Tribological behavior of alumina (Al2O3) and zirconia (ZrO2) plungers used in high pressure pumps

Abstract

Ceramic materials are commonly used in plungers due to high resistance to wear, abrasion, and low coefficient of thermal expansion. Also, they are commonly used in dry conditions without permanent damage, ceasing of pump head and better corrosion resistance than metals due to their inert characteristics. Zirconia (ZrO2) ceramic is used due to its high strength whereas, alumina (Al2O3) is commonly used in industries for high pressure pumps. The toughness of zirconia ceramics is higher than alumina ceramics as it overcomes the inherent brittleness of ceramic materials. It also has higher wear resistance and extends the life of the product. Whereas alumina has better mechanical characteristics such as hardness compared to Zirconia. In this research work tribological behavior of Alumina and Zirconia ceramics used in high pressure pumps have been studied. The wear test using end face wear testing apparatus has been conducted under flat contact for both alumina and ceramic material considering a mean contact pressure of 10 N, 20 N, 30 N and 40 N and sliding velocity of 40 mm/s. The wear test was conducted for 30 min considering a total sliding distance of 1500 m and 3000 m. The wear test results indicate that both alumina and ceramic exhibit lower wear factors and superior mechanical properties. The findings also reveal that the wear rates of Al2O3 and ZrO2 are influenced by friction forces, subsequently impacting the overall wear rate. Also, as the load increases the surface contact area also increases which in turn increases the wear rate. However, zirconia could be a potential substitute for alumina due to its high strength and fracture toughness.