多层碳键联石墨烯涂层的宏观摩擦磨损特性

石墨烯作为固体润滑剂具有重要应用价值，但目前宏观载荷下多层石墨烯涂层对微机电系统硅材料器件的保护作用尚待进一步探索。利用线性往复摩擦试验机，对硅基底上厚度约为 230 nm 的多层碳键联石墨烯(CBG)涂层进行常温高接触应力条件下的宏观摩擦磨损特性分析。试验结果发现：CBG 涂层显著降低了硅片表面的摩擦因数以及磨损程度。当载荷从 1 N (约 551 MPa)增加至 5 N(约 942 MPa)，摩擦因数均稳定在 0.12~0.18。进一步，在 5 N 大载荷作用下的 18 000 次往复摩擦中，摩擦因数仍基本维持在 0.2 以下，最低磨损率约为 5.0×10^?7 mm³ / (N·m)，有效验证了 CBG 涂层优异的宏观摩擦磨损性能。CBG 涂层上出现的块状碎片、剥离坑和连续划痕是磨损退化的基本缺陷形式，较高接触应力下磨损颗粒产生的犁削行为可能是涂层被逐渐剥落的主要原因。研究成果表明 CBG 涂层在宏观载荷下具有优异的减摩耐磨性能，可以揭示涂层的磨损过程和破坏机理。

Macroscale Tribological Properties of Multi-layer Carbide-bonded Graphene Coating

Graphene has important applications as a solid lubricant, but the protective effect of multi-layer graphene coatings on silicon devices in the MEMS under macroscale load remains to be further explored. The tribological properties of a multi-layer carbide-bonded graphene (CBG) coating on silicon substrate with a thickness of 230 nm are investigated under normal temperature and high contact stress, by using a reciprocating linear friction testing machine. The experimental results show that the CBG coating significantly reduce the friction factor and wear degree of the silicon surface. When the loads increase from 1 N (about 551 MPa) to 5 N (about 942 MPa), the friction factor are always stabilized between 0.12 and 0.18. Furthermore, the friction factor remains below 0.2 and the minimum wear rate is about 5.0×10^?7 mm³ / (N·m) in 18 000 cycles and under a heavy load of 5 N , which effectively verifies the excellent friction and wear properties of CBG coating at the macroscale. The bulk fragments, peeling pits and continuous scratches on the CBG coating are the basic defects of wear degradation, and the ploughing behavior of wear particles under high contact stress may be the main reasons for the gradual peeling-off of coating. The results show that CBG coating has excellent anti-friction and wear resistance under macroscale load, and reveal the wear process and failure mechanism of the coating.