石墨烯作为水基半合成切削液添加剂的硬质合金-钢材料摩擦学特性分析

改善加工过程润滑条件是延缓刀具磨损的重要途径。将石墨烯作为3034水基半合成切削液的添加剂，研究石墨烯悬浮切削液的硬质合金-钢材料摩擦学性能，研究对象是由硬质合金YG8制备的金属球和由45#钢制备的圆盘形试件；采用球-盘摩擦副接触方式在摩擦磨损试验机上进行试验，测定了质量分数为0.1%～0.9%的石墨烯悬浮切削液的平均摩擦特性和摩擦系数；采用激光共聚焦显微镜对磨痕轮廓进行提取，并得出磨损定量评价指数，并用扫描电镜和拉曼光谱仪对磨痕进行磨损机理分析；进行切削实验来分析石墨烯悬浮切削液对切削性能指标的改善情况。实验分析结果表明：石墨烯悬浮切削液能明显改善硬质合金-45#钢之间的润滑条件，摩擦系数和磨损率显著下降，采用不同质量分数石墨烯悬浮切削液的平均摩擦系数较原半合成切削液下降12.9%～57.3%，磨损率下降33.82%，同时切削合力较原半合成切削液下降18.58%，加工后工件表面粗糙度下降7.5%。
Carbide with its products is extensively applied in the field of mechanical machining of metal materials. In this study, graphene was employed as a beneficial additive to semisynthetic cutting fluid 3034, and the related frictional characteristic behavior was investigated via experimental on carbide-steel friction pair. In the experiment, a ball specimen was made of the carbide material of YG8, and a disk was made of the steel material of 45#. On the basis of ball-on-disk friction pair, experiments were conducted on a tribometer machine. The mass fraction of graphene in the tested coolant ranges from 0.1% to 0.9%. Surface topologies of the specimen were investigated using a laser confocal microscope. The scanning electron microscope and Raman spectra analysis was used to analyze wear mechanism. Experimental results revealed the improvement of lubrication condition between carbide and steel is substantially improved, demonstrated by the decreasing of averaged friction coefficient by 12.9% to 57.3% as well as the decreasing of wear rate by 33.82%. The resultant cutting force was decreased by 18.58% compared with that of semisynthetic cutting fluid 3034, and the surface roughness was reduced by 7.5% of the machined workpiece.