A spark plasma sintering tool. The tool comprises a die including an inner wall having a diameter that defines an inner volume configured to receive a ceramic powder, and an upper punch and a lower punch operably coupled with the die, wherein each of the upper and lower punches have an outer wall defining a diameter that is less than the diameter of the inner wall of the die thereby creating a gap from 10 m to 100 m wide between each of the punches and the inner wall of the die when at least one of the punches moves within the inner volume of the die. Also disclosed is a method of using the tool to create a large sintered ceramic body and a computer readable medium storing processor-executable instructions adapted to cause one or more computing devices to operate the tool.

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.

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.