Description:
Amorphous steels exhibit superb mechanical properties for a variety of high-performance applications, but they are significantly more brittle than conventional high-carbon steels. The fracture toughness of this group of materials must be improved prior to utilizing them as structural components.
Scientists at the University of Virginia have developed an amorphous steel composite that exhibits enhanced fracture strengths and elastic moduli, as well as fracture features that indicate improved ductility. They have also developed practical methodologies to successfully produce these composites. In this approach, amorphous steels are reinforced with hard, stiff particulates in a process that circumvents partial devitrification of the glass matrix and the need to heat the components to very high temperatures to produce a homogeneous mixture. Devitrification usually results in the embrittlement of the glass matrix. Overheating can result in significant alteration of the glass forming composition, which can lead to a reduced glass forming ability. Thus, the present synthesis methods retain much of the high glass forming ability, enabling the production of amorphous steel composite rods with a robust glass matrix.
The present invention exhibits non-ferromagnetic properties at ambient temperature as well as enhanced mechanical properties. Compared to other amorphous steels, these alloys exhibit magnetic transition temperatures below the ambient, enhanced strengths and elastic moduli, improved ductility and good corrosion resistance. These novel materials are the first reported castable amorphous steel composite for non-ferromagnetic structural applications. Furthermore, since the synthesis-processing methods use industrial grade raw materials and do not involve any special materials handling procedures, they are directly adaptable to low-cost industrial processing.
