out utilizing a strain rate in the range of about 2 u00d7 10 5 to about 10 3 seconds 1 the constant load method is readily carried out with the same apparatus as disclosed for the constant displacement method by moving the piston by a constant load force utilizing a constant load weight positioned on the piston to move the piston the load p is readily calculated from the equation p 2 u03c3a where a is the initial cross sectional area of the workpiece i e the cross sectional area of the sintered preform and the factor of 2 is used to account for the increase in area during the forging process as the preform gradually assumes the shape of the final part and u03c3 is the stress that corresponds to initial strain rates as set forth above for the constant displacement rate method the constant stress method is readily carried out with apparatus as described for the constant displacement method modified to include variable load applying means where varying of the load is controlled responsive to a microprocessor programmed to vary load as workpiece cross sectional area increases to provide a constant stress in accordance with the equation where p is the load u03c3 is stress and a is the cross sectional area of the workpiece flow stresses should be less than 100 megapascals and preferably range from about 5 to about 50 megapascals in each of the four methods described above for step d the forging i e pressing is stopped when appropriate dimensions of the part being formed have been achieved as estimated from the total displacement applied to the piston utilized.