Determination of the Mechanical Properties of Aircraft-Structural Materials at Very High Temperatures after Rapid Heating

Structural components in high-speed aircraft and in missiles must function for short periods of time at high temperatures and at high stresses, and frequently the heating and loading occur simultaneously. The requirement for reliability without overdesign demands accurate test data obtained under conditions approximating the expected operating conditions. In an effort to fulfill a portion of this need, this program was divided into four independent areas of work as follows: (1) The tensile properties of unalloyed beryllium were determined at test temperatures from ambient through 1500 deg F. (2) The short-time, elevated-temperature tensile properties were determined for ten combinations of base materials and coating materials (Cr-Ni electroplate on copper sheet, Rokide A on copper sheet, Rokide Z on copper sheet, Rokide ZS on copper sheet, Cr electroplate on A-nickel sheet, Ni-Cr electroplate on molybdenum sheet, Rokide Z on molded graphite, Rokide ZS on molded graphite, Crystalon C on molded graphite and SiC-SiN on molded graphite). (3) The effects of linear thermal gradients up to 1500 deg F/in on the tensile properties of a typical refractory alloy were investigated. (4) The effects of simultaneous heating and loading on the tensile properties of a typical structural alloy were investigated. This report covers the first three of these four areas of work; a supplementary report will be issued shortly containing all of the results of the investigations involving simultaneously transient temperature and load.