Improving Wear Resistance of Mechanical Seal Using NI-P Electroless Coating

Abstract

Electroless nickel phosphor coating is an important technology in the field of industrial coatings which is widely used in many technical applications. The electroless nickel phosphorus layer has high hardness and corrosion resistance, making it ideal for multiple applications for example, automotive, aerospace and electronics industries. Sulfuric acid is an essential agent in many industrial processes. The corrosive and abrasive nature of sulfuric acid results in rapid wear of mechanical parts, resulting in frequent replacement, increased maintenance costs, and may cause environmental and safety issues. This work employed electroless Ni-P coating, which was effectively assigned to mechanical seal models. The Taguchi design array L9 was used to conduct the experimental work. Mechanical properties such as Vickers hardness and wear rate were measured at different heat treatment temperature, coating time and coating bath temperature. The coating thickness was measured using an optical microscope. The results showed that the hardness increased reaching peak as 653 HV at 400C° and coating time 4 hours. As for wear resistance, it was recorded the lowest value as 0.00060 under same conditions. Through SEM and XRD, the formation of NiP and Ni3P were found. ANOVA demonstrated that heat treatment temperature was the most effected factor that contributed to enhance both hardness and wear resistance, followed by coating time.

Keywords

• ni-p coating
• wear
• sulfuric acid
• electroless coating
• mechanical seal