Characterisation of organic–inorganic hybrid coatings deposited on aluminium substrates

Optically transparent silica-based single amorphous phase organic–inorganic hybrid coating materials with differing organic/inorganic ratios have been prepared by a novel patented sol–gel process and deposited using a simple angled flow coating method on commercially pure aluminium substrates. Transmission electron microscopy and scanning electron microscopy were used to characterise the microstructures of the hybrid materials and the quality of the interfaces between the coatings and the aluminium substrates. The scratch resistance, critical load to failure and failure modes of these hybrid coating materials were studied using a simple scratch test. The coatings produced were all shown to adhere well to the aluminium substrates and exhibit good levels of scratch resistance.