Investigation on an Al/WC Composite Coating of A356 Alloy Fabricated by Mechanical Alloying

In this paper, Al/WC composite coatings on A356 alloy were prepared by mechanical alloying, and their mechanical properties were characterized. The processing parameters for mechanical milling treatment, such as the premixing process of Al and WC powders, the ball-to-powder weight ratio and the milling duration, have been optimized, and the optimum ball-to-powder weight ratio and milling time were determined to be 14:1 and 12 h, respectively. It was found that premixed Al and WC powders have no significant influence on Brinell hardness due to the powders adhering to the balls and milling tank wall. With the Al/WC composite coating, the Brinell hardness of A356 alloys can be significantly improved from 65 HBW to 115 HBW.