Apparatus and method for casting amorphous metal alloys in an adjustable low density atmosphere

An apparatus and method for casting metal strip includes a moving chill body that has a quench surface. A nozzle mechanism deposits a stream of molten metal on a quenching region of the quench surface to form the strip. The nozzle mechanism has an exit portion with a nozzle orifice. A depletion mechanism includes a plurality of independently controllable gas nozzles to supply a reducing gas to multiple zones of a depletion region located adjacent to and upstream from the quenching region. The gas flow profile can be controlled in each zone independently of controlling the gas flow in other zones. The reducing gas reacts exothermically to lower the density to provide a low density reducing atmosphere within the depletion and substantially prevent formation of gas pockets in the strip.