Effect of nitriding on corrosion behaviour of graphite reinforced aluminium alloy composites

摘要

The paper evaluates the effect of nitriding treatment on the corrosion behaviour of graphite reinforced aluminium alloy 6061 composites. The composites were prepared using the liquid metallurgy technique. The graphite content in the composites was varied from 1 to 7% (by weight) in steps of 2%. The nitriding process was carried out at 500℃ for 24 h. Energy dispersive X-ray analysis was used to confirm the implantation of nitrogen in the composites. Three categories of specimens, namely, the nitrided composites, non-nitrided composites as well as non-nitrided and unreinforced specimens, were tested. Immersion corrosion test using the weight loss method was employed to study the effect of corrosion over a period ranging from 24 to 120 h in steps of 24 h at ambient temperature. The test solution used was aerated 1 N NaCl acid. It was observed that the nitrided specimens exhibited less weight loss compared to the non-nitrided specimens in general. The composites with greater content of graphite exhibited low corrosion rate.