添加纳米TiO2的Ni-P化学复合镀层显微结构与性能

采用化学复合镀法制备了Ni-P-纳米TiO2复合镀层,研究了纳米TiO2添加对Ni-P复合镀层的显微结构、硬度、耐磨性、孔隙率及耐蚀性的影响,并讨论了其影响机理。结果表明:纳米TiO2粒子较为均匀地分布在Ni基镀层,未发生明显团聚;纳米TiO2粒子的弥散强化作用,使复合镀层具有较高的表面硬度和良好的耐摩擦性能,晶化热处理后的复合镀层表面硬度达到了10 925 MPa,耐摩擦性能也显著提高。添加纳米TiO2粒子后,镀层的孔隙率增加,耐碱和耐盐腐蚀的能力稍有降低,耐HCl溶液腐蚀的能力较差。

Microstructure and Properties of Ni-P Electroless Composite Coating Added with Nano-TiO2

Ni-P-(nano)TiO2 composite coating was prepared by electroless composite plating. The effects of nano-TiO2 addition on microstructure, hardness, wear resistance, porosity and corrosion resistance of Ni-P composite coating were investigated and the mechanism was discussed. The results show that TiO2 nanoparticles are homogeneously distributed in the Ni based coatings, without apparent aggregation. The dispersion strengthening effect of the nano-TiO2 particles leads to high hardness and good wear resistance of the composite coating. The surface hardness of the crystallized composite coating can reach 10925 MPa and the wear resistance increases greatly. However, nano-TiO2 particles addition increases the porosity of the coating, decreases the corrosion resistance to NaOH and NaCl solution slightly, and the corrosion resistance to HCl becomes poor.