Investigating the effect of spray parameters on adhesion strength between aluminum coatings and polymeric substrate

Metallization involves applying a thin metal layer onto a substrate, typically through techniques such as thermal spraying. This process improves conductivity, durability, and aesthetic appeal, making it valuable in applications such as electronics, solar panels, and decorative coatings. In this study, flame thermal spray technique are used to metalize high-density polyethylene with an aluminum layer. Taguchi and ANOVA are used to investigate the effect of various parameters on the adhesion strength between aluminum layers deposited on high-density polyethylene (HDPE) substrates. DOE utilization has facilitated the identification of the effects of the flame thermal spraying parameters, such as the distance between the spray gun and substrate, the spray velocity, the powder feed rate, and the delay time, on the adhesion strength. The orthogonal matrix resulting from the Taguchi method corresponded to an L9 (34) matrix, which was utilized to decrease the number of experiments from 81 to 9. To attain optimal adhesion strength, it is essential to maintain a distance of 250 mm between the gun spray and the substrate, utilize a powder feeding rate of 15 g/minute, achieve a spraying velocity of 300 m/min, and implement a delay time of four minutes. The X-ray diffraction shows that there is no oxidation in the coating layer. Moreover, the aluminum layer shows good electrical conductivity (2.08×104 Ω-1.cm-1). Using Taguchi and ANOVA leads to optimizing processes efficiently with fewer trials, improving product quality by reducing variability, and making informed decisions on which factors to control for optimal performance.