Abstract
Additive manufactured (AM) materials exhibit enhanced performance, while post-processing is essential to reinforce its properties. Controlling the tunable factors and the underlying strengthening mechanisms during the post-processing are a key to answering the calls from the industry and end users. We identified the principal strengthening factors that contribute to AM stainless steel under heat-treatment and weighed their importance. The as-built sample exhibited a unique microstructure with a heterogeneous grain size distribution, a small amount of retained austenite, high dislocation density, and dispersed oxide particles. The strengthening primarily by dislocation forest and additionally by heterogeneous grain size contributed to the as-built sample. Although aging slightly decreased dislocation strengthening, superior aging enhancement was achieved by Cu-precipitates. The solid-solutionizing not only increased the effective grain size but also reduced the dislocation density by eliminating the heterogeneous microstructure, which deteriorated the precipitation hardenability. Our findings shed light on the performance optimization of AM metals.
| Original language | English |
|---|---|
| Article number | 111645 |
| Journal | Materials Characterization |
| Volume | 184 |
| DOIs | |
| State | Published - Feb 2022 |
Funding
This work was supported by a National Research Foundation (NRF) grant funded by the Korean Government (2020M2A2A6A05026873, 2017M2A2A6A05017653, 2020K1A3A7A09078090, 2021R1A4A1031494). A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. We sincerely appreciate Prof. Tamás Ungár for guiding the Convolutional Multiple Whole Profile (CMWP) software. EWH and MYL are grateful to the support of the Ministry of Science and Technology (MOST) Program 108-2221-E-009-131-MY4 & 110-2224-E-007-001, Industrial Technology Research Institute (ITRI) 109A502, and financial support from the “High Entropy Materials Center” from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan. EWH and MYL were financially supported by the “Center for the Semiconductor Technology Research” from the Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by MOE in Taiwan, which is also supported in part by the Ministry of Science and Technology, Taiwan, under Grant MOST-109-2634-F-009-029. This work was supported by a National Research Foundation (NRF) grant funded by the Korean Government ( 2020M2A2A6A05026873 , 2017M2A2A6A05017653 , 2020K1A3A7A09078090 , 2021R1A4A1031494 ). A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. We sincerely appreciate Prof. Tamás Ungár for guiding the Convolutional Multiple Whole Profile (CMWP) software. EWH and MYL are grateful to the support of the Ministry of Science and Technology (MOST) Program 108-2221-E-009-131-MY4 & 110-2224-E-007-001 , Industrial Technology Research Institute (ITRI) 109A502 , and financial support from the “High Entropy Materials Center” from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan. EWH and MYL were financially supported by the “Center for the Semiconductor Technology Research” from the Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by MOE in Taiwan, which is also supported in part by the Ministry of Science and Technology, Taiwan , under Grant MOST-109-2634-F-009-029 .
Keywords
- Additive manufacturing
- Heat-treatment
- Neutron scattering
- Stainless steel
- Strengthening
