Accession Number : ADA313525

Title :   DURIP/ARO Program on Time-Resolved Pressure-Measurement Instrumentation for High-Strain Rate Materials Synthesis.

Descriptive Note : Final rept. 7 Jun 95-6 Jun 96,

Corporate Author : GEORGIA INST OF TECH ATLANTA

Personal Author(s) : Thadhani, N. N. ; Russell, R. ; Vandersall, K.

PDF Url : ADA313525

Report Date : 31 JUL 1996

Pagination or Media Count : 9

Abstract : In this program, advanced diagnostic instrumentation was developed for time-resolved pressure measurements for experimentation involving materials synthesis by shock-compression of powders and their mixtures. The instrumentation has been developed with the objective of (a) allowing to determine the shocked state of material in real time with nanosecond resolution, to quantitatively correlate the loading histories with post-shock characteristics of materials produced using recovery experiments; and (b) monitoring the shock-initiated transformation or chemical reaction processes in real time by observing the response of in-situ probes to obtain a detailed understanding of the mechanisms and kinetics of processes occurring during the shock-compression state. The instrumentation developed is based on tune-resolved stress-wave measurements using the piezoelectric polyvinylidene-flouride (PVDF) gages, and includes: two Tektronix 784A digital oscilloscopes (1 GHz bandwidth, 1 GS/s rate, and 4 channels) and the associated hardware including high-frequency low-loss coaxial transmission cables, HP pulse and delay generator, HP electronic counters, and an independent circuitry several sets of gages. The instrumentation will be extensively useful for enhancing the quality of on-going research supported by ARO under Grant No. DAAH04-94-G-0192, entitled 'An Investigation of the Mechanisms, Kinetics, and Energetics of Shock-induced Chemical Reactions in the Ti-Al/Si/B System,' and the AASERT program on 'Combustion Synthesis of High-density Powder Mixture Compacts under Conditions of Dynamic Stress and Electric Field.'

Descriptors :   *PRESSURE MEASUREMENT, *STRESS WAVES, COMPRESSION, PLASTIC DEFORMATION, STRESS STRAIN RELATIONS, LOAD DISTRIBUTION, MICROSTRUCTURE, ALUMINUM ALLOYS, REAL TIME, REACTION KINETICS, PHASE TRANSFORMATIONS, SHOCK WAVES, PRESSURE GAGES, STRAIN RATE, IMPACT SHOCK, STRUCTURAL RESPONSE, POWDER METALLURGY, DYNAMIC PRESSURE, TITANIUM ALLOYS, PIEZOELECTRIC GAGES.

Subject Categories : Mechanics
      Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE