Powder-Assisted Thermal Treatment of Forged Al 6063 Alloy: Procedure and Preliminary Hardness Observations

Aluminium alloys are widely used in engineering applications because of their low density, good corrosion resistance and favourable mechanical properties. However, their relatively soft surface limits their use in sliding or abrasive environments. In this work, forged Al 6063 specimens were subjected to powder-assisted thermal treatment in two stages. In the first stage, aluminium and molybdenum powders were coated on the specimen surface, wrapped in aluminium foil and heated in a furnace at 550 degrees Celsius. In the second stage, aluminium, titanium and molybdenum powders were applied, the specimen was packed using aluminium foil and copper wire, and it was heated at a reported 600 degrees Celsius for approximately 8 to 9 hours. Surface hardness of the plain, untreated specimen and of the specimen treated with aluminium, titanium and molybdenum powders was evaluated by the Brinell method, using a 2.5 mm ball, a 62.5 kgf load and ten indentations per specimen. The recorded readings for the two specimens are numerically identical and give a mean of 275.49 BHN with a standard deviation of 10.42 BHN, which is far higher than values usually reported for Al 6063. The readings therefore could not be verified and do not demonstrate any hardness improvement.