A study on the effect of TiO2 particulate reinforcement on corrosion behaviour of Al-6063 based compositesAuthor(s): V.Bheema Raju, H.C.Ananda Murthy, H.B.Lokesh
The corrosion behaviour ofAl 6063 alloy- TiO2particulate composites have been studied in the present investigation, in acidic and alkaline media. The unreinforced matrix, as well as the composites containing 2, 4 and 6% by weight of TiO2 particulates were prepared by liquid metallurgy route using vortex technique and their corrrosion behaviour was evaluated by weight loss method and galvanostatic polarisation methods. The corrodents used were 1NHCl, 1NNaCl, 1NNaOH. and equimolarmixture of 1NNaOHand 1N NaCl. The highest corrosion rate was observed in the case of corrodent 1N NaOH. The rate of corrosion of both the matrix alloy and the composites decreased with increase in time of exposure in variousmedia.When TiO2 is added to matrix, it exhibits insulator action towards corrosion medium and thereby reduces the percentage of pits and cracks formation. The Icorr values ofAl6063 Matrix alloy andAl6063/TiO2 composites were found to decrease as the TiO2 content increased from0%to 6%in allmedia,which could be attributed to particulates acting as physical barrier to the initiation and growth of pits during corrosion.