DEVELOPMENT OF TECHNIQUES FOR PRODUCING BERYLLIUM STRUCTURAL SHAPES. Fourth Interim Technical Report, May 19, 1961-November 13, 1961. Final Phase III Report

The Phase III effort has extended the processing information obtained in Phase ll to allow the attainment of the desired structural shapes through several alternative processes. The round and square solid shapes have been proven readily producible through simple roll reduction of previously extruded shapes. Angles, channels, and zees can be formed through the bending of sheet metal of the desired thickness to the desired geometry. This program has demonstrated that for forming at 1350 to l400 deg F, 0.060-inch thick sheet required a 3T to 4T internal forming radius if roll forming was used whereas a 7T radius was necessary for mechanical press-brake forming. For 0.188-inch thick sheet a radius of 3T to 4T was required for roll forming, and mechanical press-brake forming required a 4i//T radius for satisfactory bends in this temperature range. A composite billet process was developed for the production of tee-shaped sections that were not producible by the methods used for the other shapes. In comparing the advantages of this process with the other production paths studied, it was decided that all Phase IV shapes would be produced by this method. Considerable potential exists in this method for the production of increasingly complex shapes tomore » higher strength levels than those originally specified for the program. Introductory experiments have demonstrated the ability to achieve over 100,000 psi ultimate tensile strength and 70,000 psi tensile yield strength wlth 5% elongation in using this approach. (auth)« less