A5101830922- Metallic Glasses and Amorphous Alloys
- Material Dynamics and Properties
- Glass properties and applications
- Nuclear Materials and Properties
- Theoretical and Computational Physics
- Quasicrystal Structures and Properties
- Additive Manufacturing Materials and Processes
- Mineralogy and Gemology Studies
- Phase-change materials and chalcogenides
- High-Temperature Coating Behaviors
- Fusion materials and technologies
- Nuclear materials and radiation effects
- Ion-surface interactions and analysis
- Microstructure and mechanical properties
Oregon State University
2019-2024
Titanium-based metallic glasses (TBMGs) are attracting broad interest due to their simultaneous light weight, superhigh strength, and specific exceptional wear- corrosion-resistance biocompatibility, desirable for electronic, biomedical, aerospace applications. However, the glass-forming ability (GFA) of TBMGs, except some containing significant amount toxic (Be) or precious (Pd, Ag) elements, is disappointingly low, as manifested by a critical casting diameter (dc) not more than 6 mm, which...
Oxide-dispersion-strengthened (ODS) steels have long been viewed as a prime solution for harsh environments. However, conventional manufacturing of ODS limits the final product geometry, is difficult to scale up large components, and expensive due multiple highly involved, solid-state processing steps required. Additive (AM) can directly incorporate dispersion elements (e.g., Y, Ti O) during component fabrication, thus bypassing need an steel supply chain, scale-up challenges powder routes,...
Multicomponent metallic glasses (MGs) are a fascinating class of advanced alloys known for their exceptional properties such as limit-approaching strength, high hardness and corrosion resistance, near-net-shape castability. One important question regarding these materials that remains unanswered is how the different elements atomic bonds within them control strength deformability. Here, we present detailed visual statistical analysis behaviors various in Zr
Laser Powder Bed Fusion (LPBF) enables the efficient production of near-net-shape oxide dispersion-strengthened (ODS) alloys, which possess superior mechanical properties due to nanoparticles (e.g., yttrium oxide, Y-O, and yttrium-titanium Y-Ti-O) embedded in alloy matrix. To better understand precipitation mechanisms predict their size distribution under LPBF conditions, we developed an innovative physics-based multiscale modeling strategy that incorporates multiple computational...
Current understanding of the origin icosahedral clusters or short-range ordering in undercooled metallic liquids glasses is based on Frank's consideration an isolated icosahedron whose core has lower potential energy than shell. Using large scale atomistic simulations and statistical analysis several bcc (body-centered-cubic) fcc (face-centered-cubic) metals, here we show that shells icosahedrons spontaneously formed inside deeply fact have (averaged) cores. The shell deficiency occurs only...
Understanding crystallization mechanisms in nano-sized metallic glasses (MGs) is important to the manufacturing and application of these new nanomaterials that possess a unique combination structural functional properties. Due two-dimensional projections limited spatial and/or temporal resolutions experiments, significant questions (e.g., whether nucleation takes place on free surface or near-surface layer) regarding this subject remain under debate. Here, we address outstanding using...
While most studies have considered diffusion in metallic glasses (MGs) to be normal, with a temporally asymptotic diffusivity at given temperature (T), we report that the is anomalous and should described as subdiffusion pure Ta V MGs—two examples chosen here because of chemical simplicity, fast relaxation, minimal ambiguity. The constant T (below glass transition temperature) drops continuously time t according negative power law instead commonly assumed exponential decay. To understand...
Pure metals so far have been obtained in quasicrystal (QC) forms only by templation – epitaxial growth on a QC substrate. Here, we report spontaneous formation of dodecagonal (DDQC) grains pure tantalum (Ta), an early transition metal normally body-centered-cubic crystal structure. The DDQC comprise icosahedral clusters assembled accordance with the Stampfli triangle–square tiling scheme and are formed directly from supercooled liquid β-Ta phases during thermal devitrification Ta metallic...
Stacking fault tetrahedra (SFTs) are highly interesting three-dimensional vacancy defects in quenched, plastically deformed or irradiated face-centered-cubic metals and have a significant impact on the properties subsequent microstructural evolution of materials. Their formation mechanism stability relative to two-dimensional loops still debated. Equilateral hexagonal Frank (faulted, sessile) observed microscopy been considered unable directly transform SFTs due separation Shockley partial...