自愈合抗氧化热障涂层的制备、性能及其应用研究

发布时间：2018-06-22 00:20

本文选题：自愈合材料 + 热障涂层　；参考：《华中科技大学》2016年博士论文

【摘要】：热障涂层(简称TBC),是由三个部分组成：1)粘接层(简称BC),2)热生长氧化物(简称TGO)和3)陶瓷顶层(简称TC)。当TBC在高温下服役时,TGO才会生成。而在TGO生成的初期,TGO可以在一定的程度上起到抑制氧化物生长的作用,即可视为抗氧化涂层。但是随着TBC在高温下服役时间的延长,TGO不断生长并最终导致了涂层整体的破坏性剥落。TGO是造成TBC破坏的主要原因。近年来,有多种能够提高TBC抗氧化性与寿命的方法被报道。其中,根据科研人员报道可知,A1203(在1400℃时,其氧扩散系数为-10-12。cm2/s)薄膜具有良好的抗氧化性。另外,还有很多研究人员也得出了相似的结论,即A1203薄膜／涂层的确能在一定程度上提高TBC的抗氧化性。但是经过大气等离子喷涂技术(简称APS)设备喷涂态的A1203或者Al2O3/YSZ涂层,本征的就具备很高的孔隙率,这会导致涂层的抗氧化性降低。自愈合材料包括陶瓷材料,高分子化合物材料,金属材料和复合材料。正如其名字自愈合所表达的含义一样,在材料本身由于加热、受力、受到冲击或其他因素而造成了损伤时,自愈合材料具有能够修复自生的特性。目前,除了部分关于防腐涂层的自愈合材料应用的研究外,鲜有关于热障涂层方面的自愈合材料应用研究。自愈合材料具有提高涂层的抗氧化性的可能性,其原理是通过密封效应提高涂层的孔隙率,减少涂层中的氧扩散通道。在相关的研究中,NASA中心的研究者们研究了航空发动机高温部件上使用轻质自愈合陶瓷材料,并且通过研究得知SiC及其对应的氧化物能够有足够的塑性来阻止裂纹的扩展,同时也有自愈合的能力来密封裂纹并阻止氧的侵入。本课题组的前期研表明,TiC能够很好的实现自愈合功能,并且在防氚渗透涂层方面有很成功的应用。本文研究了基于TiC的自愈合涂层、基于SiC的自愈合涂层、Cr2O3-Al2O3共格抗氧化涂层和氮化抗氧化涂层的制备工艺,研究了这些抗氧化涂层对复合TBC的抗氧化性,抗剥落性,抗热循环性和抗热腐蚀性的影响。主要的结论如下所述：(1)TAZ20对应的成分(其成分为20 wt% TiC,40 wt% Al2O3和40 wt% YSZ)被认为是最适合做基于TiC自愈合涂层的成分。经过自愈合热处理后,TAZ20自愈合涂层中的孔隙率从9.96%下降至3.28%。经过成分优化设计可知,TAZ20自愈合热障涂层在1000℃下表现出最好的抗氧化性。其TGO生成面积为6.67%,仅为传统热障涂层TGO生成面积的50.11%。而经过1000℃热循环测试可知,在该条件下,TAZ20自愈合热障涂层的寿命大幅度提高。(2)首先,最适用与基于TiC自愈合热障涂层的TAZ20涂层厚度为10um左右,因为过厚的TAZ20涂层厚度会引起不必要的体积增生和体积应变,进而会导致涂层中的裂纹萌发和扩展。三层陶瓷层结构(TAZ20/YSZ/TAZ20)的TiC自愈合热障涂层在1100℃下具有最好的抗氧化性和抗热循环性。经过氧化,该涂层的氧化增重、氧化失重和寿命分别为同批次传统TBC的64.77%,48.91%和188.24%。在900℃的75 wt% Na2SO4+25 wt% NaCl热腐蚀实验中,三层陶瓷结构的TiC自愈合热障涂层也具有良好的抗热腐蚀性能。(3)SAZ10对应的成分(其成分为10 vol% SiC,45vol% Al2O3和45vol% YSZ)被认为是最适合做基于SiC自愈合涂层的成分。经过自愈合热处理后,SAZ10自愈合涂层中的孔隙率从9.39%下降至1.94%。而在诸多基于SiC的自愈合热障涂层中,SAZ10自愈合热障涂层在1100℃下表现出最好的抗氧化性。其TGO生成面积为37.11%,仅为传统热障涂层TGO生成面积的57.90%。而经过1100℃热循环测试可知,SAZ10的寿命为传统热障涂层的128.57%。(4)首先,最适用与基于SiC自愈合热障涂层的SAZ10涂层厚度为10um左右,因为过厚的SAZ涂层厚度会引起不必要的体积增生和体积应变,进而会导致涂层中的裂纹萌发和扩展。三层陶瓷层结构(SAZ10/YSZ/SAZ10)的SiC自愈合热障涂层在1100℃下具有最好的抗氧化性和抗热循环性。经过氧化,该涂层的氧化增重、氧化失重和寿命分别为同批次传统TBC的61.38%,38.87%和171.43%。在900℃的75 wt% Na2SO4+25 wt% NaCl热腐蚀实验中,三层陶瓷结构的SiC自愈合热障涂层也具有良好的抗热腐蚀性能。(5)本文创新性的设计了一种氮化TBC。在制备YSZ涂层之前,现在粘接层的表面进行氮化处理。由1]00℃高温氧化研究可知,该涂层的氧化增重和氧化失重分别为同批次传统TBC的85.90%和56.11%。其1100℃热循环寿命为传统TBC的123.33%。(6)本文创新性的设计了一种Cr2O3-Al2O3TBC。经学者研究,Cr2O3-Al2O3涂层具有较低的孔隙率,这意味着该涂层能够减少氧扩散的通道。另外,A1203具有良好的抗氧化性,它可以抑制TGO的生长。研究结果表明,由1100℃高温氧化实验可知,该涂层的氧化增重和氧化失重分别为同批次传统TBC的68.99%和63.92%。其1100℃热循环寿命为传统TBC的123.08%。
[Abstract]:The thermal barrier coating (TBC) is made up of three parts: 1) adhesive layer (BC), 2) hot growth oxide (TGO) and 3) ceramic top layer (TC). When TBC is in service at high temperature, TGO will be generated. In the initial stage of TGO generation, TGO can act as an antioxidant coating on a certain range, but it can be considered as an antioxidant coating. With the prolongation of the service time of TBC at high temperature, the continuous growth of TGO and eventually lead to the overall destructive exfoliation of the coating.TGO is the main cause of TBC damage. In recent years, a variety of methods to improve the antioxidant and life of TBC have been reported. Among them, according to researchers, A1203 (at 1400 degrees, its oxygen diffusivity) -10-12.cm2/s films have good antioxidant properties. In addition, many researchers have come to the same conclusion that A1203 film / coating can indeed improve the oxidation resistance of TBC to a certain extent. But after the spraying of A1203 or Al2O3/YSZ coatings by atmospheric plasma spraying (APS) equipment, the intrinsic properties are available. High porosity, which leads to a decrease in the oxidation resistance of the coating. Self healing materials include ceramic, polymer, metal, and composite. As its name is self healing, the material itself is damaged by heating, force, impact, or other factors. In addition to the research on the application of self healing materials for anticorrosive coatings, there are few studies on the application of self healing materials on thermal barrier coatings. Self healing materials have the possibility of improving the oxidation resistance of the coating. The principle is to increase the porosity of the coating by the sealing effect and reduce the coating in the coating. In the related study, researchers at the NASA center studied the use of light self healing ceramic materials on aero engine high-temperature components, and by studying that SiC and its corresponding oxides can be plastic enough to prevent crack growth and also have self healing ability to seal cracks and prevent oxygen. Intruding. The research group has shown that TiC can achieve self healing function well and has a successful application in the tritium permeation coating. This paper studied the self-healing coating based on TiC, the self healing coating based on SiC, the preparation process of the Cr2O3-Al2O3 CO oxidation coating and the nitriding antioxidant coating, and studied the oxygen resistance of these coatings. The effect of coating on the oxidation resistance, resistance to exfoliation, thermal cycling and thermal corrosion resistance of composite TBC. The main conclusions are as follows: (1) the corresponding components of TAZ20 (whose components are 20 wt% TiC, 40 wt% Al2O3 and 40 wt% YSZ) are considered to be the most suitable components based on the self healing coating based on TiC. After self healing heat treatment, TAZ20 self healing coating The porosity in the layer decreases from 9.96% to 3.28%. through optimization design. It is known that the TAZ20 self healing thermal barrier coating exhibits the best antioxidant activity at 1000 C. Its TGO area is 6.67%, only 50.11%. of the traditional thermal barrier coating TGO area, and the thermal cycle test of the TAZ20 self healing thermal barrier coating under this condition is known. (2) first, the thickness of the TAZ20 coating which is most suitable for TiC self healing thermal barrier coating is about 10um, because the thickness of the thick TAZ20 coating thickness will cause unnecessary volume proliferation and volume strain, and then lead to the crack germination and expansion in the coating. The TiC self healing heat of the ceramic layer structure (TAZ20/YSZ/TAZ20) of the coating is self healing heat. The barrier coating has the best antioxidant and thermal cycling performance at 1100 C. After oxidation, the oxidation weight increases, and the oxidation weight loss and life span are 64.77%, 48.91% and 188.24%. of the same batch of traditional TBC, 75 wt% Na2SO4+25 wt% NaCl hot corrosion test at 900 C, and the TiC self healing thermal barrier coating of the three layer ceramic ceramic structure is also good. Thermal corrosion resistance. (3) SAZ10 corresponding component (its components 10 vol% SiC, 45vol% Al2O3 and 45vol% YSZ) is considered the most suitable component based on SiC self healing coating. After self healing heat treatment, the porosity in the SAZ10 self healing coating decreases from 9.39% to 1.94%. and in a number of SiC self-healing thermal barrier coatings, SAZ10 self The healing thermal barrier coating shows the best antioxidation at 1100 C. Its TGO area is 37.11%, only 57.90%. of the TGO area of the traditional thermal barrier coating. Through the 1100 C thermal cycle test, the life of SAZ10 is 128.57%. (4) of the traditional thermal barrier coating, and the most suitable for the SiC self healing thermal barrier coating is 1 of the thickness of the coating of 1. About 0um, because the thick SAZ coating thickness will cause unnecessary volume proliferation and volume strain, which will lead to the crack germination and expansion in the coating. The SiC self healing thermal barrier coating of the three layer ceramic layer structure (SAZ10/YSZ/SAZ10) has the best antioxidant and thermal cycling resistance at 1100 C. Oxidation, the oxidation weight increase of the coating The oxidation weightlessness and life span are 61.38%, 38.87% and 171.43%. in the same batch of traditional TBC, 75 wt% Na2SO4+25 wt% NaCl hot corrosion test at 900 C. The SiC self healing thermal barrier coating of the three layer ceramic structure also has good thermal corrosion resistance. (5) this article innovatively designed a nitriding TBC. to be bonded before the preparation of the YSZ coating. The surface of the layer is nitridation. From the high temperature oxidation at 1]00 C, it is found that the oxidation weight gain and oxidation weight loss of the coating are 85.90% and 56.11%. of the same batch of traditional TBC, respectively, and the thermal cycle life of the traditional TBC is 123.33%. (6) of the traditional TBC. This article innovatively designed a kind of Cr2O3-Al2O3TBC. study by scholars, and the Cr2O3-Al2O3 coating has a lower level. Porosity, which means that the coating can reduce the channel of oxygen diffusion. In addition, A1203 has good oxidation resistance, and it can inhibit the growth of TGO. The results show that the oxidation weight gain and oxidation weight loss of the coating are 68.99% and 63.92%. of the same batch of TBC, and the thermal cycle life of the coating at 1100 degrees centigrade, respectively. 123.08%. of traditional TBC
【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TG174.4

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