电沉积纳米晶材料摩擦学尺寸效应研究

Grain Size Effect in Tribological Performance of Electrodeposited Nanocrystalline Ni

采用脉冲电沉积法制备了不同晶粒尺寸的纳米晶镍材料,实现了纳米晶粒的有效可控。考察了晶粒尺寸对纳米晶镍材料摩擦磨损性能的影响。结果表明:粗晶镍呈现严重的粘着磨损,随着晶粒的细化,硬度和强度的增加显著提高了镀层的抗塑性变形和抗粘着磨损的能力。电沉积镍具有明显的摩擦学尺寸效应,随着晶粒尺寸的减小,镍的磨损机制由粘着磨损逐渐转变为微磨粒磨损和氧化磨损,其摩擦因数逐渐降低,耐磨性显著增强。

Nanocrystalline Ni coatings with different grain size were prepared by pulse electrodeposition method. The effects of grain size on the tribological properties of nanocrystalline Ni were investigated. Results show that reduction of grain size to nanocrystalline increases the hardness significantly and thereby reduces the plastic defomation of nanocrystalline Ni. Wear mechanism of Ni coatings experience transition from severe adhesion wear and plastic deformation accompanied by delamination to a set of micro-abrasion and oxidation wear as a result of hardness increase. The electrodeposited Ni shows a decrease both in the friction coefficient and wear rate as a result of grain size reduction.