Effect of Processing Parameters on Al-AlN Metal Matrix Composites

摘要

Processing of aluminum alloy metal matrix composites reinforced with AlN particles using a novel chemical in situ technique involving reactive gas injection is reported. Effect of processing variables such as gas injection time, flow rate of gas has been studied and optimized for developing an economical industrial technique. Current research involves injection of ammonia as precursor gas in to A356 alloy melt. Experiments were conducted in a Lindbergh furnace at 1473K to produce Al-alloy composite with nitride content varying from 5 to 60wt%. Composition of the products is analyzed using Optical Microscope, XRD, SEM, and EDS techniques. A linear increase in nitride content with an increase in bubbling time was observed. Vickers hardness number (HV) and Knoop hardness number (HK) measured for these composites showed an increasing trend with increasing AlN content.