California Institute of Technology

Glassimetal Technology Inc.

Apple Inc.

Joseph P Schramm

William L Johnson

Marios D Demetriou

Georg Kaltenboeck

David S Lee

Choong Paul Kim

Douglas C Hofmann

Jong Hyun Na

Scott N Roberts

Chase Crewdson

Xiao Liu

Montague Rittgers

Henry Kozachkov

The disclosure is directed to an apparatus comprising feedback-assisted control of the heating process in rapid discharge heating and forming of metallic glass articles.

Feedback-assisted rapid discharge heating and forming of metallic glasses

A rapid discharge heating and forming apparatus is provided. The apparatus includes a source of electrical energy and at least two electrodes configured to interconnect the source of electrical energy to a metallic glass sample. The apparatus also includes a shaping tool disposed in forming relation to the metallic glass sample. The source of electrical energy and the at least two electrodes are configured to deliver a quantum of electrical energy to the metallic glass sample to heat the metallic glass sample. The shaping tool is configured to apply a deformational force to shape the heated sample to an article. The at least two electrodes have a yield strength of at least 200 MPa, a Young's modulus that is at least 25% higher than the metallic glass sample, and an electrical resistivity that is lower than the metallic glass sample by a factor of at least 3.

Durable electrodes for rapid discharge heating and forming of metallic glasses

Methods and apparatus for forming high aspect ratio metallic glass objects, including metallic glass sheets and tubes, by a melt deposition process are provided. In some methods and apparatus a molten alloy is deposited inside a channel formed by two substrates moving relative to each other, and shaped and quenched by conduction to the substrates in a manner that enables the molten alloy to vitrify without undergoing substantial shear flow.

Production of metallic glass objects by melt deposition

The present disclosure is directed to the use of cellulosic materials, such as wood, paper, etc., or synthetic polymeric materials, such as a thermoplastic, rubber, etc., or a composite containing one or more of these materials as feedstock barrels for the process of injection molding of metallic glasses by rapid capacitor discharge forming (RCDF) techniques.

Cellulosic and synthetic polymeric feedstock barrel for use in rapid discharge forming of metallic glasses

The present disclosure is directed to feedstock barrels comprising thermally and electrically insulating films configured to be adjacent to a feedstock sample when it is loaded in the barrel for the process of shaping metallic glasses by rapid capacitor discharge forming (RCDF) techniques.

Feedstock barrels coated with insulating films for rapid discharge forming of metallic glasses

The disclosure is directed to methods of forming metallic glass multilayers by depositing a liquid layer of a metallic glass forming alloy over a metallic glass layer, and to multilayered metallic glass articles produced using such methods.

Methods of forming metallic glass multilayers

The present disclosure is directed to a method of physically separating and electrically isolating the chamber where the ohmic heating of the feedstock occurs by delivering current through the electrodes (heating barrel), from the chamber where the feedstock deformation and flow through the runner takes place by the motion of the plungers (forming barrel). The method also includes transferring the feedstock from the heating barrel to the forming barrel between the heating and the forming processes at a high enough rate such that negligible cooling and no substantial crystallization of the feedstock occurs during the transfer.

Rapid discharge heating and forming of metallic glasses using separate heating and forming feedstock chambers

A mechanically tuned rapid capacitive discharge forming apparatus and methods that utilize compliant and shock absorbing components in electrode assemblies in order to accommodate the stresses and strains of the thermally-expanding feedstock and maintain continuous electrical contact between the electrodes and the feedstock throughout the duration of the electrical discharge.

Mechanically tuned rapid discharge forming of metallic glasses

Methods and apparatus for forming high aspect ratio metallic glass, including metallic glass sheet and tube, by a melt deposition process are provided. In some methods and apparatus a molten alloy is deposited inside a tubular channel formed by two concentrically arranged substrates, and shaped and quenched by conduction to the substrates in a manner that enables the molten alloy to vitrify prior to undergoing substantial shear flow. The deposition method allows the molten alloy to be deposited and formed while being quenched, without undergoing substantial shear flow.

Production of metallic glass by melt deposition

The disclosure is directed to a method of forming high-aspect-ratio metallic glass articles that are substantially free of defects and cosmetic flaws by means of rapid capacitive discharge forming. Metallic glass alloys that are stable against crystallization for at least 100 ms at temperatures where the viscosity is in the range of 10to 10Pa-s are considered as suitable for forming such high-aspect-ratio articles.

Methods for shaping high aspect ratio articles from metallic glass alloys using rapid capacitive discharge and metallic glass feedstock for use in such methods

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, and blow molding in a time frame of Less than 1 second.

Forming of metallic glass by rapid capacitor discharge

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.

Sheet forming of metallic glass by rapid capacitor discharge

An automated rapid capacitive discharge apparatus is provided for sequentially or simultaneously rapidly heating and shaping a plurality of metallic glass feedstock samples. The apparatus includes a sample feeder defining a body for holding a plurality of samples and being capable of sequentially positioning at least one feedstock sample into a discharge position within the processing compartment. In the processing compartment the sample is heated by a discharge of a quantum of electrical energy supplied via electrodes, then shaped into a desired shape by means of a shaping tool, and subsequently moved out of the discharge position as a second feedstock moves into a discharge position.

Automated rapid discharge forming of metallic glasses

Ferromagnetic cores made from amorphous glasses and methods of forming ferromagnetic cores from metallic glasses are provided. The method forms a magnetic core from a section of a series of concentrically nested ferromagnetic tubes formed of an amorphous metallic material having a Curie-point temperature above room temperature and demonstrating soft ferromagnetic properties, thereby simplifying the manufacturing process and improving the electrical and mechanical performance of the core itself.

Ferromagnetic cores of amorphous ferromagnetic metal alloys and electronic devices having the same

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, and blow molding in a time frame of less than 1 second.

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Sierra Madre, CA, United States of America

Joseph P Schramm