Ultra precision net forming process employing controlled plastic deformation of metals at elevated temperatures

Abstract

An ultra precision net shape forming process is disclosed which can satisfy the requirements of MMW and sub-MMW components and sabots for small caliber armor piercing ammunition. The process is well suited to both moderate and high volume applications, and offers the potential for dramatically reducing piece part fabrication costs. The process involves closely controlled high temperature compression forming of metals with cycle times of the order of one minute or less, precise replication of all die features, and very low residual stresses. The ultra precision net shape forming cycle starts following insertion of the billet/blank into an open die. In the preheat phase the press is closed to preheat position where the billet/blank is enclosed in both halves of the die but no force is applied. Following preheat the part is formed employing displacement and force control to insure a fully formed part. After holding for a preset time at the peak force, the press is then commanded back to the loading position. The process has many of the attributes of conventional compression molding of plastics and is well suited to high volume, automated production of complex precision parts.