Effect of ZnO-Mg coating on fluid flow dynamics and thermal performance in AISI 4140 steel

The AISI 4140 medium carbon steel, known for its excellent hardness and availability, is widely used for transferring oil, water, and high-pressure gas lines, as well as in automotive applications. Surface coatings play a crucial role in enhancing the performance of steels, particularly in industrial applications. Among the most effective coatings are those made from Magnesium (Mg) and Zinc Oxide (ZnO), which are known for their unique properties such as hydrophobicity, chemical stability, and the ability to modify surface roughness. ZnO-Mg alloy coatings are of particular interest due to their superior heat resistance compared to pure ZnO coatings, making them a promising choice for protective coatings on medium carbon steels. These coatings not only improve adhesion and resistance to chemicals and heat but also enhance the substrate’s electrical, magnetic properties. This makes them highly valuable in the thermal and automotive industries. In this study, the focus is on optimizing the deposition thickness of ZnO-Mg coatings to improve the thermal response of mild steel. The flow behavior and thermal resistance of ZnO-Mg coated surfaces on AISI 4140 steel were analyzed using Ansys software. Measurements of flow parameters, such as velocity and temperature, were taken to assess the impact of the coatings on the fluid flow across the surface, aiming to enhance the material's performance in industrial applications.