imaging

Diamond Keywords: Additive Manufacturing

Subject Areas: Materials


Instruments: I13-2-Diamond Manchester Imaging

Documents:
1-s2.0-S2352940721000743-main.pdf

Discipline Tags:

Material Sciences

Technical Tags:

Imaging Tomography