Data-driven modeling of wetting angle and corrosion resistance of hypereutectic cast Aluminum-Silicon alloys based on physical and chemical properties of surface

In the present study, a data-driven approach was applied to study the effect of silicon percentage, surface roughness, elapsed time, and water droplet size on contact angle (CA) of hypereutectic cast Al-Si alloys. In addition, corrosion resistance of the alloys was studied as a function of silicon content and the surface roughness. A factorial design was utilized for the design of experiment, and statistical analysis, including General Linear Model (GLM) and Polynomial Regression, were performed for the interpretation of the CA values. Wenzel and Cassie-Baxter contact angles were also calculated and compared with the corresponding measured contact angles to study which regime was followed. The statistical analysis results show that surface roughness, droplet size, and elapsed time are significant factors in the variation of contact angle. In addition, CA was observed to increase with surface roughness, droplet size, and elapsed time. It was observed that the experimental CA values follow a quasi Cassie-Baxter regime in which CA increases by increasing surface roughness. Si % turned out to be a statistically non-significant factor. It is possibly due to a trade-off between the increase in CA as a result of a change in surface chemistry and decrease in CA because of the smoother surface of Si compared to the eutectic phase in a given surface finish.