A method of forming a ceramic body including forming a mixture made of at least a first powder material (PM1) including carbon having a first average particle size (PS1), a second powder material (PM2) including carbon and different than the first powder material, the second powder material having a second average particle size (PS2) less than the first average particle size (PS1), and an aluminum content (AC2) greater than the aluminum content (AC1) of the first powder material, and further including forming a green body from the mixture, and sintering the green body and forming a ceramic body having a first type of grain having an average grain size of not greater than about 8 times the first average particle size (PS1).