氟化六方氮化硼的制备及其作为水基添加剂的摩擦学性能

Preparation and Tribological Properties of Fluorinated Boron Nitride Nanosheets Water-based Additive

对NH4F氟源进行恒温磁力搅拌和球磨辅助氟化,制备出氟化氮化硼纳米片(F-BNNSs),在接触Ti6-Al-4V(TC4)/GCr15的条件下研究了六方氮化硼纳米片(h-BNNSs)和氟化氮化硼纳米片(F-BNNSs)作为水基润滑添加剂的摩擦学行为。结果表明,随着h-BN与NH4F的质量比从1∶2提高到1∶4这种水基润滑添加剂的平均摩擦系数先由0.3135降低到0.1435然后提高到0.2177。h-BN与NH4F的质量比为1∶3时的F-BNNSs12其摩擦系数和磨损率比h-BNNSs分别降低了55%和75%。基于磨损痕迹的分析结果表明,F-BNNSs12良好的减磨耐磨性能可归因于:1、纳米片层间相互作用的减弱使相对滑动变得容易;2、F-BNNSs12的不相称纳米棒-纳米片结构形成滚动摩擦使其润滑性能良好;3、F-BNNSs12沉积在摩擦副表面生成不连续的润滑膜,避免了与摩擦副的直接接触。

Hexagonal boron nitride(h-BN)is a typical layered structure material with enormous potential in the field of friction and lubrication.Fluorinated boron nitride nanosheets(F-BNNSs)were prepared by constant temperature magnetic stirring and ball mill-assisted fluorination using NH4F as fluorine sourced,while h-BN as raw material.Tribological behavior of hexagonal boron nitride nanosheets(h-BNNSs)and F-BNNSs as water-based lubricant additives were evaluated under Ti6-Al-4V(TC4)/GCr15 contact conditions.The results showed that when as water based liblicant additives,the F-BNNSs prepared with the mass ratio of h-BN to NH4F increased from 1:2 to 1:4,the resulted average coefficients of friction(COFs)varied from 0.3135 to 0.1435 to 0.2177.When the mass ratio of h-BN and NH4F was 1:3,the COFs and wear rate of F-BNNSs12 prepared were 55%and 75%lower than that of h-BNNSs,respectively.Based on the analysis of wear scars,it were found that the excellent friction reduction and antiwear performance of F-BNNSs12 can be attributed to three aspects:The weakening polar interactions between the nanosheet layers may facilitate the relative slidding;F-BNNSs12 incommensurate nanorodnanosheet structure may cause rolling friction and good lubrication performance;F-BNNSs12 deposited on the surface of the friction pair favour forminga discontinuous lubricating film,to alleviate the direct contact for the friction pair.