Accession Number : AD0852026

Title :   Magnetoabsorption Techniques For Measuring Material Properties. Part II: Measurement of Residual and Applied Stress.

Descriptive Note : Final rept. Jan 66-Oct 67,

Corporate Author : SOUTHWEST RESEARCH INST SAN ANTONIO TX

Personal Author(s) : Rollwitz, William L.

Report Date : MAR 1969

Pagination or Media Count : 169

Abstract : The thermal degradation of several polyimidazopyrrolone (pyrrone) films was studied in air and in vacuum over the range of 100-1000 deg C. by thermogravimetric analysis (TGA), with the use of both isothermal heating and programmed heating rates of 2,3,5, and 7.5 deg C./min. At pressures of 10-6 torr or less, maximum weight losses average 30% at 800 deg C. Rates of volatilization and activation energies were derived to provide comparison between these ladder-type polymers. Mass spectrometric analysis of the pyrolysis gases evolved under vacuum conditions showed that CO, CO2, and H20 were the primary volatile products and that they were formed throughout the period of weight loss. The ability of these materials to absorb readily 5-7 wt.-% of water under ambient conditions and the effect of this property upon weight loss measurements are shown. (Author, modified-PL).

Descriptors :   (*FERROMAGNETIC MATERIALS, NONDESTRUCTIVE TESTING), MAGNETIC PROPERTIES, METAL COATINGS, MEASUREMENT, TURBINE BLADES, RODS, MATERIAL FORMING, MATERIALS, REMOVAL, AXIAL FLOW COMPRESSOR BLADES, JET ENGINES, LANDING GEAR, STRESSES.

Subject Categories : Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE