Evaluation of Thermal Stress Resistance in Potential Radome Materials

摘要

The relative thermal stress resistance of five potential radome materials was experimentally determined for heating conditions which simulated radome environments. The effects of wall thickness and notches were also studied. Pyroceram 9608 was found to be the most thermal stress resistant of the five materials studied; the others, in decreasing order of merit, were Pyrex 7740, AD-99 alumina, MgO (99+% dense), Alundum RA-3360. The effects of notches and of the wall thicknesses studied (1/4 inch and 3/8 inch) were small compared with the differences between materials. However, theoretical considerations, together with extrapolation of experimental results, indicated that considerable improvement in thermal stress resistance might be obtained from much smaller wall thicknesses (0.10 inch or less). A fair correlation was obtained between the experimental results and four pertinent parameters. Pyroceram 9608 ranked as the most thermal stress resistant material in the ratings obtained from all four parameters. (Author)