Process and apparatus for the preparation of particulate or solid parts
AssigneesDennis Tool Company, The Penn State Research Foundation
InventorsRustum Roy, Dinesh Agrawal, Jiping Cheng, Mahlon Dennis, Paul D. Gigil
Life of this patent
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Abstract
The present disclosure is directed to a method of converting green particles to form finished particles. The apparatus used for sintering incorporates an elongate hollow tube, an insulative sleeve there about to define an elevated temperature zone, and a microwave generator coupled through a wave guide into a microwave cavity incorporated the tube. The particles are moved through the tube at a controlled rate to assure adequate exposure to the microwave radiation. Another form sintered a solid part in a cavity or mold.
Claims32
A method of preparing sintered particles comprising the steps of:
- (a) putting green particles into an elongate hollow tube having an axial passage therethrough to enable flow of the particles through the tube in the axial passage along the tube from an inlet to an outlet of the tube;
- (b) forming microwave energy radiation directed into the tube to cause heating of the particles in the tube;
- and
- (c) moving the particles along the tube relative to the microwave radiation so that the radiation acts on the particles in a controlled fashion to thereby heat and sinter the particles.
An apparatus for sintering loose particles comprising:
- (a) an elongate hollow tube formed of a material which is transparent to microwave radiation;
- (b) an inlet at one end of the tube to enable green particles to be placed in the tube, and further including a passage therethrough communicating to a tube outlet;
- (c) an insulative sleeve surrounding said tube wherein the sleeve defines a heating zone;
- (d) a microwave generator;
- (e) a wave guide connected from the generator to form a radiation cavity surrounding and coupled with the tube so that radiation from the microwave generator is coupled through the wave guide and into the cavity which includes the heating zone of the tube;
- and
- (f) means for providing relative movement between the microwave radiation and the particles in the tube so that the particles have a specified dwell time in the heating zone and are held in the heating zone for an interval sufficient to be converted from green particles into the sintered particles.
An apparatus for sintering a molded piece, comprising:
- (a) an elongate tube having a cavity for receiving green unsintered particles therein;
- (b) an insulative sleeve surrounding said tube wherein the sleeve defines a heating zone;
- (c) a microwave generator;
- (d) a wave guide connected from the generator to form a radiation cavity surrounding and coupled with the tube so that radiation from the microwave generator is coupled through the wave guide and into the cavity which includes the heating zone of the tube;
- and
- (e) means for providing relative movement between the microwave radiation and the particles in the tube so that the particles have a specified dwell time in the heating zone and are held in the heating zone for an interval sufficient to be converted from green particles into the sintered particles.
A method of preparing a shaped hard body comprising the steps of:
- (a) defining green particles comprising a first green particle material and a second green particle material into a desired finished hard body shape, wherein
- (i) said first green particle material comprises a first binder homogeneously mixed therein,
- (ii) said second green particle material comprises a second binder homogeneously mixed therein, and
- (iii) said first and second binders comprise a common element in differing concentrations;
- (b) moving the shaped green particles through microwave energy radiation to cause heating wherein the radiation acts on the particles in a controlled fashion to sinter the particles into a unitary body.
Dependencies are inferred from the claim text.