Room Temperature Deformation Mechanisms of Alumina Particles Observed from In Situ Micro-compression and Atomistic Simulations
| Autor: | Jay Carroll, William M. Mook, Khalid Hattar, Aaron Christopher. Hall, Pylin Sarobol, Daniel Charles Bufford, Michael Chandross, Paul G. Kotula, Brad L. Boyce |
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| Rok vydání: | 2015 |
| Předmět: |
010302 applied physics
Materials science Scanning electron microscope technology industry and agriculture Nucleation 02 engineering and technology Plasticity Nanoindentation 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Surfaces Coatings and Films Condensed Matter::Materials Science Deformation mechanism visual_art 0103 physical sciences Materials Chemistry visual_art.visual_art_medium Grain boundary Ceramic Dislocation Composite material 0210 nano-technology |
| Zdroj: | Journal of Thermal Spray Technology. 25:82-93 |
| ISSN: | 1544-1016 1059-9630 |
| DOI: | 10.1007/s11666-015-0295-2 |
| Popis: | Aerosol deposition (AD) is a solid-state deposition technology that has been developed to fabricate ceramic coatings nominally at room temperature. Sub-micron ceramic particles accelerated by pressurized gas impact, deform, and consolidate on substrates under vacuum. Ceramic particle consolidation in AD coatings is highly dependent on particle deformation and bonding; these behaviors are not well understood. In this work, atomistic simulations and in situ micro-compressions in the scanning electron microscope, and the transmission electron microscope (TEM) were utilized to investigate fundamental mechanisms responsible for plastic deformation/fracture of particles under applied compression. Results showed that highly defective micron-sized alumina particles, initially containing numerous dislocations or a grain boundary, exhibited no observable shape change before fracture/fragmentation. Simulations and experimental results indicated that particles containing a grain boundary only accommodate low strain energy per unit volume before crack nucleation and propagation. In contrast, nearly defect-free, sub-micron, single crystal alumina particles exhibited plastic deformation and fracture without fragmentation. Dislocation nucleation/motion, significant plastic deformation, and shape change were observed. Simulation and TEM in situ micro-compression results indicated that nearly defect-free particles accommodate high strain energy per unit volume associated with dislocation plasticity before fracture. The identified deformation mechanisms provide insight into feedstock design for AD. |
| Databáze: | OpenAIRE |
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