A variety of MMC's (Al matrix with discontinuous SiC whiskers) and PMC's (graphite/polyimide and carbon-carbon), as well as powder metallurgy (PM) aluminum were investigated with the PUCOT (piezoelectric ultrasonic composite oscillator technique) at frequencies near 80 kHz. Young's modulus and damping were measured as functions of temperature) up to approximately 400 degrees C. The results for the different materials are discussed briefly and recommendations are made for future research in ...
This paper analyzes measurements of the strain amplitude dependence of internal friction for several metal matrix composites (1100 Al, 2124 Al, and 6061 Al reinforced with SiC) to determine the concentration of dislocations that were mobile during low strain (<0.0001) ultrasonic tests. The apparatus used was the PUCOT (Piezoelectric Ultrasonic Composite Oscillator Technique) at room temperature and at 80 or 100 kHz. Two approaches to the analysis are considered: the ...
Measurements of the strain amplitude dependence of internal friction for several metal matrix composites (1100 Al, 2124 Al, and 6061 Al reinforced with SiC) have been analyzed to determine the concentration of dislocations that were mobile during low strain (<10E-4) ultrasonic tests. The apparatus used was the PUCOT (Piezoelectric Ultrasonic Composite Oscillator Technique) at room temperature at 80 or 100 kHz. Two approaches to the analysis are considered: the Granato-Luecke ...
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