DETERMINING THE CONSTITUENT VOLUME FRACTIONS OF METAL MATRIX COMPOSITES BY A MULTIPLE NDT TECHNIQUE
Hyunjo Jeong*, David K. Hsu** and Peter K. Liaw*** *Agency for Defence Development, PO Box 35-4, Taejon Yuseong, Korea **Center for Nondestructive Evaluation, Iowa State University, Ames, IA 50011, USA ***Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996, USA
A multiple nondestructive technique is developed for the evaluation of reinforcement and intermetallics volume fractions in extruded particulate reinforced metal matrix composites. The technique employs theoretical models which account for the constituent phases, together with the measurement of ultrasonic velocity and eddy current conductivity. Both two-phase (matrix- reinforcement) and three-phase (matrix-intermetallics- reinforcement) models are described which relate the anisotropic velocities and conductivities of extruded particulate reinforced composites to their microstructures. In the two-phase model, the reinforcement volume fraction is calculated from the measured velocity in the thickness direction of the composite extrusions. The intermetallics volume fraction is then calculated using the three phase model with the measured conductivity on the extrusion plane. The technique is applied to a wide range of silicon carbide particulate (SiCp) reinforced aluminum matrix composites, and the calculated values are found to be in good agreement with the actual volume fractions.
Publication Source: Trends in NDE Science & Technology; Proceedings of the 14th World Conference on Non-Destructive Testing, New Delhi, 8-13 December 1996.Vol. 2, pages 695 - 698 Publisher:Ashgate Publishing Company
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