Effects of heavy rare earth elements on properties of Fe41Co7Cr15Mo14C15B6RE2 41 Co 7 Cr 15 Mo 14 C 15 B 6 RE 2 (RE = Y, Lu, Tm, Tb) bulk metallic glasses

This study systematically explores the impact of different heavy rare earth (RE) elements (Y, Lu, Tm, Tb) on Fe41Co7Cr15Mo14C15B6RE2 41 Co 7 Cr 15 Mo 14 C 15 B 6 RE 2 BMGs bulk metallic glasses (BMGs), labeled A-Y, A-Lu, A-Tm, and A-Tb, respectively. These Fe-based BMGs, fabricated as rods (10 mm diameter) and plates (3 mm thickness) via copper mold suction casting, exhibit significant glass-forming ability. These BMGs exhibited high compressive strength (3.5 to 3.9 GPa) and Vickers microhardness (1260 to 1405 HV0.2), 0.2 ), with A-Lu, A-Tm, and A-Tb showing improved strength and hardness compared to A-Y. Electrochemical tests revealed superior corrosion resistance compared to stainless steels 316 and 304, particularly for A-Lu. X-ray photoelectron spectroscopy analysis suggests that the substitution of Lu and Tm for Y decreases unstable metal ion oxides, enhancing corrosion resistance. Additionally, Fe-based BMGs, especially A-Lu, demonstrated superior wear performance compared to conventional stainless steel 316, attributed to the formation of a protective oxide layer and high inherent hardness.