Study On High-temperature Ceramic Catalyzed By Laser Excitation

High-temperature ceramic materials have attracted much attention on account of their excellent electrical and thermal properties,and their tremendous potential value has made them a research hotspot.Among the commonly used methods for preparing high-temperature ceramic materials,sol-gel method and chemical coprecipitation method have numerous steps and complicated processes,solid-reaction method is simple but time-consuming and energy-consuming.In order to improve the preparation efficiency of high-temperature ceramic materials,a laser excitation catalyze high-temperature ceramic materials technology with simple steps,short cycle and zero pollution was proposed in this paper.In this paper,the preparation,characterization,testing and analysis of high-temperature ceramic materials catalyzed by laser excitation are described in detail.Taking Yb₂O₃-ZrO₂ series of ceramic materials as research object,Yb₂O₃-ZrO₂ series high-temperature ceramic materials were successfully prepared by using Yb₂O₃ and ZrO₂ powders as matrix materials and 980nm laser beam as excitation energy.The resonance absorption effect of Yb³⁺ions in this wavelength was effectively utilized to stimulate solid-state reaction.When the laser power reaches to 400 W,the high-temperature ceramic?Yb₂O₃?_xZrO₂ with good single crystal structure can be obtained by laser sintering for 10s.The crystal phase of product will not be affected at higher laser power.With the increase of Yb content in?Yb₂O₃?_xZrO₂ ceramics,the X-ray diffraction peak shifted to lower angle slowly,and the spacing of?111?interface as shown by TEM increased from 0.296 nm to 0.299 nm slowly.?Yb₂O₃?_xZrO₂ solid solution of high quality is formed by laser excitation catalyzing.?Yb₂O₃?_xZrO₂ resultant was observed to be porous in SEM diagram.Obvious Raman peaks at 320cm^-1 and 615cm^-1corresponds to Zr-O and O-O bonds,which means Raman activity of?Yb₂O₃?_xZrO₂was enhanced.The lattice structure of?Yb₂O₃?_xZrO₂ changes from fluorite to pyrochlore.In particular,Yb_0.2Zr_0.8O_1.9 has a high peak at 615 cm^-1.Combining XPS analysis,it can be seen that the material contains a large number of oxygen vacancies,and its oxygen vacancies ratio is much higher than that of Yb₂Zr₂O₇.At 25? to 1200?,the thermal conductivities of Yb_0.2Zr_0.8O_1.9.9 high-temperature ceramic is in the range of 0.677 to 0.936 W??mK?^-1,the thermal conductivities of Yb_0.2Zr_0.8O_1.9.9 ceramic is in the range of 0.497 to 0.730 W??mK?^-1.The method of laser excitation greatly reduced the thermal conductivities of high-temperature ceramics.In addition,alternating current impedance shows that the grain conductivity of Yb_0.2Zr_0.8O_1.9 resultant is 1.352×10^-66 S??cm?^-1 at 500?,rich oxygen vacancies in ceramic gives rise to high medium temperature conductivity.Yb_0.2Zr_0.8O_1.9 synthesized by laser excitation has great application value in the field of solid fuel cell.