Imperial College London
Portrait Picture

Dr T Ben Britton

Faculty of Engineering, Department of Materials

Visiting Reader
 
 
 
//

Contact

 

+44 (0)20 7594 2634b.britton Website

 
 
//

Location

 

B301Bessemer BuildingSouth Kensington Campus

//

Summary

 

Publications

Citation

BibTex format

@unpublished{Pedrazzini:2020,
author = {Pedrazzini, S and Pek, ME and Ackerman, AK and Ali, H and Ghadbeigi, H and Mumtaz, K and Dessolier, T and Britton, TB and Bajaj, P and Jägle, E and Gault, B and London, AJ and Galindo-Nava, E},
publisher = {arXiv},
title = {Influence of powder-bed temperature on the microstructure and mechanical  properties of Ti-6Al-4V produced by selective laser melting},
url = {http://arxiv.org/abs/2006.08288v1},
year = {2020}
}
Download

RIS format (EndNote, RefMan)

TY  - UNPB
AB  - Advanced characterisation techniques were used on LPBF Ti-6Al-4V samplesproduced on a heated base plate. When the substrate temperature is 100{\deg}Cthe elongation is 6\%, which increases and peaks at 10\% at 570{\deg}C, thensharply decreases to zero ductility at 770{\deg}C. At 100{\deg}C, a heavilystrained and twinned microstructure, primarily composed of {\alpha}+{\alpha}',was observed and it was comparable to asbuilt microstructures obtained byconventional LPBF methods. At higher temperatures, twins are no longer presentand instead nano-scale {\beta} precipitates are observed within {\alpha}' and{\alpha}, as well as dislocation networks (570{\deg}C) and tangles(770{\deg}C). Solute segregation at crystal defects was observed in allpre-heating conditions. Al and V segregation at microtwins was observed in the100{\deg}C sample, reporting for the first time `selective' and mutuallyexclusive Al- and V-rich regions forming in adjacent twins. V segregation atdislocations was observed in the 570{\deg}C and 770{\deg}C samples, consistentwith the higher preheating temperatures. High O contents were measured in allsamples but with apparent opposing effects. At 100{\deg}C and 570{\deg}C wasestimated to be below the critical threshold for O embrittlement and locallyaids in maintaining a strength high by solid solution strengthening, whereas at770{\deg}C it was above the threshold, therefore failing in a brittle fashion.Based on these observations, the initial increase in ductility from 100{\deg}Cto 570{\deg}C is attributed to a reduction in microtwins and the dislocationnetworks acting as `soft barriers' for slip within a coarser microstructure.The lack of ductility at 770{\deg}C was attributed to local soluteredistribution causing dislocation pinning and an increase of O content in thissample.
AU  - Pedrazzini,S
AU  - Pek,ME
AU  - Ackerman,AK
AU  - Ali,H
AU  - Ghadbeigi,H
AU  - Mumtaz,K
AU  - Dessolier,T
AU  - Britton,TB
AU  - Bajaj,P
AU  - Jägle,E
AU  - Gault,B
AU  - London,AJ
AU  - Galindo-Nava,E
PB  - arXiv
PY  - 2020///
TI  - Influence of powder-bed temperature on the microstructure and mechanical  properties of Ti-6Al-4V produced by selective laser melting
UR  - http://arxiv.org/abs/2006.08288v1
UR  - http://hdl.handle.net/10044/1/80018
ER  -
Download