Tribological Behaviors of Si3N4-hBN against PEEK with Precorrosion in Seawater

Abstract

In this article, the tribological behaviors of Si3N4-hBN composites and polyether ether ketone (PEEK) materials with precorrosion were investigated in seawater and deionized water, respectively. Si3N4-hBN composite represented a good seawater corrosion resistance, and a low corrosion rate of 0.0037 g/(m2·h) was obtained for Si3N4-hBN composites in seawater. The seawater absorption rate of PEEK material was about 0.726%, and the surface became rougher with precorrosion. Si3N4-hBN/PEEK pairs presented friction coefficients of around 0.20, and some reactive products (e.g., SiO2 and H3BO3) formed on the surface. When the hBN content was equal to 10 wt%, more smooth worn surfaces were presented. In addition, the Si3N4-10% hBN/PEEK pair presented the lowest and most stable friction behavior. There were few changes in the Si3N4-hBN and PEEK materials before and after immersion in deionized water. The friction coefficients of the Si3N4-hBN/PEEK pair were all lowered than 0.1 in deionized water. The corresponding wear rates of pins and discs were all below the order of magnitude of 10−6 mm3/Nm. The excellent tribological characteristics were attributed to ultrasmooth surfaces (originated from the tribochemical reaction).