Abstract
Additive manufacturing (AM) of H13 tool steel by binder jet 3D printing (BJ3DP) followed by pressureless supersolidus liquid phase sintering (SLPS) provides a low-cost alternative manufacturing method for components with intricate geometric features. However, the microstructure-mechanical property relationships for BJ3DP-SLPS produced H13 tool steel are not well understood, which makes it challenging to develop printing and post-processing methods that maximize part performance. In this work, we leverage atom probe tomography and transmission electron microscopy along with thermodynamic calculations to rationalize the microstructure-mechanical property relationships in as-sintered BJ3DP H13 tool steel. We report for the first time, the presence of a continuous eutectic film-like carbide in H13 along with the more commonly observed cuboidal MX carbides in the prior liquid channels of the microstructure. Further, atom probe tomography revealed the interconnected nature of the MX carbides that appear to be discrete in two-dimensional micrographs. These continuous eutectic carbides and interconnected MX carbides result in brittle failure of the material. Characterization of these microstructural features will be critical in developing appropriate post-processing heat treatments for the improved mechanical performance of BJ3DP H13.
| Original language | English |
|---|---|
| Article number | 102834 |
| Journal | Additive Manufacturing |
| Volume | 56 |
| DOIs | |
| State | Published - Aug 2022 |
Funding
This work was supported by Department of Energy Vehicle Technology Office as a part of powertrain materials core program. The FIB preparation of APT samples and APT analysis was conducted using facilities at Environmental Molecular Sciences Laboratory (EMSL) which is a national user facility located at PNNL. EMSL is supported by DOE Biological and Environmental Research (BER) program. The materials processing, mechanical tests and modeling were performed at the U.S. Department of Energy's Manufacturing Demonstration Facility, located at Oak Ridge National Laboratory. This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05–00OR22725 with the U.S. Department of Energy. Research was co-sponsored by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Office and Vehicle Technologies Office as a part of powertrain Materials core Program.
Keywords
- Atom probe tomography
- Binder jet additive manufacturing
- H13 tool steel
- Microstructure
- Sintering
