Published online by Cambridge University Press: 21 February 2011
A novel process was developed to firmly coat an aluminium alloy, A16061, with α-A12O3 by means of laser processing. In this approach a mixture of SiO2 and Al powder was used to inject in the laser melted surface of aluminium. A reaction product α-A12O3 layer of a thickness of 100 μm was created which was well bonded to the aluminium surface.Various interfaces, A1/α-A12O3, Al/mullite and α-A12O3/;mullite, were studied by conventional transmission electron microscopy (CTEM) and high resolution electron microscope (HREM). It turns out that the presence of the A1/;muilite interface may be essential to form a well bonded oxide layer and the high Si-content α-A12O3 intermediate layer may be wetted better by liquid Al.