Nano-doped Al <sub> 2 </ Sub> The O <sub> 3 </ Sub> To +13 Wt.% Of Tio <sub> 2 </ Sub> Plasma Sprayed Ceramic Coating And Applied Research

A new method of plasma spraying in which common micron powder for the plasma spraying, Al2O3+13%TiO2(AT13) is doped by nanoparticales ATI3 is provided in this research. A new field for plasma spraying is introduced. The study covers the dispersing of nonmaterial, the preparation of powders for plasma spraying, decision of parameters for plasma spraying process. The influence of various proportion of nanoparticales on the coating structure, mechanics and performance is investigated, and locale experiments have been held also.The experiments by means of SEM, XRD show that nanoparticales are homogeneously dispersed in water under the cooperation effect of ultrasonic and punchy stirring. After dispersing, nanometer hydrosol is blended by common spraying powders, which is often called green slurry. Subsequently green slurry is dehydrated, pressed, sintered, porphyrized, and sifted. Eventually microscale powder is covered homogeneously by nanometer particles and the powder can be used for plasma spraying. The process parameters are basically equal to the common ones, but the former efficiency has been improved. Compared with micro particles, nanoparticles possess the properties including lower melting point, higher surfacial energy, more multi-suspending bonds, more multi-crystal interfaces, more multi-interspaces and so on. After nanoparticles is doped, the distribution of elements in the coating changed from local segregation to homogeneity. Uncertain anionic absence compounds energy in the plasma spraying coating, and these compounds will increase when the weight percent ofnanoparticales added. Compared with the coating of the common powders for spraying, the open hole percentage, pylome numbers and remnant stress of the coating doped with 15% nanoparticles have respectively declined to 5.11%, 67.31%, 66.72% and the density, the combinative intensity, the microrigidity and the heat-vibrating cycle timeshave separatedly raised 1.64%, 19.14%, 22.22%, 42.86%. At the same time, the friction factor between coating and GCr grinded-loop decreases from 0.73 to 0.65, the bulling time of the coating prolongs from 2h to 32h, the desquamation time of fall-off prolongs from 30h to 75h. When the weight percent of nanoparticles increase to 30%, the net-like primary whisker emerges at the coating, and the fracture form of the coating changes from brittle intergranular fracture to flexible transgranular fracture.Compared with the common plasma spraying, the plasma spraying coating with 15% nanomaterials had much better economic and technologic indices. Although its cost increases 20%, its lifespan prolongs more than one times and the process operation is easy. In a word the locale application is ideal. Through the study of the application of doped nanoparticles to plasma spraying, a new method that can improve the performance of the coating by doping nanoparticles in common powders for spraying. A new field for wide industrialized application of nanomaterials is exploited.