Formation and characterization of self-lubricated carbide layer on AA6082 Al-Mg-Si aluminum alloy by electrical discharge alloying process
(1. Department of Materials Science and Engineering, National Chung Hsing University, 145 Xingda Rd., South Dist., Taichung City 40227, China;
2. Department of Mechanical Engineering, Far East University, Zhonghua Rd., Xinshi Dist., Tainan City 74448, China)
2. Department of Mechanical Engineering, Far East University, Zhonghua Rd., Xinshi Dist., Tainan City 74448, China)
Abstract: The surface modification on the AA6082 Al-Mg-Si aging-hardenable aluminum alloy was investigated by electrical discharge alloying (EDA) process. Kerosene, used as a dielectric fluid, was pyrolytically decomposed into carbon for the formation of a self-lubricated carbide layer on the aluminum alloy surface during EDA process. Transmission electron microscopy (TEM) image found that the self-lubricated carbide layer was a multi-phase material with carbides and graphite. As a result, the EDA-modified aluminum alloy had a negligible wear rate of ~2′10-4 mg/m (c. f. ~1.1′10-2 mg/m for aluminum alloy substrate). Notably, a new characteristic was found that the EDA-processed carbide layer was a soft magnet, which improved the electromagnetic interference (EMI) shielding performance of the alloy.
Key words: Al-Mg-Si aluminum alloy; surface modification; electrical discharge alloying; self-lubricating; pyrolytic carbon; electromagnetic interference shielding