The damping capacity of AZ91 magnesium matrix composites reinforced with the coated carbon fiber fabric

A novel technology to obtain high damping capacity in magnesium matrix composites was developed by designing a special interface layer. The interface layer was fabricated by coating a pyrocarbon on the surface of carbon fibers. Experimental results reveal that the carbon coating on carbon fibers may improve the overall damping of composite from room temperature to about 170 degreesC. The relevant damping mechanisms are ascribed to dislocation damping, interface damping and the intrinsic damping of the constituents. At temperature above 170 degreesC, the damping of the composite without the coating exceeds that with the coating owing to the contribution of interface damping and grain boundary damping.