掺碳TiB_2薄膜/钢摩擦副的干摩擦磨损性能

Surface Modification of Cr12MoV Steel by Depositing C-Doped TiB_2 Films

采用室温磁控溅射技术成功地在钢(Cr12MoV)基材表面制备出TiB2/SiC双层薄膜及掺碳TiB2(TiB2-C)/SiC双层薄膜,SiC薄膜为中间层。研究了掺碳对TiB2薄膜组织结构和摩擦磨损性能的影响。结果表明:SiC薄膜与基材和TiB2,TiB2-C薄膜间都具有明显且呈梯度的元素扩散;掺入的C以sp3C-C和sp2C-C形式存在,即以类金刚石形式存在;与钢球(直径为4 mm)对摩、干摩擦条件下,TiB2薄膜和TiB2-C薄膜的磨损速率在105mm3/(m.N)级,掺C明显降低了薄膜的摩擦系数(从0.82降低到0.45,5 min)和对对摩件(钢)的元素转移。分析表明,摩擦磨损性能的提高主要是TiB2-C薄膜中的C起到了固体润滑作用所致。

The carbon-doped TiB2 films were deposited by magnetron sputtering on substrate of the Cr12MoV steel,covered with a SiC buffer layer.The impacts of the film growth conditions,including the SiC buffer layer,carbon content,and deposition rate on the mechanical properties of the surface modified steel were evaluated.The microstructures and phase structures of the C-doped TiB2 films were characterized with scanning electron microscopy,energy dispersive spectroscopy,Raman spectroscopy,and conventional mechanical probes.The results show that the SiC buffer layer markedly enhanced the interface adhesion,and C-doping significantly improved the mechanical properties of the steel.For instance,the C-doping reduced the friction coefficients from 0.82 to 0.45,after sliding the sample against a steel ball for 5 min under dry friction condition.Besides,C-doping also increased the wear resistance.Possible mechanisms were also tentatively discussed.