Patent ID: 6230539
Filing Date: 2001-05-15
Classification: B21J,B21K,F42B

Abstract:
An ultra precision forming method employing controlled plastic deformation of metals at elevated temperatures to achieve production of components to the precision required for millimeter wavelength and sub-millimeter wavelength requirements, the method comprising the steps of:(i.) providing a double action press with ability to be computer controlled for both down and up stroke on ram, said ram having a down controllable speed 0 to 0.250 inches/sec and an up controllable speed of 0.250 inches/sec, said double action press adapted for receiving a solid material billet/blank with the volume of the blank tailored to volume of finished part thereby minimizing material wastage, and said double action press adapted for receiving a die member comprised of two halves wherein said solid material billet/blank is enclosed in said die member halves;(ii.) placing said die members in said double action press, said die members being ultrasonically polished on internal surfaces and sidewalls which are subsequently coated with a dry film lubricant a tungsten disulfide to prevent galling when finished part is ejected from said die members;(iii.) inserting said solid material billet/blank within said die member halves in the open position of said double action press, said solid material billet/blank selected from aluminum alloys and aluminum composites;(iv.) closing said double action press to preheat position where said solid material billet/blank is enclosed within said die member halves and holding at preheat displacement for a predetermined time;(v.) isothermally heating said die member halves and said solid material billet/blank in the range of 80 percent to 95 percent of the melting point of said solid material billet/blank while holding in said preheat displacement position with no force being applied;(vi.) transitioning from preheat displacement to force rate control and holding at a peak force for a predetermined time and at a predetermined temperature hold time to achieve forming of said material billet/blank;(vii.) forming said billet/blank by closely controlled high temperature compression force profile tailored over time to manage internal stresses during forming and minimizing residual stresses in finished part; and,(viii.) commanding said double action press to return to loading or said open position to recover said finished part.