纳米金刚石对电沉积镍基复合镀层微观结构及抗磨性能的影响

利用直流电沉积技术制备了纳米和微米镍镀层,以及纳米金刚石增强镍基复合镀层,考察了纳米金刚石颗粒对纳米及微米镍基质的表面形貌、微结构、硬度及磨损性能的影响．结果表明：引入纳米金刚石使得微米镍镀层的硬度和抗磨性能显著提高;但引入纳米金刚石对纳米镍镀层硬度的影响不大,对镀层的抗磨性能则反而产生不利影响．

Effect of Nano-Diamond Particulates on the Microstructure and Wear-Resistance of Electrodeposited Ni-Matrix Coatings

The microcrystalline Ni- and nanocrystalline Ni-based composite coatings incorporated with diamond nano-particulates were prepared making used of electrodeposition. The effect of the nano-diamond particulates on the surface morphology, microstructure, hardness, and wear-resistance of the two types of Ni-matrix coatings were investigated. Thus the Ni-matrix coatings with and without the nano-diamond particulates were characterized by means of X-ray diffraction and scanning electron microscopy. The friction and wear behaviors of the coatings sliding against AISI1045 steel under unlubricated condition in a ball-on-disc configuration were evaluated using a UMT-2MT friction and wear tester. The worn surfaces morphologies of the coatings were also analyzed by means of scanning electron microscopy. It was found that the incorporation of the nano-diamond particulates contributed to greatly increase the hardness and wear resistance of the microcrystalline Ni-matrix coating, but it had little effect on the hardness of the nanocrystalline Ni-matrix coating. Moreover, the nano-diamond particulates were harmful to the wear-resistance of the nanocrystalline Ni-matrix coating. The increased wear-resistance of the microcrystalline Ni-matrix coating in the presence of the nano-diamond particulates was attributed to the dispersive strengthening effect of the nnaoparticulates, which helped to increase the ability of the coating to resist plastic deformation and adhesion as well.