Cr–C/h-BN 自润滑复合镀层的制备与摩擦学性能

Preparation and tribological properties of self-lubricating Cr–C/h-BN composite coating

在三价铬Cr–C镀液中添加1~5 g/L的h-BN自润滑微粒,运用直流电沉积技术在Q235碳素结构钢基体上制备了Cr–C/h-BN复合镀层。利用扫描电镜(SEM)、X射线衍射仪(XRD)、显微硬度计、摩擦磨损试验机等设备分析了h-BN微粒添加量、电流密度等工艺参数对镀层组织和性能的影响。结果表明:在电流密度20 A/dm2,h-BN添加量3 g/L的条件下,可获得h-BN微粒体积分数为6.15%的复合镀层。h-BN微粒的添加改善了Cr–C合金镀层的耐磨性,Cr–C/h-BN复合镀层在室温干摩擦条件下的磨损率减少了22%,平均摩擦因数由原先的0.49降低至0.31。

Cr–C/h-BN composite coatings were prepared on Q235 carbon structural steel by direct-current electrodeposition in a trivalent chromium bath containing 1-5 g/L of self-lubricating h-BN particles.The effects of process parameters such as h-BN particle dosage and current density on the microstructure and properties of the coating were analyzed using scanning electron microscope(SEM),X-ray diffractometer(XRD),microhardness tester,and friction and wear testing machine.The results showed that a composite coating with 6.15vol.%of h-BN particles could be electroplated with 3 g/L of h-BN particles in the bath at a current density of 20 A/dm2.The incorporation of h-BN particles improved the wear resistance of Cr–C alloy coating.The wear rate of Cr–C/h-BN composite coating was reduced by 22%under dry friction condition at room temperature,and its average friction factor was reduced from 0.49 to 0.31.