Effect of static and dynamic ageing on friction and wear behaviour of aluminium 6082 alloy

In recent past, warm forming processes have been used successfully to increase the strength of age-hardenable alloys by dynamic precipitation. However, the influence of dynamic age hardening on the wear and friction behaviour of age-hardenable aluminium alloy is not clear. Therefore, in the present investigation the effect of static and dynamic ageing on the friction and wear behaviour of aluminium 6082 alloy (AA 6082) sliding against tool steel (TS) surface has been studied. The aluminium samples used in the present study were in as-cast, solitionised and peak aged conditions. Optical microscope revealed the presence of dendritic structure in both as-cast and solitionised samples. Scanning electron microscope analysis of the debris and worn surfaces revealed the wear mechanism and role of precipitates on the friction and wear results. At low temperature (40 C), the frictional behaviour of as-cast, solitionised and peak aged samples were similar. The wear rates at 40 C increased with increase in the amount of strain inside the specimens due to fine precipitations. At 180 C, a significant variation in the frictional behaviour of different specimens was observed. The wear rate of solitionised specimens at 180 C is higher compared to as-cast and aged specimens. The absence of hard phases at initial stage of the test and subsequent dynamic precipitates restricted to a thin layer were responsible for the increase in wear rate.<p>Godkänd; 2012; 20120618 (leopel)