Sheet forming of metallic glass by rapid capacitor discharge

摘要

An apparatus and method of uniformly heating, rheologically softening, and thermoplastically forming metallic glasses rapidly into a net shape using a rapid capacitor discharge forming (RCDF) tool are provided. The RCDF method utilizes the discharge of electrical energy stored in a capacitor to uniformly and rapidly heat a sample or charge of metallic glass alloy to a predetermined “process temperature” between the glass transition temperature of the amorphous material and the equilibrium melting point of the alloy in a time scale of several milliseconds or less. Once the sample is uniformly heated such that the entire sample block has a sufficiently low process viscosity it may be shaped into high quality amorphous bulk articles via any number of techniques including, for example, injection molding, dynamic forging, stamp forging, sheet forming, and blow molding in a time frame of less than 1 second.

主权项

1. A rapid capacitor discharge apparatus for rapidly heating an amorphous metal and forming the amorphous metal into a sheet comprising:
a sample of an amorphous metal, said sample having a substantially uniform cross-section; a source of electrical energy; at least two electrodes interconnecting said source of electrical energy to said sample of amorphous metal, said electrodes being attached to said sample; a sheet forming tool comprising an enclosure having at least one opening and a plunger, and at least one pair of rollers arranged parallel to each other and disposed external to the enclosure and adjacent to the opening; wherein said source of electrical energy is capable of discharging a quantum of electrical energy sufficient to heat the entirety of said sample to a processing temperature between the glass transition temperature of the amorphous metal and the equilibrium melting point of the alloy, and wherein said sheet forming tool is capable of applying a compressive force sufficient to eject said heated sample through said opening and between the at least one pair of rollers, and the roller pair being configured to apply a deformational force to form a sheet.