Imperial College London
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DrCraigBuchanan

Faculty of Engineering, Department of Civil and Environmental Engineering

Senior Lecturer
 
 
 
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Contact

 

+44 (0)20 7594 8076craig.buchanan

 
 
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Location

 

247Skempton BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Zhang:2021:10.1016/j.matdes.2021.109921,
author = {Zhang, R and Buchanan, C and Matilainen, V-P and Daskalaki-Mountanou, D and Britton, T and Piili, H and Salminen, A and Gardner, L},
doi = {10.1016/j.matdes.2021.109921},
journal = {Materials and Design},
pages = {1--20},
title = {Mechanical properties and microstructure of additively manufactured stainless steel with laser welded joints},
url = {http://dx.doi.org/10.1016/j.matdes.2021.109921},
volume = {208},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Powder bed fusion (PBF) is a commonly employed metal additive manufacturing (AM) process in which components are built, layer-by-layer, using metallic powder. The component size is limited by the internal build volume of the employed PBF AM equipment; the fabrication of components larger than this volume therefore requires mechanical joining methods, such as laser welding. There are, however, very limited test data on the mechanical performance of PBF metal with laser welded joints. In this study, the mechanical properties of PBF built 316L stainless steel parts, joined together using laser welding to form larger components, have been investigated; the microstructure of the components has also been examined. 33 PBF 316L stainless steel tensile coupons, with central laser welds, welded using a range of welding parameters, and with coupon half parts built in two different orientations, were tested. The porosity, microhardness and microstructure of the welded coupons, along with the widths of the weld and heat-affected zone (HAZ), were characterised. The PBF base metal exhibited a typical cellular microstructure, while the weld consisted of equiaxed, columnar and cellular dendrite microstructures. Narrow weld regions and HAZs were observed. The PBF base metal was found to have higher proof and ultimate strengths, but a similar fracture strain and a lower Young’s modulus, compared with conventionally manufactured 316L stainless steel. The strengths were dependent on the build direction – the vertically built specimens showed lower proof strengths than the horizontal specimens. The laser welds generally exhibited lower microhardness, proof strengths and fracture strains than the PBF base metal which correlated with the observed structure. This work has demonstrated that PBF built parts can be joined by laser welding to form larger components and provided insight into the resulting strength and ductility.
AU  - Zhang,R
AU  - Buchanan,C
AU  - Matilainen,V-P
AU  - Daskalaki-Mountanou,D
AU  - Britton,T
AU  - Piili,H
AU  - Salminen,A
AU  - Gardner,L
DO  - 10.1016/j.matdes.2021.109921
EP  - 20
PY  - 2021///
SN  - 0264-1275
SP  - 1
TI  - Mechanical properties and microstructure of additively manufactured stainless steel with laser welded joints
T2  - Materials and Design
UR  - http://dx.doi.org/10.1016/j.matdes.2021.109921
UR  - https://www.sciencedirect.com/science/article/pii/S0264127521004743
UR  - http://hdl.handle.net/10044/1/90247
VL  - 208
ER  -
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