Improved plasticity of Inconel 718 superalloy fabricated by selective laser melting through a novel heat treatment process
When Inconel 718 alloy is fabricated by selective laser melting and treated by traditional homogenization plus double aging heat treatment (HA), its strength improves greatly, but ductility decreases. A novel heat treatment (NHT) including higher temperature homogenization at 1150 °C for 2 h and one...
Main Authors: | , , , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
Elsevier
2019-10-01
|
Series: | Materials & Design |
Online Access: | http://www.sciencedirect.com/science/article/pii/S0264127519303533 |
id |
doaj-cebb7fdf61294773beae71b2123fb445 |
---|---|
record_format |
Article |
spelling |
doaj-cebb7fdf61294773beae71b2123fb4452020-11-25T01:40:27ZengElsevierMaterials & Design0264-12752019-10-01180Improved plasticity of Inconel 718 superalloy fabricated by selective laser melting through a novel heat treatment processX. Li0J.J. Shi1G.H. Cao2A.M. Russell3Z.J. Zhou4C.P. Li5G.F. Chen6State Key Laboratory of Advanced Special Steel and School of Materials Science and Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, ChinaState Key Laboratory of Advanced Special Steel and School of Materials Science and Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, ChinaState Key Laboratory of Advanced Special Steel and School of Materials Science and Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, China; Corresponding author.Department of Materials Science and Engineering, Iowa State University and Division of Materials Science and Engineering, Ames Laboratory of the U.S.D.O.E., Ames, IA 50011-2300, USAMaterials & Manufacturing Qualification Group, Corporate Technology, Siemens Ltd., China, Beijing 100102, ChinaMaterials & Manufacturing Qualification Group, Corporate Technology, Siemens Ltd., China, Beijing 100102, ChinaMaterials & Manufacturing Qualification Group, Corporate Technology, Siemens Ltd., China, Beijing 100102, ChinaWhen Inconel 718 alloy is fabricated by selective laser melting and treated by traditional homogenization plus double aging heat treatment (HA), its strength improves greatly, but ductility decreases. A novel heat treatment (NHT) including higher temperature homogenization at 1150 °C for 2 h and one-time lower temperature aging treatment at 700 °C for 12 h is developed, which can overcome the strength-plasticity trade-off of Inconel 718 alloy. The results show that recrystallized grains with annealing twins and ultrafine strengthening phases form in the specimen subjected to the NHT. These microstructures differ from those in as-built and conventional heat-treated samples. Especially the morphology of strengthening phase γ″-Ni3Nb precipitated in the NHT specimen has changed a lot, it seems to be spherical rather than disc-like shape occurred in the traditional heat-treated samples. Consequently, the NHT process increases plasticity by 41%, while maintaining ultimate strength at the same level achieved by the traditional heat treatment. The enhanced ductility is attributed to the annealing twins and recrystallized grains without local strains, while the strength is provided by the smaller precipitates formed in the NHT one-time aging treatment. Keywords: Inconel 718, Selective laser melting, Heat treatment, Plasticity, Annealing twinshttp://www.sciencedirect.com/science/article/pii/S0264127519303533 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
X. Li J.J. Shi G.H. Cao A.M. Russell Z.J. Zhou C.P. Li G.F. Chen |
spellingShingle |
X. Li J.J. Shi G.H. Cao A.M. Russell Z.J. Zhou C.P. Li G.F. Chen Improved plasticity of Inconel 718 superalloy fabricated by selective laser melting through a novel heat treatment process Materials & Design |
author_facet |
X. Li J.J. Shi G.H. Cao A.M. Russell Z.J. Zhou C.P. Li G.F. Chen |
author_sort |
X. Li |
title |
Improved plasticity of Inconel 718 superalloy fabricated by selective laser melting through a novel heat treatment process |
title_short |
Improved plasticity of Inconel 718 superalloy fabricated by selective laser melting through a novel heat treatment process |
title_full |
Improved plasticity of Inconel 718 superalloy fabricated by selective laser melting through a novel heat treatment process |
title_fullStr |
Improved plasticity of Inconel 718 superalloy fabricated by selective laser melting through a novel heat treatment process |
title_full_unstemmed |
Improved plasticity of Inconel 718 superalloy fabricated by selective laser melting through a novel heat treatment process |
title_sort |
improved plasticity of inconel 718 superalloy fabricated by selective laser melting through a novel heat treatment process |
publisher |
Elsevier |
series |
Materials & Design |
issn |
0264-1275 |
publishDate |
2019-10-01 |
description |
When Inconel 718 alloy is fabricated by selective laser melting and treated by traditional homogenization plus double aging heat treatment (HA), its strength improves greatly, but ductility decreases. A novel heat treatment (NHT) including higher temperature homogenization at 1150 °C for 2 h and one-time lower temperature aging treatment at 700 °C for 12 h is developed, which can overcome the strength-plasticity trade-off of Inconel 718 alloy. The results show that recrystallized grains with annealing twins and ultrafine strengthening phases form in the specimen subjected to the NHT. These microstructures differ from those in as-built and conventional heat-treated samples. Especially the morphology of strengthening phase γ″-Ni3Nb precipitated in the NHT specimen has changed a lot, it seems to be spherical rather than disc-like shape occurred in the traditional heat-treated samples. Consequently, the NHT process increases plasticity by 41%, while maintaining ultimate strength at the same level achieved by the traditional heat treatment. The enhanced ductility is attributed to the annealing twins and recrystallized grains without local strains, while the strength is provided by the smaller precipitates formed in the NHT one-time aging treatment. Keywords: Inconel 718, Selective laser melting, Heat treatment, Plasticity, Annealing twins |
url |
http://www.sciencedirect.com/science/article/pii/S0264127519303533 |
work_keys_str_mv |
AT xli improvedplasticityofinconel718superalloyfabricatedbyselectivelasermeltingthroughanovelheattreatmentprocess AT jjshi improvedplasticityofinconel718superalloyfabricatedbyselectivelasermeltingthroughanovelheattreatmentprocess AT ghcao improvedplasticityofinconel718superalloyfabricatedbyselectivelasermeltingthroughanovelheattreatmentprocess AT amrussell improvedplasticityofinconel718superalloyfabricatedbyselectivelasermeltingthroughanovelheattreatmentprocess AT zjzhou improvedplasticityofinconel718superalloyfabricatedbyselectivelasermeltingthroughanovelheattreatmentprocess AT cpli improvedplasticityofinconel718superalloyfabricatedbyselectivelasermeltingthroughanovelheattreatmentprocess AT gfchen improvedplasticityofinconel718superalloyfabricatedbyselectivelasermeltingthroughanovelheattreatmentprocess |
_version_ |
1725045668008951808 |