Volume 28, Issue 3 (May 2000)
Dynamic Shear Modulus and Damping in Iron-Copper and Steel-Based Metal Matrix Composites
Measurements were made of the density, dynamic shear modulus, damping, strain amplitude, and resistivity in iron-copper and steel-based metal matrix composites. The density was determined using the Archimedes method and was found to be in the range of 7463 to 8257 kg/m3. The shear modulus, damping, and strain amplitude were determined using the piezoelectric ultrasonic composite oscillator technique (PUCOT). The shear modulus was in the range of 73 to 81 GPa. Electrical resistivity measurements were performed to assess the change in the conductivity of the composites by adding copper. Metallographic studies and microhardness testing were performed to assess the distribution and hardness of the fibers in the composites. The variation of shear modulus and electrical conductivity with respect to the percentage of copper in some of the composites followed the rule of mixtures. The damping in the specimens was near 3 × 10-3 and independent of strain amplitude.