A method of forming a consolidated component having a complex shape includes providing a first component having a first shape similar to the complex shape. The method further includes placing the first component in a chamber and surrounding the first component with a medium. The method further includes applying pressure and at least one of heat or electricity into the chamber to process the first component to form a consolidated component having the complex shape.

A method of making a sintered ceramic body comprising the steps of disposing a ceramic powder (5) inside an inner volume of a spark plasma sintering tool (1), wherein the tool comprises: a die (2) comprising a sidewall comprising inner and outer walls, wherein the inner wall has a diameter defining the inner volume; upper and lower punches (4,4) operably coupled with the die, wherein each of the punches have an outer wall defining a diameter less than the diameter of the die inner wall, thereby creating a gap (3) between the punches and the inner wall when at least one of the punches are moved within the inner volume, and the gap is from 10 m to 70 m wide; creating vacuum conditions inside the inner volume; moving at least one of the punches to apply pressure to the ceramic powder while heating, and sintering; and lowering the temperature of the sintered body.

Various embodiments of the disclosure provide methods using spark plasma sintering (SPS) at moderate temperatures and moderate pressures to fabricate high-density graphite material. The moderate temperatures may be temperatures not exceeding about 1200 C. The moderate pressures may be pressures not exceeding about 300 MPa. The high density exhibited by the resulting, sintered, high-density graphite material may be greater than about 1.75 g/cm.sup.3 (e.g., greater than about 2.0 g/cm.sup.3).

A method of making a sintered ceramic body comprising the steps of disposing a ceramic powder inside an inner volume of a spark plasma sintering tool, wherein the tool comprises: a die comprising a sidewall comprising inner and outer walls, wherein the inner wall has a diameter defining the inner volume; upper and lower punches operably coupled with the die, wherein each of the punches have an outer wall defining a diameter less than the diameter of the die inner wall, thereby creating a gap between the punches and the inner wall when at least one of the punches are moved within the inner volume, and the gap is from 10 m to 70 m wide; creating vacuum conditions inside the inner volume; moving at least one of the punches to apply pressure to the ceramic powder while heating, and sintering; and lowering the temperature of the sintered body.

The invention relates in general to sintering under pressure and with electrical current, often termed spark plasma sintering (SPS). Particular aspects of the invention are directed to a sintering device, a sintering process, a ceramic body product, an assembly comprising the ceramic body and the use of a graphite layer in a sintering process. The invention relates to a device having a sintering chamber, the sintering chamber being bordered by the following device parts: i. a first punch surface of a first punch; ii. a second punch surface of a second punch; and iii. an interior surface of a die; wherein: the punches are adapted and arranged to apply a pressure of at least 1 MPa along a compression axis to a target in the sintering chamber; the first punch and the second punch are connected to an electrical power source.

A process for the preparation of a ceramic body, comprising the steps: a. providing a plurality of particles; b. providing a device that comprises a sintering chamber bordered by a die; c. introducing the particles into the sintering chamber; d. applying a pressure P in the range from 1 MPa to 80 MPa to the plurality of particles in the sintering chamber to obtain the ceramic body, wherein a temperature in the sintering chamber, during preparation of the ceramic body, is controlled so that the temperature at a centre of the sintering chamber is lower than the temperature at an interior surface of the die.

A method of forming an article includes placing a feed material and a filler material in one or more cavities of a die assembly of a sintering apparatus and applying heat and pressure across the feed material and the filler material to form one or more sintered articles comprising the feed material. A die assembly of the sintering apparatus includes an upper punch, a lower punch defining one or more first through holes, the one or more first through holes defining one or more first cavities configured to receive a feed material, and a die defining a second through hole configured to at least partially receive the upper punch and the lower punch, the second through hole and at least one of the upper punch and the lower punch defining a second cavity configured to receive a filler material.