CORRELATION BETWEEN DEFECT MORPHOLOGIES IN COATED FILM AND ENVIRONMENTAL DEGRADATION RESISTANCE OF PLASMA-SPRAYED CERAMIC COATINGS

等离子喷涂陶瓷涂层涂膜缺陷形貌与耐环境降解性的相关性

• 批准号: 07455057
• 负责人: KIMURA Yuji
• 金额: $ 3.58万
• 依托单位: KOUGAKUIN UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07455057/
• 关键词: Plasma-Sprayd Ceramic Coating; Corrosion; Oxidation; Defects; Penetrating defect ratio; Microstructural Grading; Sealing Treatment; Low Pressure Plasma-Spray

To utilize superior characteristics of ceramics such as high strength and chemically stable properties, accelerative developments of technologies concerning binding or combining ceramic materials with other various materials are requested. For this meaning, ceramic coating technologies are just now becoming extremely importantTo make clear the performance of plasma-sprayd ceramic coating, evaluations of various degradation characteristics of plasma-splayd ceramic coatings were conducted under corrosion and cyclic heating conditions. Then, to improve resisting characteristics of plasma-sprayd ceramic coating in these environments, sealing treatment, micro-structural grading and control of spraying atmosphere were conducted employing NiCrAlY and ZrO_2 system. Then, several investigations concerning environmental degradation characteristics of these plasma-sprayd coating system, were conducted from various view points. As a result, plasma sprayd zirconia ceramic coating do not have superi … More or resistance especially in 3%NaCl aqueous solution. And, corrosion was especially recognized in the boundary layr between ceramic top coat and undercoated NiCrAlY layrs. Therefore, the corrosion current was generated by electrochemical reactions that was occurred on the surface and in the inner part of NiCrAlY layr under the aqueous environment which was brought about by the penetration of water into interface through defects of ceramic top coat layr. And, it was recognized that micro-structural graded coating shows little improvements in corrosion properties. On the contrary, sealing treatment shows much improvement in corrosion and oxidation characteristics. Then, some evaluations of defect ratio in plasma-spray coating were conducted.Recently, it has been indicated that Low Pressure Plasma Spray (LPPS) coating has higher adhesive strength and minute microstructure. For this reason, LPPS coating has been expected to have better high temperature oxidation resistance compared with Atmospheric Plasma Spray (APS) coating Therefore, in this study, cyclic and continuous heating tests of APS coating and LPPS coating were conducted. The degradation characteristics of these two types of coatings under cyclic heating conditions were investigated. As a result, a few cracks were generated in the top coated ZrO_2-8wt%Y_2O_3 layr of the APS coating after several cycles of heating to 1000ﾟC.Therefore, oxidation of the APS coating has been suppressed. On the contrary, in the case of LPPS coatings many microcracks were generated after several cycles of heating to 1000ﾟC.Oxidation of LPPS coatings preferentially occurred due to oxygen coming into coated layrs through these cracks. The governing factor of microcrack generation in the cyclic heating process was understood from the view point of larger thermal stress generation in the rop coated ZrO_2 -8wt%Y_2O_3 layr in the case of LPPS coating due to having larger Vickers hardness. Therefore, the thermal cycle life was closely correlated to the mechanical properties change due to porosity change. Less

为了利用陶瓷的上级特性，例如高强度和化学稳定性，需要加速发展关于陶瓷材料与其它各种材料的粘合或组合的技术。为了弄清等离子喷涂陶瓷涂层的性能，对等离子喷涂陶瓷涂层在腐蚀和循环加热条件下的各种降解特性进行了研究。然后，采用NiCrAlY和ZrO_2体系对等离子喷涂陶瓷涂层进行封孔处理、组织分级和喷涂气氛控制，以提高涂层在这些环境中的抗腐蚀性能。然后，从不同的角度对这些等离子喷涂涂层系统的环境降解特性进行了研究。因此，等离子喷涂氧化锆陶瓷涂层不具有优异的耐磨性能， ...更多信息 特别是在3%NaCl水溶液中。腐蚀主要发生在陶瓷涂层与NiCrAlY涂层之间的界面层。因此，腐蚀电流的产生是由于水通过陶瓷表面涂层的缺陷渗入界面，在水环境中，NiCrAlY涂层表面和内部发生电化学反应而产生的。而且，人们认识到，微观结构梯度涂层的腐蚀性能的改善不大。相反，封孔处理显示出腐蚀和氧化特性的改善。近年来的研究表明，低压等离子喷涂（LPPS）涂层具有较高的结合强度和细小的组织结构。因此，LPPS涂层有望比大气等离子喷涂（APS）涂层具有更好的高温抗氧化性。因此，在本研究中，对APS涂层和LPPS涂层进行了循环和连续加热试验。研究了这两种涂层在循环加热条件下的降解特性。结果表明，APS涂层的ZrO_2-8wt%Y_2O_3涂层在1000 ℃多次加热循环后，表面产生少量裂纹，从而抑制了APS涂层的氧化。相反，在LPPS涂层的情况下，许多微裂纹产生后，几个循环的加热到1000 ℃。氧化的LPPS涂层优先发生由于氧气进入涂层通过这些裂纹。从ZrO_2 - 8wt%Y_2O_3涂层在LPPS涂层中由于具有较大的维氏硬度而产生较大的热应力的角度，理解了循环加热过程中微裂纹产生的控制因素。因此，热循环寿命与孔隙率变化引起的力学性能变化密切相关。少

项目成果

Hisamichi YAJIMA and Yuji KIMURA: "Degradation Characteristics of Plasma-Spray Ceramic Coatings under Cyclic Heating Conditions" Proc.of Thermal Spraying (ITSC '95) -Current Status and Future Trends-. 621-626 (1995)

Hisamichi YAJIMA 和 Yuji KIMURA：“循环加热条件下等离子喷涂陶瓷涂层的降解特性”Proc.of 热喷涂 (ITSC 95) - 当前状态和未来趋势 -。

木村雄二,吉岡寿扇: "プラズマ溶射コーティングの耐食性に及ぼす封孔処理ならびに組成傾斜化の効果" 材料と環境. Vol.46. 151-157 (1997)

Yuji Kimura、Hisao Yoshioka：“密封处理和成分梯度对等离子喷涂涂层耐腐蚀性的影响”材料与环境，第 46 卷，151-157 (1997)。

H.YAJIMA and Y.KIMURA: "Degradation Characteristics of Plasma-Spray Ceramic Coatings under Cycllc Heating Conditions" Proc.of Thermal Spraying(ITSC '95)-Current Status and Future Trends-. 621-626 (1995)

H.YAJIMA 和 Y.KIMURA：“循环加热条件下等离子喷涂陶瓷涂层的降解特性”Proc.of Thermal Spraying(ITSC 95)-现状和未来趋势-。

Seiji NITTA and Yuji KIMURA: "Evaluation of Defects in Ceramic Coating Films by Various Electrochemical Techniques" Trans.of the Japan Soc.of Mechanical Engineers. 61-589A. 1914-1920 (1995)

Seiji NITTA 和 Yuji KIMURA：“通过各种电化学技术评估陶瓷涂层膜的缺陷”Trans.of the Japan Soc.of Mechanical Engineers。

新田誠司、木村雄二: "各種の電気化学的手法によるセラミックコーティング膜の欠陥評価" 日本機械学会論文集、A編. Vol.61. 1914-1920 (1995)

Seiji Nitta、Yuji Kimura：“使用各种电化学方法评估陶瓷涂层膜”，日本机械工程师学会会刊，A 版。1914-1920 年（1995 年）。