Apparatus for preparation of sintered ceramic body of large dimension

A computer readable medium storing processor-executable instructions adapted to cause one or more computing devices to create sintered ceramic bodies having dimensions of about 100 mm to about 625 mm by a method comprising:

• a. disposing at least one ceramic powder having a specific surface area of from 1 to 18 m2/g as measured according to ASTM C 127 4 inside an inner volume of a spark plasma sintering tool, wherein the spark plasma sintering tool comprises a die comprising a sidewall comprising an inner wall and an outer wall, wherein the inner wall has a diameter that defines the inner volume, an upper punch and a lower punch operably coupled with the die, wherein each of the upper punch and the lower punch 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 μm to 100 μm wide between each of the upper punch and the lower punch and the inner wall of the die when at least one of the upper punch and the lower punch moves within the inner volume of the die,
• wherein the spark plasma sintering tool comprises on the inner wall of the die at least one conductive foil which has a minimum thickness of 25 μm and wherein the distance of the gap is measured from the inwardly facing surface of the conductive foil closest to the upper and lower punches to the outer wall of each of the upper and lower punches;
• b. moving at least one of the upper punch and the lower punch to apply pressure to the ceramic powder while heating the ceramic powder to a sintering temperature and sintering the ceramic powder to form the sintered ceramic body;
• and
• c. lowering the temperature of the sintered ceramic body.