【摘要】：高溫紅外輻射材料區(qū)別于日常生活中經(jīng)常見到的常溫紅外輻射材料,后者輻射波段集中在遠紅外區(qū)域,主要用于織物和食品干燥等。而高溫紅外輻射材料在高溫條件下長期服役,要求材料本身在近紅外和中遠紅外波段具有較高的輻射率,并能滿足一定的使用性能。目前,關(guān)于紅外輻射材料的研究熱點主要集中在尖晶石結(jié)構(gòu)這類物質(zhì)上,本文也是主要針對這類結(jié)構(gòu)材料研究制備高性能陶瓷涂層。本實驗室以Cr2O3、NiO作為主要成分制備紅外輻射材料,并陸續(xù)分別研究制備了非金屬氧化物和稀土摻雜的復(fù)合材料。結(jié)合實驗室以往的研究方向,本次實驗將繼續(xù)以Cr2O3、NiO作為所選材料討論添加物對體系結(jié)構(gòu)及紅外輻射率的影響,并制備出性能更加完善的新型復(fù)合材料。實驗主要分為三個部分,第一部分是探究造粉工藝,優(yōu)化團聚粉末的流動性,第二部分是制備陶瓷涂層并初步探討Co3O4、MnO2、TiO2單種材料對體系紅外輻射率的影響,第三部分是實驗方案設(shè)計及性能檢測,通過對實驗數(shù)據(jù)的分析,確定了涂層中各組成物對紅外輻射率的影響。本文制備涂層主要工藝流程為:先將配好的粉末制備成料漿,經(jīng)過砂磨工藝減小原始顆粒尺寸,然后將最終料漿送入霧化盤霧化,在干燥塔內(nèi)高溫作用下得到復(fù)合團聚粉末。之后將團聚粉末在不同溫度段下處理,最后得到噴涂粉末。采用等離子噴涂工藝,通過送粉器將最終得到的復(fù)合團聚粉末沉積在基片表面,獲得滿足使用要求的高溫紅外輻射涂層。利用馬爾文粒度分析儀測試料漿粒度范圍分布,采用FL4-1霍爾流速計測量團聚粉末的流動性及松裝密度,綜合分析得到最優(yōu)的砂磨時間范圍在45min左右。對噴霧干燥后的粉末樣品進行SEM電鏡掃描發(fā)現(xiàn),噴涂前的焙燒工藝對粉末的流動性產(chǎn)生了一定的影響,粉末顆粒雖同樣呈現(xiàn)球形,但表面有許多凹凸不平的區(qū)域出現(xiàn),另外,采用等離子淬火工藝制備的粉末球形度完好,顆粒更加密實,表面也更加光滑,流動性最佳。采用TG-DSC測試方法,確定了焙燒粉末的兩個重要溫度點,450℃為本次實驗所采取的第一溫度點,主要用于粘接劑的揮發(fā),1400℃為第二溫度點,此溫度下保溫得到實驗所需的尖晶石結(jié)構(gòu)。對涂層進行XRD分析發(fā)現(xiàn):當(dāng)原料為Cr2O3、NiO、Co3O4、MnO2、TiO2五種成分時,形成了多種反尖晶石及混合尖晶石結(jié)構(gòu),涂層的紅外輻射率經(jīng)質(zhì)檢中心測試,在800~1000℃范圍內(nèi)均高于0.91,最高可達到0.92。制備的涂層具有良好的熱穩(wěn)定性和較好的結(jié)合強度。
[Abstract]:The high temperature infrared radiation material is different from the normal temperature infrared radiation material which is often seen in daily life. The latter radiation band is concentrated in the far infrared region and is mainly used in the drying of fabric and food. However, the high temperature infrared radiation materials have long service under the high temperature conditions, which requires that the materials themselves have a higher emissivity in the near and far infrared bands and can meet certain performance. At present, the research focus of infrared radiation materials is mainly on spinel structure, and the preparation of high performance ceramic coatings is also focused on this kind of structural materials. Infrared radiation materials were prepared by using Cr2O3,NiO as the main component in our laboratory, and non-metallic oxides and rare-earth doped composites were prepared respectively. Combined with the previous research direction of the laboratory, Cr2O3,NiO will continue to be used as the selected material to discuss the effects of additives on the system structure and infrared emissivity, and a new composite material with more perfect properties will be prepared. The experiment is mainly divided into three parts. The first part is to explore the powder making process and optimize the fluidity of agglomerated powder. The second part is to prepare ceramic coating and discuss the influence of Co3O4,MnO2,TiO2 single material on the infrared emissivity of the system. The third part is the design of the experimental scheme and the performance test. Through the analysis of the experimental data, the influence of the composition of the coating on the infrared emissivity is determined. In this paper, the main process of coating preparation is as follows: firstly, the slurry is prepared by mixing the powder, then the original particle size is reduced by the grinding process, and then the final slurry is sent into the atomizing disk to atomize, and the composite agglomerated powder is obtained under the action of high temperature in the drying tower. The agglomerated powder was then treated at different temperatures and the spray powder was obtained. The final composite agglomerated powder was deposited on the substrate surface by plasma spraying process and the high temperature infrared radiation coating was obtained by powder feeder. The particle size distribution of slurry was measured by Ma Erwen particle size analyzer and the fluidity and loose density of agglomerated powder were measured by FL4-1 Hall velocity meter. The optimum grinding time range was found to be about 45min by comprehensive analysis. SEM scanning electron microscopy showed that the roasting process before spraying had a certain effect on the fluidity of the powder. Although the powder particles were also spherical, there were many uneven areas on the surface. The powder prepared by plasma quenching has the advantages of perfect sphericity, more dense particles, smoother surface and the best fluidity. Two important temperature points of calcined powder were determined by TG-DSC method. The first temperature point was 450 鈩，

本文編號：2343940