Injection molding of metallic glass by rapid capacitor discharge

摘要

An apparatus and method of uniformly heating, softening, and thermoplastically forming magnetic 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 injection molding apparatus comprising:
a source of electrical energy comprising a capacitor; at least two electrodes configured to interconnect said source of electrical energy to a sample of metallic glass formed from a metallic glass forming alloy when placed in contact with said electrodes, said sample having a substantially uniform cross-section; at least one plunger being movable in relation to said sample; an injection force generator disposed in relation to the at least one movable plunger such that an injection force may be applied to the sample though said movable plunger; an injection molding die formed in two cooperative halves, such that when the cooperative halves are brought together they combine to comprise:
an electrically insulated feedstock channel configured to accept the sample and place said sample in electrical connection with said at least two electrodes such that substantially intimate connections are formed between said electrodes and said sample, and in mechanical connection with said at least one plunger such that said injection force is transmitted to said sample,a thermally conductive mold configured to cool and form said sample into a metallic glass article, andat least one thermally conductive runner channel forming a fluid interconnection between said feedstock channel and said mold;wherein said source of electrical energy is capable of producing and discharging a quantum of electrical energy sufficient to substantially uniformly heat the sample to a processing temperature between the glass transition temperature of the metallic glass and the equilibrium melting point of the metallic glass forming alloy;wherein said injection force generator is capable of applying an injection force through said at least one movable plunger sufficient to urge said heated sample through said runner channel into said mold to form a net shape article therein.