| AVS 61st International Symposium & Exhibition | |
| Tribology Focus Topic | Friday Sessions |
| Session TR-FrM |
| Session: | Applications of Novel Materials in Tribology |
| Presenter: | Guang Wang, University of Windsor, Canada |
| Authors: | G. Wang, University of Windsor, Canada X. Nie, University of Windsor, Canada J. Tjong, Ford Motor Company, Canada |
| Correspondent: | Click to Email |
A linerless aluminum (Al) engine block has potential in reducing the weight of an automotive engine for improvement of the fuel economy. However, the Al cylinder surface of an aluminum engine block is not usually strong enough to withstand the sliding wear against piston rings. A few surface processing technologies are used to protect the surface of cylinders directly. Among them, plasma transferred wire arc (PTWA) thermal spraying coating is already popular. Plasma electrolytic oxidation (PEO) coating is also proposed for increasing the wear resistance of aluminum-silicon alloy (A356) and reducing the friction between the cylinder and piston. In this work, two different PEO coatings with a thickness of around 25mm were prepared, and a high speed pin-on-disc tribometer was used to study the tribological behavior of the coating at oil lubricant conditions. A cast iron sample was also used to do the same tribological tests for comparison. The coefficient of friction (COF) vs surface roughness (Ra: 0.2-0.8µm) and sliding speeds (up to 6.0m/s) were particularly studied. The results show that the COF significantly decreased with the increase of sliding speeds, and a smoother coating surface generally exhibited a lower COF. The roughness also influenced the descent rate of the COF significantly. The COF of the PEO coatings could be lower than that of cast iron. The study indicates that the Al-Si alloy with PEO coatings could be a feasible solution to reduce weight and improve fuel efficiency of an Al engine.