Investigation on Dynamic Characteristics of Aluminum Metal Matrix Composites

Metal matrix composite processing allows the possibility of improving both mechanical and damping properties by selecting reinforcements which have high damping characteristics, hardness and strength. In this work, the effect of disperse SiC as passive agents on the dynamic properties such as damping ratio, loss factor and effect of damping factor on Al7075/Al₂O₃/SiC composite machinability was studied. The composite samples were fabricated as Al7075/5%Al₂O₃, Al7075/5%Al₂O₃/5%SiC, Al7075/5%Al₂O₃/10%SiC and Al7075/5%Al₂O₃/15%SiC as well subsequently experimented. The dynamic properties were found using free vibration test approach and the hysteresis loop method. Further, the machinability in end milling operation was accessed by experimentation with the surface finish as the parameter under scrutiny. The composite Al7075/5%Al₂O₃/5%SiC has better damping ratio comparing to others, also the composite with the best damping capacity produces a fine surface finish during machining. Due to the self damping characteristics of the composite reduces the chatter during machining process such that the surface finish and dimensional stability was improved on the machined components.