Year Inducted: 1991
Southern Research Institute (SRI) is a contract research company in Birmingham, Alabama. Testing those materials directly involved in high temperature applications testing them with very precise, reliable results has become the norm at SRI, thanks to the development of the institute’s high temperature materials evaluation facility. Credit for this important advance belongs to SRI’s Mechanical and Materials Engineering Department.
Materials evaluated at SRI are those used in applications such as rocket nozzles, nose cones, and nozzle exit cones, and in heat shields, jet engines, and airfoils, where materials are exposed to high temperature gases, developing high thermal stresses. The tensile test facility was created to determine how materials will serve under the extreme thermal stresses resulting from aerodynamic loads and thermal gradients.
To measure strain at high temperature, an optical strain analyzer was developed and incorporated in the test facility. It was the first instrument in the country capable of recording high temperature strain on brittle materials. The facility was the recipient of a 1964 ASTM TEMPLIN Award for testing. A second component of the unique SRI facility comprises apparatus for determining thermal properties of ceramic and graphitic materials at high temperature. SRI engineers developed furnaces with specially designed instrumentation to record thermal conductivity, thermal expansion, and the specific heat of materials of interest. This project received the Industrial Research/ Development Magazine Award, which designated it one of the one hundred most significant projects of 1963.
Special ring test facilities were added later, allowing for the application of internal and external loads to circular sections of rocket nozzles and exit cones and permitting monitoring of the subsequent dimensional changes of the ring sections. In recent years, methods for making these same measurements at rapid heating rates (to simulate hostile environments) have been developed, as have methods to ascertain the mechanical properties of thin-walled tubes used in space structures. In addition, non-destructive characterization studies help in determining the uniformity and soundness of materials.
SRI has furthermore presented new methods and instrumentation for quantifying the reoxidation products generated when steel is cast in an air environment; and new technologies to determine heat removal rates for liquid quenchants and to measure some parameters of lost-form casting.
The primary contribution of the SRI high temperature materials evaluation facility has been to provide much more precise information used in the design of missile, space shuttle, and aircraft components. This refined information increases the reliability of the components, and thus the reliability and safety of our entire space and defense programs are enhanced by work performed in this facility.
