Berlin 2024 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 36: Liquid and Amorphous Materials I

MM 36.4: Vortrag

Mittwoch, 20. März 2024, 12:30–12:45, C 243

Ni-Nb-P-based bulk glass-forming alloys: Superior material properties combined in one alloy family — •Lucas Ruschel and Ralf Busch — Chair of Metallic Materials, Saarland University, Saarbrücken 66123, 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. However, the main drawback is the limited glass-forming ability (GFA), narrowing the field of application to solely small components. 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 4 mm across a broad bulk glass forming region, culminating in a record value of 5 mm, which surpasses the binary Ni₆₂Nb₃₈ alloy by 150 %. Moreover, the primary precipitating phase, playing a crucial role for glass formation, is determined by container-less electrostatic levitation in-situ high-energy X-ray diffraction experiments. The mechanical properties of the new alloys are characterized in uniaxial compression tests and Vickers hardness measurements, showing a high engineering yield strength of 3 GPa, an extended plastic regime up to 10 % strain to failure and an increase of the hardness to a maximum value of 1000 HV5. Additionally, calorimetric measurements reveal an extended supercooled liquid region up to 69 K, permitting thermoplastic forming of amorphous feedstock material.

Keywords: Glass-forming ability; Ni-Nb alloys; High-strength material; Bulk metallic glass; Electrostatic levitation