Tribological Properties Of Graphene As Lubricant Oil Additive On Textured Bronze Surface

Friction and wear are the main resons of mechnical parts failure.According to authorita tive statistics, nearly 50% the world energy consumption was caused by friction and wear. R educing the failure of equipment and energy consumption caused by friction and wear are a great challenge of today’s world. Graphene is a new material with unique structure and exce llent property attracting wide attention and research. But it is an entirely new aspect that gra phene as a lubricant additive used in lubrication field. Meanwhile, the surface texture techn ology, which can reduce the friction and wear by improving the tribological properties of th e contact surface, has also been extensively studied.In this paper, UTM-2 machine was used with ball-plate contact form and reciprocating movement. The experiment was carried out under different lubricating oils, the base oil and the graphene-based oil, at different temperatures and textured surfaces. Using XRD, infrared spectroscopy (FTIR), Raman spectroscopy (Raman), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) characterize the structure and morphology of the graphene. After the experiment, the worn scars were analyzed by optical microscopy (OM), two-dimensional profile, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX), hardness tester etc. In the end,this paper concluded the mechanism of the antifriction and antiwear action. Accordingly, the main conclusions can be drawn as following:1. At 25 ℃,60 ℃,100 ℃,150 ℃ conditions, the graphene-based oil has better anti-friction and anti-wear effect than the base oil no matter what the textured surface, especially at 60 ℃ and 100 ℃. In the PAO4 oil condition, the coefficient of friction and worn scars are large at 60 ℃ and 100 ℃. There are obvious furrows and slight layer peeling phenomenon exists on the worn scar surface. Further analysis can find the sign of oxidation reaction and fatigue wear and abrasive wear is the main wear mechanism. In the graphene-based oil, the coefficient of friction low and similar no matter what the temperature. The surface of the worn scar is smooth and delicate, which has no obvious signs of oxidation reaction.2. Under the PAO4 base oil and 25 ℃,60 ℃,100 ℃,150 ℃ temperature conditions, the surface tribological properties varied on different area ratio textured surfaces (0%, 5%, 10%,20%). There has low coefficient of friction and small worn scars at 25 ℃ and 150 ℃. Further analysis can find that the coefficient of friction and the size of worn scar decrease along the texture ratio increasing at 25 ℃ and 150 ℃, the 60℃ and 100℃ are contrary. Under the graphene base oil and 25 ℃,60 ℃,100 ℃,150 ℃ temperature conditions, the coefficient of friction and the size of worn scars are similar, and the 5% area ratio textured surface has the best tribological performance and 20% is the worst.3. Under the PAO4 base oil and 25 ℃,60 ℃,100 ℃,150 ℃ temperature conditions, the surface tribological properties varied on different angle arrangement (30　°,60 °, 90 °) textured surfaces. The 60° textured surface has the best anti-grindability no matter what the temperature because its smallest worn scar was observed by optical microscope. Under the graphene-based oil, the coefficient of friction and the size of worn scar are similar, but the 60°textured surface also show the best anti-grindability.