| About this Abstract |
| Meeting |
Materials Science & Technology 2020
|
| Symposium
|
Additive Manufacturing of Metals: Complex Microstructures and Architecture Design
|
| Presentation Title |
Microstructural Features and Mechanical Properties of a Newly Designed Steel Fabricated by Laser Powder Bed Fusion |
| Author(s) |
Yuan Tian, Robert Palad, Clodualdo Jr. Aranas |
| On-Site Speaker (Planned) |
Robert Palad |
| Abstract Scope |
A new iron-based alloy, M789, with good printability and corrosion resistance has been recently developed and additively manufactured by laser power bed fusion process. The relationship between the microstructural features and the mechanical properties of M789 steel was studied and evaluated. In the as-printed condition, epitaxial grain growth of cellular dendritic structure inside the melt pool was observed. The primary dendrite arm spacing was measured to be 0.42±0.12 µm. The electron backscatter diffraction maps suggest the formation of elongated columnar grains with significant low-angle grain boundaries. In the solution annealed and aged samples, melt pool boundaries and scan tracks disappeared; large needle-like martensitic structures were evident with fewer LAGBs. Moreover, spherical ETA-Ni3Ti precipitates were formed during the heat-treated process, which led to significant increase in hardness, tensile and yield strength with values of 52.4±0.7HRC, 1798±4MPa and 1714±13MPa, respectively. Thermodynamic and mechanical properties simulation were consistent with the experimental data. |