Research On Room-temperature And High-temperature Tribological Properties Of Particles Reinforced 8009 Aluminum Matrix Composites

8009 alloys were considered to be a suitable matrix to prepare aluminum matrix composites with good tribological properties due to its high specific strength,high creep resistance and good heat resistance.In this paper,SiC particle reinforced 8009aluminum matrix composites were prepared by a combination of powder metallurgy and hot extrusion.The room temperature friction and wear properties of SiC_p/8009composites were investigated by a ball-disk tester.The effects of applied load and rotation speed on the friction and wear properties of composites were analyzed;worn surfaces and wear debris were analyzed to reveal the wear mechanism.The high temperature friction and wear properties of SiC_p/8009 composites were investigated by a pin-disk apparatus.The effects of temperature and rotation speed on the high temperature friction and wear properties of the composites were analyzed;the worn surfaces and wear debris were also analyzed.The results of friction and wear at room temperature show ed that the friction coefficient of the composites went through a running-in period followed by a stable period as the increasing of sliding distance.The average friction coefficient of the composites decreased with the increasing of the applied load and the rotation speed;the wear rate of the composite increased with the increasing of the applied load.In the stage of mild wear I,the relationship between the wear rate and the applied load satisfied the Archard equation,namely the wear rate is proportional to the applied load;In the moderate wear stage II,the mechanical mixed layer was formed on the friction surface of the composites,and the wear rate appeared to be constant;In the severe wear stage III,the wear rate increased sharply due to the broken of the mechanical mixed layer.As the applied load increasing,the wear mechanism of the composites underwent oxidative wear accompanied by brasive wear,adhesive wear,and delamination wear.The results of high temperature friction and wear showed that the friction coefficient of composites went through a running-in period and followed by a stable period with the increase of sliding distance.At 200 rpm,the average friction coefficient of the composite increased with the increase of temperature while the wear rate decreased to a certain value and then increased with the increase of temperature.The increase of the average friction coefficient may be related to the increase of adhesion and the wear rate decreased due to the formation of oxide layer;at 300 rpm,the average friction coefficient of the composite increased first and then decreased with the increasing of temperature,and the wear rate decreased with the increasing of temperature.a mechanical mixed layer was formed on the surface of the composites;At 400 rpm,the average friction coefficient and wear rate of the composite s increased first and then decreased with the increasing of temperature due to the forming of a ribbon-like flow layer on the friction surface.At 80°C,with the increasing of rotation speed,the average friction coefficient of the composites increased first and then decreased while the wear rate decreased.When the temperature is increased to 110°C,the average friction coefficient of the composite decrease d and then increased while the wear rate increased first and then decreased with the increasing of the rotation speed.At 150°C,the wear rate and average friction coefficient of the composites decreased with the increasing of rotation speed.