Multi-stream Casting of Wire Directly from Melt

Wire is a versatile product that offer the highest strength in any material and has therefore been a product form that is highly valued in engineering alloys. The idea of direct casting wire directly from metallic alloy melt has been around for long but for many reasons has not progressed to large scale commercialization. The main problem had been the difficulty of maintaining a stable melt stream while melt jet can be quenched and continuously solidified into unbroken wire product. Here, we consider the factors responsible for stabilizing a liquid metallic melt jet and the optimization of these. Experimentation with Fe-Si-B-Cr melts for single and multi-strand is reported. It is demonstrated that high strength metallic glass wires were castable using up to five strands. The role of oxide forming elements in stabilizing and widening the range of process parameters is emphasized. X-ray photon electron spectroscopy (XPS) of direct cast wires showed that stable Cr/Si oxide were formed and the evaluation of experimental cast data suggest that a minimum concentration of oxide former is required to maintain continuity in wire products. Other significant process parameters to be optimized for continuous wire formation in multi-streaming wire casting were, nozzle spacing, nozzle-water clearance, and the cast temperature. The multi-streaming of the wire casting process was achieved using laser drilled nozzles and thus provided a credible path for increasing the throughput in a wire casting process.