Regensburg 2025 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 20: Topical Session: Thermophysical Properties of Bulk Metallic Glasses and Bulk Metallic Glass-forming Liquids

MM 20.3: Vortrag

Mittwoch, 19. März 2025, 16:30–16:45, H10

Ni-Nb-(Ta)-P-Based Bulk Metallic Glasses: The Origin of Glass Formation Based on Thermodynamics, Kinetics, Structure and Crystallization Behavior — •Lucas M. Ruschel and Ralf Busch — Chair of Metallic Materials, Saarland University, 66123, Saarbrücken, Germany

Ni-Nb-based bulk glass-forming alloys are among the most promising amorphous metals for industrial applications due to their incomparable combination of strength, hardness, elasticity and plasticity. A successful approach in alloy development is so-called minor alloying, where metallic glasses with improved properties and enhanced GFA are produced, if the proper minor alloying element is chosen for the respective base alloy. Here, minor additions of P to the binary Ni-Nb system increase the GFA up to a record value of 5 mm, which surpasses the binary Ni62Nb38 alloy by 150 %. The partial substitution of Nb by Ta further boosts the GFA up to 6 mm. To elucidate the origins of the significant improvement in GFA, key properties such as the thermodynamics and kinetics of the system are studied, including the driving force for crystallization and the kinetic slowdown of viscosity during the transition from the equilibrium liquid to the glassy state. The primary precipitating phase, critical for glass formation, is identified by high-energy synchrotron X-ray diffraction (HEXRD) under containerless electrostatic levitation conditions. Complementary low-temperature HEXRD experiments reveal the structural evolution across a wide temperature range, offering a comprehensive understanding of the mechanisms responsible for the enhanced GFA.

Keywords: Ni-Nb alloys; Bulk metallic glass; Thermodynamics and Kinetics; Crystallization Behavior; Structure