An Anticorrosion Coating from Ball-milled Wood Charcoal and Titanium Dioxide using a Flame Spray Method

In coating technology, many coating methods have been developed to enhance metal’s resistance to corrosion. This study demonstrated the use of a simple, easy, and economical manual thermal flame spray method to create an anticorrosion coating layer composed of ball-milled wood charcoal (a readily-available source of carbon) and titanium dioxide (TiO2). The coating materials were sprayed and melted by passing them through a flame; they were then deposited onto the surface of metal substrate of structural steel (SS) 400. We observed that the surface layers of the substrate sprayed with the wood charcoal–TiO2 mixture contained deposits such as titanium carbide, as a result of the carbothermal reduction reaction between TiO2­­ and the carbon present in the wood charcoal, and other iron carbide and titanium-iron oxide compounds. This deposit layer may explain why this substrate also exhibited a microhardness of more than twice that of the uncoated substrate. The coated substrate shows a darker shade than the uncoated substrate. The observation under optical microscopes shows that the uncoated metal substrate has a rougher surface with many more voids than the coated substrate. The coated surface has a water contact angle of ~107o indicating that a hydrophobic surface can be maintained. The coated substrates also demonstrated greater corrosion resistance to both acid and water, with the wood c

In coating technology, many coating methods have been developed to enhance metal’s resistance to corrosion. This study demonstrated the use of a simple, easy, and economical manual thermal flame spray method to create an anticorrosion coating layer composed of ball-milled wood charcoal (a readily-available source of carbon) and titanium dioxide (TiO2). The coating materials were sprayed and melted by passing them through a flame; they were then deposited onto the surface of metal substrate of structural steel (SS) 400. We observed that the surface layers of the substrate sprayed with the wood charcoal–TiO2 mixture contained deposits such as titanium carbide, as a result of the carbothermal reduction reaction between TiO2­­ and the carbon present in the wood charcoal, and other iron carbide and titanium-iron oxide compounds. This deposit layer may explain why this substrate also exhibited a microhardness of more than twice that of the uncoated substrate. The coated substrate shows a darker shade than the uncoated substrate. The observation under optical microscopes shows that the uncoated metal substrate has a rougher surface with many more voids than the coated substrate. The coated surface has a water contact angle of ~107o indicating that a hydrophobic surface can be maintained. The coated substrates also demonstrated greater corrosion resistance to both acid and water, with the wood c