二维层状Ni/β-Ni(OH)2纳米复合材料的制备及其摩擦学性能研究

Preparation and Tribological Properties of Two-dimensional Layered Ni/β-Ni(OH)2 Nanocomposite

采用水热反应制备出β-Ni(OH)2,然后通过水热还原得到Ni/β-Ni(OH)2纳米复合粉体材料,采用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对复合材料的相结构、成分及形貌进行表征分析。采用四球摩擦磨损试验机评价制备的Ni/β-Ni(OH)2作为润滑油添加剂的摩擦学性能,基础油为PAO6。摩擦试验后,采用SEM分析典型试验钢球磨斑的表面形貌,利用能谱仪(EDS)研究磨斑表面化学元素的组成,探讨Ni/β-Ni(OH)2纳米复合润滑添加剂的减摩抗磨机制。结果表明:Ni/β-Ni(OH)2纳米复合材料作为润滑添加剂具有极好的减摩抗磨性能,显著优于基础油PAO6和未负载纳米Ni的二维β-Ni(OH)2层状材料;与基础油相比,添加0.1%质量分数Ni/β-Ni(OH)2添加剂的油样的摩擦因数和磨斑直径分别降低了17.6%和41.5%;Ni/β-Ni(OH)2纳米复合粉体综合了纳米Ni及层状β-Ni(OH)2两部分结构特性,在摩擦过程中,复合材料中的纳米金属粒子Ni与层状结构材料β-Ni(OH)2能够相互增强起到协同润滑作用。

β-Ni(OH)2 was prepared by hydrothermal reaction,and then by hydrothermal reduction,Ni/β-Ni(OH)2 nanocomposite was obtained.The phase structure,morphology and chemical composition of the as-prepared nanocomposites were characterized by XRD and SEM.The friction and wear properties of the nanocomposite as lubricant additive in PAO6 based oil were evaluated by a four-ball tribo-meter.After tribo-test,the surface morphology and chemical composition of the wear surfaces on the contact steel balls were analyzed by SEM and energy dispersive spectrometer(EDS)to illustrate the anti-wear and friction-reducing mechanism of the resulting Ni/β-Ni(OH)2 additive.The results show that Ni/β-Ni(OH)2 nanocomposite as lubricant additive exhibits superior anti-wear and friction-reducing ability.The tribological properties of the oil dispersed with Ni/β-Ni(OH)2 nanocomposite are much better than that of the based oil and the oil dispersed withβ-Ni(OH)2.The friction coefficient and wear scar diameter of the oil dispersed with 0.1%Ni/β-Ni(OH)2 are reduced by 17.6%and 41.5%respectively,as compared to the PAO6 oil.The superior tribological properties of Ni/β-Ni(OH)2 are ascribed to the special composite structure from the nanocomposite,the nano-Ni and layeredβ-Ni(OH)2,which leads to synergistic lubricating action produced between nano-Ni andβ-Ni(OH)2.