a superplastic forming system includes a free standing generally block - shaped ceramic monolithic die base having a bottom surface on which the die rests , and a top surface , opposite to the bottom surface , in which a forming cavity is formed and which is surrounded by a contact surface . the forming cavity has a shape like the desired shape of sheet metal parts to be formed by superplastic forming in the die . a die lid having a horizontal cross sectional shape and size approximately equal to the die base , and having a contact surface corresponding in size and contour to the die base contact surface is placed on the base with the contact surfaces aligning and in contact . the die base is formed of a ceramic material that provides sufficient compressive strength to resist a compressive load exerted by a press to hold the lid on the die against oppositely directed force generated by gas at superplastic forming pressures within the die , and provides sufficient tensile strength , when under pressure of compressive loads exerted by the press to resist internal bursting forces exerted by gas at superplastic forming pressures within the die . a press having upper and lower platens with substantially parallel upper an lower platen faces applies compressive force to the die placed therebetween . the press is preheated and the die is attached with attaching hardware to the press . pressurized gas is delivered to the die cavity from a source through a gas conduit connecting the pressurized gas source to the die .