The influence of the silicon phase on the wear behavior of aluminum-silicon alloys is subject of ongoing research. The present contribution focuses on the influence of the silicon grain size on the wear behavior of a hypoeutectic AlSi9Cu3 alloy.
The silicon grain size has been varied by the addition of strontium to the melting. Disks of refined and non-refined alloys were cast and tested on a pin-on-disk tribometer with steel pins in the ultra-low wear regime. Radionuclide technique was used to measure the pin wear in-situ with a resolution of a few nanometers per hour.
Comparison of wear track depth and also of pin wear rates didn’t show a significant difference. But the comparison of overall disk and pin wear shows that, for comparable pin wear, the disk wear of the refined system is lower. Disadvantage of the refined system is –compared to the non-refined system- its higher sensitivity, i.e. an increase in wear rate with a change of load and speed.