轴表面DLC涂层对滑动轴承润滑承载性能的影响*

为研究轴表面类金刚石(DLC)涂层对滑动轴承承载性能的影响,利用滑动轴承实验台测试轴线对中及倾斜工况下灰铸铁、铝合金和聚酰亚胺(PI)涂层轴承分别与40Cr钢轴和DLC涂层轴配合时的轴心轨迹和极限载荷,并测试3种材料与40Cr钢和DLC涂层的摩擦因数。结果表明:相较与40Cr钢配合,灰铸铁和铝合金与DLC涂层配合时摩擦因数减小,重载下轴承偏心率减小,轴线对中工况下灰铸铁轴承的极限载荷超过10 MPa,铝合金轴承的极限载荷增大到7.8 MPa(增大1.1倍),轴线倾斜工况下轴承抱死失效时边缘变形增大;但重载下PI涂层与DLC涂层配合时摩擦因数增大,轴线对中工况下轴承极限载荷减小至3.6 MPa(减小44%),轴线倾斜工况下轴承抱死失效时边缘变形减小。

Influence of DLC Coating on Shaft Surface on Load Carrying Capacity of Sliding Bearings

To study the influence of diamond like carbon (DLC) coating on shaft surface on the load carrying capacity of sliding bearings,the journal center locus and seizure loads of gray iron,aluminum alloy and polyimide (PI) coating bearings with 40Cr steel shaft and DLC coating shaft under both aligned and misaligned conditions were investigated by a sliding bearing test rig.The friction coefficients of different friction pairs were also tested.Results show that compared with the results with 40Cr steel,the friction coefficients of gray iron and aluminum alloy with DLC coating decrease,and the eccentricity ratios of the two kinds of bearings under heavy load decrease.The seizure load of gray iron bearing with DLC coating shaft under aligned condition exceeds 10 MPa,and that of aluminum alloy bearing reaches 7.8 MPa (increases by 1.1 times).The deformation of the two kinds of bearings when seizure happens under misaligned condition increases.Under heavy loads the friction coefficient of PI coating with DLC coating increases,the seizure load of PI coating bearing under aligned condition decreases to 3.6 MPa (decreases by 44%),and the deformation when seizure happens under misaligned condition decreases.