Methods of Distributing the IF-WS₂ Modifier for Its Introduction into the Structure of the Al₂O₃ Aluminum Oxide Coating

The microstructures and structures of modified Al₂O₃/IF-WS₂ coatings prepared on aluminum substrates are studied. Amorphous Al₂O₃ oxide coatings are obtained on EN AW 5251 aluminum alloy using the electrooxidation process. The quality of the IF-WS₂ nanopowder is of great importance in the process of its introduction into the nanopores of the Al₂O₃ oxide coating. Commercial nanopowder tends to agglomerate, and without appropriate pretreatment, it is difficult to introduce it into the nanopores of the coating. To improve the degree of fragmentation of the IF-WS₂ nanopowder, an experiment was carried out to distribute the nanopowder in the presence of strong ultrasounds, and new conditions for introducing the powder into the nanopores were used. A two-level design of experiment (DOE) was used. The SEM examination made it possible to conclude that Method A contributed to a more even distribution of nanoparticles in the microstructure of Al₂O₃ coatings. GIXD analyses showed the presence of WO₃ derived from the IF-WS₂ modifier next to crystal structures derived from aluminum and WS₂. Modification of coatings using Method A resulted in surfaces with lower contact angles measured with polar liquids and higher surface free energy compared to Method B.