Study On Preparation And Properties Of RE₂O₃ Doping Modified HfO₂ Based Infrared Ceramic Coating

The infrared radiation materials are widely used in such fields as infrared heating,infrared medical treatment,functional materials.And high temperature infrared radiation material demands at infrared wavelengths with high radiation and absorption capacity,also requires materials has the ability of resistance to high temperature,and meet in some such as nuclear industry,aerospace and other fields of high temperature environment to steady long-term service performance requirements.At present,the domestic for high temperature infrared radiation materials research focus on spinel series of infrared radiation material,but because of the limitation of material itself,its temperature is highest do not exceed 1600?.So this article is not constrained by spinel system,rationally choosing new UHTC composite,doping modification,to improve absorption materials in near infrared band,increasing the using temperature to more than 2000?.This thesis selects the ultra high temperature ceramic HfO₂ as the base material to the preparation of high temperature infrared radiation material,which can meet the needs of material under high temperature.In material preparation technology,took a series of experiments for the preparation technique of the system.On the optimization of material performance,by adding rare earth oxide?RE₂O₃?was prepared by high temperature solid phase reaction hafnium with the mixture of rare earth oxide crystals,improves the materials in near infrared wave band infrared emissivity.And on this basis,the selected suitable for adding in the system of praseodymium oxide(Pr₆O₁₁),terbium oxide?Tb₄O₇?,and other rare earth oxides added group,add to a moderate amount of hafnium carbide with high emissivity?HfC?,boride hafnium?HfB₂?oxide,thus further improve the high temperature infrared radiation performance of materials,and the influence of the comprehensive analysis of various additives on the properties of ceramic materials.Using the hall FL4-1 type flowmeter measurement to measure before and afterhigh temperature solid phase reaction reunion powders of liquidity and the apparent density,found reunion type powder liquidity after high temperature roasting and apparent density declined,but still in the meet the requirement of plasma spraying process.By SEM observation before and after high temperature roasting reunion type and powder coating surface morphology,found that the powder after high temperature reaction,powder surface become rough,reunited after high-expansion photos of observed surface of powder from the original small and uniform particle size of powder particles into with angular crystal structure,and the coating is of a typical layered stack structure,and the surface is bright and no obvious holes.Test material of high temperature infrared radiation rate is found,praseodymium oxide to add group has higher heat infrared emissivity,in addition,through the hafnium carbide and boride hafnium add,find hafnium carbide added at room temperature can not only improve powder and coating of the short-wave infrared emissivity,infrared radiation rate at high temperature is better.By XRD analysis found that praseodymium oxide addition to form new Pr₂Hf₂O_x and hafnium,so as to improve the infrared emissivity of the material.