Experimental and Mathematical Modelling of Bulk Amorphous Structure Formation in Multi-Component Alloys via Twin-Roll Rapid Solidification

Abstract This study investigates the formation processes of amorphous layers via twin-roll rapid solidification, focusing on the critical factors that govern the conversion of the melt into a solid amorphous phase. The core objective was to identify and optimise the critical processing parameters that govern the melt’s conversion into a solid amorphous phase. The Ni 62.4 Nb 37.6 alloy was selected as the model system, notably possessing a relatively low critical cooling rate in the range of R c from 10 2 to 10 3 K/s. Through experimental trials, this process successfully yielded a bulk amorphous layer, which was subsequently confirmed by comprehensive metallophysical characterisation. Key variables such as the gap between the rollers, roller speed, and cooling air temperature were systematically investigated. The experimental analysis determined the degree of amorphisation Ψ that could be achieved, with optimal conditions yielding values up to 6. Furthermore, a detailed mathematical model was developed and employed to precisely determine the thermal fields and optimise the essential technological parameters by correlating them with the local cooling kinetics. The resulting amorphous microstructures obtained by this method are high-performance materials, demonstrating a remarkable Vickers hardness of 740 HV, confirming the viability of this technique for developing next-generation structural materials.