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US 6,383,446 B1Granted
Method and system for automatic electrical sintering
AssigneeSumitomo Coal Mining Co., Ltd.
InventorMasao Tokita
Life of this patent
Estimating the term…
Abstract
The present invention is a method of automatically loading powder material into a sintering mold and subsequently effecting electrical sintering to the powder material in the sintering mold.
Claims20
A method of automatically loading powder material into a sintering mold and subsequently effecting electrical sintering to said powder material in said sintering mold, said method comprising the steps of:
- fitting a lower press core into a bore formed in said sintering mold, while allowing displacement of said lower press core in said bore;
- filling different powder materials, which differ from one another in at least one of properties including component(s) of powder material, percentages of components, particle size and particle shape, into said bore to form respective powder layers of said different powder materials in said bore, while displacing said lower press core downward in said bore sequentially and in a stepwise manner, such that the position of a top surface of said lower press core from a top surface of said sintering mold is adjusted depending on the thickness of said respective layers of said different powder materials being filled into said bore;
- preliminarily pressing at a desired pressure said powder layers of said different powder materials;
- displacing said pressed powder layers together with said lower press core relative to said sintering mold so as to position said powder layers to a desired position in said sintering mold;
- fitting an upper press core into said bore of said sintering mold and onto said powder layers;
- pre-heating to a desired temperature said sintering mold with said powder layers formed therein and with said upper press core fitted therein;
- and
- effecting electrical sintering to said powder layers by:
- operating upper and lower conductive members so as to press at a desired pressure said upper press core and said lower press core fitted in said sintering mold having been pre-heated;
- and simultaneously applying sintering current to said powder layers through said upper and lower conductive members.
7 more elements
An automatic electrical sintering system for automatically loading powder material into a sintering mold and subsequently effecting electrical sintering to said powder material in said sintering mold, comprising:
- an automatic powder material loading apparatus for automatically loading a desired amount of powder material into said sintering mold and pressing said powder material;
- a pre-heating unit disposed along a transportation path of said sintering mold and downstream of said automatic powder material loading apparatus, for pre-heating said sintering mold;
- a sintering unit including conductive members for contacting a pair of press cores fitted in said sintering mold pre-heated by said pre-heating unit, with said powder material being held between said press cores, said sintering unit further including means for applying sintering current to said powder material through said plunger electrodes to effect electrical sintering to said powder material in said sintering mold;
- and
- a conveyor for conveying through said sintering unit said sintering mold sent from said automatic powder material loading apparatus;
- wherein said sintering unit includes a substantially gas-tight chamber.
3 more elements
An automatic electrical sintering system for automatically loading powder material into a sintering mold and subsequently effecting electrical sintering to said powder material in said sintering mold, comprising:
- an automatic powder material loading apparatus for automatically loading a desired amount of powder material into said sintering mold and pressing said powder material;
- a sintering unit disposed along a transportation path of said sintering mold and downstream of said automatic powder material loading apparatus and including conductive members capable of contact with a pair of press cores fitted in said sintering mold, with said powder material being held between said press cores, said sintering unit applying sintering current to said powder compact through said conductive members to effect electrical sintering to said powder material in said sintering mold;
- a conveyor for conveying through said sintering unit said sintering mold sent from said automatic powder material loading apparatus;
- a sintering power supply for providing sintering current;
- and
- a pre-heating power supply for providing pre-heating current;
- wherein said conductive members are capable of selective electrical connection to said sintering power supply and said pre-heating power supply, so that said pre-heating current and said sintering current is selectively applicable to said sintering mold through said conductive members;
- and
- wherein said sintering unit includes a substantially gas-tight chamber having an atmosphere therein which is controllable to be selectively one of atmospheres including a pre-heating atmosphere and a sintering atmosphere.
6 more elements
Dependencies are inferred from the claim text.