| Property | Ytterbium (Yb) | Aluminium (Al) |
|---|---|---|
| Atomic Radius | Large atomic radius (222 pm), significantly different from typical metallic elements | Small atomic radius (143 pm), aids in packing density but complicates alloying |
| Glass-Forming Ability (GFA) | Yb contributes to high GFA when paired with metals like Al, stabilizing amorphous phases due to deep eutectic compositions and minimal crystalline structures. | Al’s GFA is lower in isolation but increases significantly in alloys, especially when combined with rare-earth elements or transition metals. |
| Thermal Properties | High thermal stability in Yb-based alloys, with good glass transition temperatures (Tg) that resist crystallization at lower cooling rates. | Al-based amorphous alloys require high cooling rates but can provide high thermal conductivity in composites. |
| Mechanical Properties | Yb-based alloys demonstrate high elastic limits and yield strengths, making them suitable for high-stress applications. | Al-based glasses, while lightweight, tend to have lower mechanical strength compared to Yb-based alloys unless heavily alloyed. |
| Corrosion Resistance | Ytterbium oxides (Yb2O3) form passivating layers that enhance corrosion resistance, particularly in acidic environments. | Aluminium oxides (Al2O3) also provide corrosion resistance, but the effectiveness is contingent on alloy composition and environment. |
| Applications in Amorphous Steel | Yb contributes to improved toughness and higher glass-forming efficiency in amorphous steels, particularly in high-stress and temperature environments. | Al is commonly alloyed to reduce density and increase corrosion resistance, particularly in applications where weight is a critical factor. |
| Crystallization Behavior | Lower crystallization tendency in Yb-rich alloys due to the mismatch in atomic radii and favorable enthalpy of mixing with other metals. | Al alloys have a higher tendency to crystallize unless stabilized by specific alloying elements like Zr or lanthanides. |
Ytterbium enhances glass-forming ability, mechanical strength, and corrosion resistance in amorphous steel alloys, while aluminium primarily reduces weight and increases corrosion resistance.