Wear Characteristics under Boundary Lubrication Contacts in Phosphorated Starch Based Electrorheological Fluids

This experimental study presents wear characteristics under boundary lubrication contacts associated with electrorheolocal (ER) fluids composed of phosphorated starch particles and silicone oil. The ER fluids with different particle concentration by weight are adopted as lubricants. A pin-on-disc wear tester is then designed and manufactured to evaluate wear rates of pin specimens. Specimens used for the experiments include stainless steel, copper and aluminum pins. The wear tests of the ER fluids are experimentally performed under consideration of several factors such as normal load, sliding speed and specimen materials. Subsequently, microscopic surface and roughness changes of the worn surface of the pin specimens are analyzed in order to validate the measured wear characteristics by using the scanning electron microscope (SEM) and surface profilometer. In addition, friction coefficients of the ER fluids are experimentally evaluated with respect to the considered factors.