TiN/ZrO₂ multilayers synthesized on GCr15 bearing steel using plasma immersion ion implantation and deposition

TiN/ZrO₂ multilayers with different modulation periods were synthesized on GCr15 bearing steel using plasma immersion ion implantation and deposition (PIIID). The total thickness of the TiN/ZrO₂ multilayers was approximately 2 μm and the modulation period was varied from 8 to 400 nm. The as-deposited films were characterized by scanning electron microscopy (SEM), micro-hardness, friction, scratch and corrosion tests. The SEM result indicates that the structure of the TiN/ZrO₂ multilayers has a good periodicity. Micro-hardness testing results show that the hardness enhancement effect takes place at the specific period of 15 nm, 100 nm and 200 nm. In addition, the friction coefficient declined from 0.8 to 0.1-0.3 and the cut-through number was increased greatly. The critical load in the scratch test exceeds 100 N, which shows a high adhesion strength. Moreover, the corrosion resistance of the TiN/ZrO₂ multilayers was improved significantly at the modulation period of 100 nm and 200 nm.