Ti / TiCrN nanometer multilayer coating impeller and preparation method thereof

The invention belongs to the field of corrosion-resistant pumps used in the chemical industry and for conveying various types of fluid media, and particularly relates to a Ti / TiCrN nanometer multilayer coating impeller and a preparation method of the Ti / TiCrN nanometer multilayer coating impeller. The impeller comprises an impeller base body which is made of 25 steel, wherein a high-hardness coating in a multi-layer mixed phase structure composed of nanometer TiCrN, CrTiN, TiN and CrN is arranged on the surface of the impeller base body, and a titanium transition layer is arranged between the impeller base body and the surface high-hardness coating. The specific technology comprises a pretreatment process, an ion cleaning process, a titanium transition layer settling process and the process of settling the surface high-hardness coating in the nanometer TiCrN-CrTiN-TiN-CrN multi-layer mixed phase structure. The Ti / TiCrN nanometer multilayer coating impeller can maintain quite high hardness, the toughness of the coating and the bonding strength between the coating and the base body can be enhanced at the same time, and therefore the shock resistant performance and the abrasion resistant performance of the coating are improved, and the service life of the impeller is prolonged. Compared with an existing impeller which is not coated with the coating, the impeller prepared through the preparation method has significantly improved the abrasion resistant performance and the corrosion-resistant performance.