Graphite copper sleeve has two, one is oil, medium lubricant; the other is inlaid solid lubricant, medium is solid lubricant (usually graphite or PTFE). Graphite has a layered structure. It slides between layers. It runs with the workpiece. The lubrication of solid lubricants and graphite transfers to the friction surface to form a lubricating film. Graphite copper sleeve itself has self-lubricating function. Of course, if you still use fuel, then the medium is copper-graphite+alloy+lubricant.
High Strength Brass of Graphite-Copper
High strength brass has good plasticity and can withstand cold and hot processing, but it is easy to be fragile by forged hot working temperature. The specific temperature range of brass ranges from 200 to 700 C with different zinc content. Therefore, the hot working temperature is higher than 700 C.
The mechanical properties of brass with high zinc content are different. The increase of alpha brass, zinc and b_delta increases. 45% alloy of graphite copper sleeve to zinc ratio. The hardness of standard high strength brass HB is more than 200, and its compressive strength is more than 600 MPa and its elongation is more than 10%.