Properties of epoxy AI₂O₃-TiO₂ nanocomposite for welded steel corrosion resistance

Aluminum oxide, commonly known as alumina (Al₂O₃), finds widespread application in high-performance contexts owing to its commendable attributes such as high corrosion and wear resistance. Nevertheless, its low bending strength poses a challenge. To overcome this limitation, researchers propose reinforcing Al₂O₃ with materials like TiO₂ to bolster its properties. This study aims to synthesize epoxy Al₂O₃-TiO₂ composite powder via the powder metallurgy route and assess its properties with a milling time of 40 hours for the coating sample. The composite powder was produced through high-energy ball milling at a constant speed of 300 rpm for the specified duration. Subsequently, it was combined with epoxy to create coatings for welded steel and thin films. Phase identification and morphology analysis were conducted using X-ray diffraction (XRD) and scanning electron microscopy (SEM) respectively, while Fourier-transform infrared spectroscopy (FTIR) was employed for characterization. Crystal size and internal strain of Al₂O₃-TiO₂ were determined using the Williamson-Hall method. Additionally, coated welded steel underwent immersion in NaOH for 28 days to assess changes in weight loss, hardness, and thickness, measured using tools such as the Shor D gauge, thickness gauge, and scales. Following the 28-day immersion period, significant variations were observed among the samples. Notably, the sample with a composition of Al₂O₃-TiO₂ at 1wt% exhibited the lowest weight loss. Furthermore, the epoxy Al₂O₃-TiO₂ composite at 1wt% experienced the least decrease in thickness during the immersion period, with the hardness test indicating higher hardness compared to others. These findings underscore the potential of epoxy Al₂O₃-TiO₂ composites in enhancing material properties, offering valuable insights for various industrial applications.