DEVELOPMENT OF TECHNIQUES FOR PRODUCING BERYLLIUM STRUCTURAL SHAPES. Third Interim Technical Report for Period January 29, 1961 to April 28, 1961. Final Phase II Report

The effects of beryllium oxide level and mill rolling history on the properties of rolled sheet and bar were studied. The studies concluded that the low beryllium oxide product was presently preferred for the development of high strength structural materials because of a better statistical property consistency. In contrast, the higher beryllium oxide material, possessing 5 to 10% higher ultimate tensile strength at room temperature, had greater deviation in both tensile properties and formability than the lower beryllium oxide material. The testing performed to date has indicated that the ultimate tensile and yield strength objectives will be obtainable using the low beryllium oxide material. Although the flat rolled products only approximated the minimum properties to be attained by the end of the program, the testing of roll-reduced bar resulted in tensile properties as high as 103,800 psi ultimate tensile strength, 74,800 psi yield strength, and 6% elongation. Supporting efforts were expended during this phase to evaluate processing variables such as specimen preparation, thermal treatments, surface preparation, and the like to determine the effect on mechanical properties. (auth)