Studv On Ni-ZTA Nano-comdosite Coating And Its Performance Of The Wear And Corrosion Resistance

Nano-oxide ceramic coatings have high hardness, good corrosion resistance and abrasionresistance, etc.By surface coating technology, nanooxide ceramic coating can be prepared on theworkpieces surface, which can improve the abrasion and corrosion properties of matrix materials,and increase its using life.The first, zirconia (ZrO2), alumina (Al2O3) and ZTA (ZrO2toughened Al2O3) nanopowderswere prepared by sol-gel method in this study, the factors of nano-powder agglomeration wasstudied, and the effect of PH values, reaction temperature and drying temperature on the sizesand dispersion of nanooxide were researched. Moreover, the influence of the electrosparkdeposition parameters (such as voltage and power etc.) on Ni based alloy was studied. It wasfounded that the best coating could be prepared at60V,900W and Ar protection. At last, ZrO2、Al2O3and ZTA powders were laser claded on Ni based coating, and the nanooxide-Ni basedalloy composite coatings were obtained. The influence of laser cladding parameters (such aspower and velocity) on ZrO2、Al2O3and ZTA nano-coating were also studied.As to the prepared composite coating, the hardness of Ni-ZrO2, Ni-Al2O3and ZTAcomposite coating increased3.8times,2.5times and1.4times over that of matrix by hardnessanalysis of coating surface and cross-section. While, the abrasive resistance Ni-ZrO2, Ni-Al2O3and ZTA composite coating increased1.64times,2.25times and1.71times over that of matrixby friction and wear test. At last, electrochemical corrosion tests were carried out at3.5%NaClneutral corrosive solution environment, and the results of Tafel curves and impedance analysisshowed that the corrosion resistance of the three kinds of Ni-nanooxide coating were better thanthat of matrix, and the corrosion resistance of Ni-ZTA composite coating was the best.