Microstrutural Characterization And Tribological Behaviors Of Ti₃C₂T_x Two-Dimensional Nanosheets

In order to meet the requirem of high-performance lubrication additives in base oil,in this paper,two-dimensional Ti₃C₂T_x nanosheets were prepared by HF etching treatment and the prepared Ti₃C₂T_x nanosheets were treated by intercalation.These Ti₃C₂T_x nanosheets obtains difficult interlayer of K-Ti₃C₂T_x,Li-Ti₃C₂T_x and D-Ti₃C₂T_x.The twodimensional Ti₃C₂T_x nanosheets were characterized by X-ray diffractometry,SEM,TEM,and X-ray photoelectron spectroscopy.The effects of the preparation proces on the microstructure and chemical composition of the Ti₃C₂T_x nanosheets prepared by HF etching treatment and the prepared Ti₃C₂T_x nanosheets treated by intercalation was clarified.The tribological properties of Ti₃C₂T_x nanosheets as additives in base oil were investigated using a UMT-2 ball-ondisc tribotester.The effect of load,concentration and interlayer spacing on tribological properties was analyzed.The results show that,the exfoliation degree of Ti₃C₂T_x nanosheets is increased with increasing etching temperature.Among the process conditions investigated in this paper,the optimum HF treatment is to conducted at 65? for 5 h.The analyses of microstructure reveal that,both the HF treated Ti₃C₂T_x nanosheets and the intercalated Ti₃C₂T_x nanosheets have the two-dimensional layered structural morphology with hexagonal crystalline structure.After intercalation,the interlayer space value of nanosheets has a descending sequence of D-Ti₃C₂T_x,Li-Ti₃C₂T_x,and K-Ti₃C₂T_x.The results of tribological tests indiate that the average friction coefficient and wear rate of Ti₃C₂T_x nanosheets and intercalated Ti₃C₂T_x nanosheets have a tendency to decrease first and then increase with increasing of load and addition.Results indicate that the Ti₃C₂T_x nanosheets prepared by HF etching treatment and the intercalated Ti₃C₂T_x can greatly enhance the friction-reducing and anti-friction properties of base oil,especially with 1.0 wt% under 5 N load.Intercalated Ti₃C₂T_x nanosheets have a lower average friction coefficient and wear rate than unintercalated Ti₃C₂T_x nanosheets,which have a stronger effect on the friction surface.The average friction coefficient and wear rate of Ti₃C₂T_x nanosheets decrease with increasing of interlayer spacing...