Abstract
W-ZrC composites were successfully prepared by reactive melt infiltration (RMI) of stoichiometric and excess amounts of Zr2Cu into sintered and un-sintered WC preforms made from binder jet 3D printing. The focus of this work was to study the conversion of reactant powders and liquid infiltrant with varying preform density and infiltrant amount by controlling the processing time to reach high conversion yield while understanding the phase composition, microstructure, and hardness. To investigate the effect of time, the reactive melt infiltration was conducted at 1400 °C for 2, 4 and 8 h in a furnace with 96% Ar - 4% H2 gas atmosphere. The increase in reaction time from 2 to 8 h increased the W and W2C phase contents and decreased the ZrC phase content when using sintered WC preforms. Samples prepared from un-sintered WC preforms exhibited improved reactive melt infiltration compared to sintered samples, and there was no detectable W2C phase and nearly full consumption of WC. Similar to sintered WC samples, the content of W and ZrC phases increased with the increase in time from 2 to 8 h. The interfaces and phases at reaction interfaces were investigated using electron diffraction analysis and S/TEM-EDS to understand material stability; the phases were identified and consistent with XRD analysis. Additionally, there was no Cu present at the interfaces. Increasing the amount of infiltrant led to better reactive melt infiltration. In general, the hardness increased with reaction time and the highest Vickers hardness was found in the W-ZrC sample formed from sintered WC reacted with excess Zr2Cu. This research addresses the critical comparison of sintering and RMI time and shows that by using un-sintered samples for 8 h we are able to achieve W-ZrC composites with fewer undesired phases.
| Original language | English |
|---|---|
| Article number | 105411 |
| Journal | International Journal of Refractory Metals and Hard Materials |
| Volume | 94 |
| DOIs | |
| State | Published - Jan 2021 |
Funding
Microscopy research was supported by the Office of Nuclear Energy, Fuel Cycle R&D Program and the Nuclear Science User Facilities. The authors would like to acknowledge D.W. Coffey, Ercan Cakmak and Tom Geer at ORNL, and Sergey Yarmolenko at NCAT for assistance with the experimental work. This research was supported in part by an appointment to the Oak Ridge National Laboratory ASTRO Program, sponsored by the U.S. Department of Energy and administered by the Oak Ridge Institute for Science and Education. This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ) Microscopy research was supported by the Office of Nuclear Energy , Fuel Cycle R&D Program and the Nuclear Science User Facilities. The authors would like to acknowledge D.W. Coffey, Ercan Cakmak and Tom Geer at ORNL, and Sergey Yarmolenko at NCAT for assistance with the experimental work. This research was supported in part by an appointment to the Oak Ridge National Laboratory ASTRO Program, sponsored by the U.S. Department of Energy and administered by the Oak Ridge Institute for Science and Education .
| Funders | Funder number |
|---|---|
| NCAT | |
| U.S. Department of Energy | |
| Oak Ridge National Laboratory | |
| Oak Ridge Institute for Science and Education |
Keywords
- Binder jet
- Metal-ceramic composites
- Reactive melt infiltration
- Tungsten
- Zirconium carbide