COMPARISON TESTINGS BETWEEN 2 HIGH-TEMPERATURE STRAIN-MEASUREMENT SYSTEMS

An experimental evaluation was conducted at NASA Lewis Research Center to compare and contrast the performance of a newly developed resistan ce strain gage, the PdCr temperature-compensated wire strain gage, to that of a conventional high-temperature extensometry, The evaluation o f the two strain measurement systems was conducted through the applica tion of various thermal and mechanical loading spectra using a high-te mperature thermomechanical uniaxial testing system equipped with quart z lamp heating. The purpose of the testing was not only to compare and contrast the two strain sensors but also to investigate the applicabi lity of the PdCr strain gage to the testing environment typically empl oyed when characterizing the high-temperature mechanical behavior of s tructural materials, Strain measurement capabilities to 800 degrees C were investigated with a nickel base superalloy IN100 substrate materi al, and application to titanium matrix composite (TMC) materials was e xamined with the SCS-6/Ti-15-3 [0](8) system, PdCr strain gages instal led by three attachment techniques-namely, flame spraying, spot weldin g and rapid infrared joining-were investigated.