等离子喷涂陶瓷涂层的界面研究

介绍了等离子喷涂陶瓷涂层的界面特征,综述了等离子喷涂涂层的界面物理化学特性,在此基础上总结提出涂层界面设计与控制的几个先进途径,并探讨了等离子喷涂陶瓷涂层的界面研究的重点与难点问题.     

等离子喷涂陶瓷涂层降低孔隙率的研究进展

通过对等离子喷涂陶瓷涂层降低孔隙率研究现状的文献综述,概括了国内外在等离子喷涂制备Al2O3及其复合涂层、Cr2O3及其复合涂层、ZrO2及其复合涂层降低孔隙率的研究进展,展望今后等离子喷涂陶瓷涂层降低孔隙率的发展方向.     

激光重熔处理等离子喷涂陶瓷涂层的研究现状及展望

本文介绍了激光重熔等离子喷涂陶瓷涂层的研究进展,并对其进行了展望。激光重熔使等离子喷涂涂层致密性提高,涂层与基体的结合方式由机械结合为主改为冶金结合为主,层状组织变化为柱状组织;激光重熔使等离子喷涂涂层的热疲劳抗力、耐蚀性、耐磨性、抗高温氧化性等性能提高。指出了激光重熔等离子喷涂陶瓷涂层目前存在的问题,探讨了激光重熔等离子喷涂陶瓷涂层易产生裂纹,甚至发生涂层剥落等问题的原因,提出了激光重熔技术的研究方向。     

等离子喷涂陶瓷涂层综述

本文综述了利用等离子技术喷涂高性能陶瓷涂层的技术特点和应用情况以及几种热点陶瓷涂层的特性,指出了等离子技术喷涂陶瓷涂层中存在的问题,分析了可行的解决方法。     

超音速等离子喷涂制备陶瓷涂层的研究进展

超音速等离子喷涂技术由于具有高温、高速的独特优点,且制备的陶瓷涂层结合强度和致密度高,孔隙率低,具有优良的耐磨损、耐腐蚀、抗氧化和热冲击性能,已成为一些发达国家竞相研究的热点.本文介绍了常用的陶瓷涂层材料,综述了超音速等离子喷涂技术及其制备陶瓷涂层的工艺特点,并对超音速等离子喷涂制备高性能陶瓷涂层的发展趋势进行了展望.     

等离子喷涂Al2O3陶瓷涂层的研究

研究等离子喷涂Al2O3陶瓷涂层的抗热震性能,分析并计算等离子喷涂Al2O3陶瓷涂层和AlAl2O3涂层中的残余应力,得出了两种涂层的应力分布,测试了TiO2含量对Al2O3陶瓷涂层性能的影响,检验了影响涂层质量的工艺参数.     

等离子喷涂承烧板涂层寿命的研究

等离子喷涂承烧板是一种用于MLCC等陶瓷电子元器件煅烧的一种新型结构陶瓷耐火材料,这种窑具最重要的质量指标之一是使用寿命,在多种场合下涂层寿命对这种窑具的使用寿命有着决定性影响。本文模拟客户使用条件,采用等离子喷涂方法制备涂层,对比了不同的部分稳定氧化锆材料(PSZ)喷涂粉作为等离子喷涂承烧板喷涂层时使用寿命的差别,从而得出适合使用于等离子喷涂承烧板的部分稳定氧化锆喷涂粉。     

热喷涂技术制备陶瓷涂层的研究进展

介绍了常用的热喷涂材料,综述了电弧喷涂、火焰喷涂和等离子喷涂3种制备陶瓷涂层的热喷涂技术的基本原理,展望了热喷涂技术制备陶瓷涂层的发展趋势和应用前景。     

陶瓷热喷涂

本文简述了陶瓷材料热喷涂的几种方法,棒材火焰喷涂法,粉末火焰喷涂法及等离子弧喷涂法,并对陶瓷涂层及陶瓷－金属复合涂层进行了简介。     

耐液锌腐蚀材料的研究

实现热镀锌内加热技术的关键是解决耐锌蚀材料的问题。本文分析了当前解决液锌腐蚀的不同方法。研究了等离子喷涂耐液锌腐蚀陶瓷涂层,提出了等离子喷涂耐液锌腐蚀陶瓷涂层的设计方案。     

Grinding of hard and brittle ceramic coatings: Force analysis

In this work, a grinding force model has been proposed and a correlation between the analytical model and the experimental grinding forces obtained during finishing of plasma sprayed ceramic coatings has been investigated. Thermally sprayed ceramic coatings have low fracture toughness and develop micro brittle fracture under moderate mechanical loading. In this investigation, grinding of air plasma sprayed alumina, zirconia, and titania coatings were studied theoretically and experimentally. It was observed that the ground surface contained micro-cracks and debris of irregular fragmented chips owing to the micro-brittle fracture. A grinding force model is proposed to incorporate the fracture behavior of the ceramic coating. This was substantiated through experimental values showing low grinding forces.     

Thermal spraying of ceramics

In the last few years, the number of publications dealing with ceramic coatings has increased very rapidly. To present an overview of this field, a bibliografic review of the thermal sprayed ceramics is performed. Investigated and studied successively are the thermal spraying techniques (flame, plasma and detonation), the sprayed ceramics and the applications of these coatings. It appears that plasma spraying is the most common technique, that ceramic coatings are most often made of the metal oxides and their main application is for wear resistance.     

陶瓷涂层热喷涂制备工艺

热喷涂陶瓷涂层将陶瓷材料耐高温、耐磨、耐腐蚀及隔热、绝缘等性能与金属材料的特点有机地结合起来。本文介绍了陶瓷涂层的热喷涂方法及工艺。     

Al2O3-CoCrAlY 复合陶瓷激光熔覆层的组织与性能

研究了Ａｌ２Ｏ３－ＣｏＣｒＡｌＹ复合陶瓷涂层的组织结构、成分分布及其耐磨性能。结果表明：等离子喷涂层的组织呈层片状,面层由α－Ａｌ２Ｏ３和少量的γ－Ａｌ２Ｏ３组成,层间为机械结合界面,涂层平均硬度为８９７ＨＶ０．２。经激光重熔后的组织为单一的α－Ａｌ２Ｏ３柱状晶,在ＣｏＣｒＡｌＹ与基体间有界面相形成,其界面为冶金结合,层间存在着平缓的成分过渡;Ａｌ２Ｏ３与ＣｏＣｒＡｌＹ间的界面结合状况得到了明显的     

等离子喷涂陶瓷涂层在内燃机上的应用研究

特种陶瓷材料由于具有良好的综合性能,近几年在动力工程和先进发动机上的应用愈来愈广,陶瓷与金属的连接工艺成为材料工程领域的热点研究课题。等离子喷涂是目前国内外最常用的金属表面陶瓷涂层技术。为此,对等离子喷涂陶瓷涂层在内燃机上的应用进行了研究,分析了等离子喷涂过程中存在的主要问题,提出了这些问题的解决途径,并展望了该项技术的应用前景。     

Laser surface modification of plasma sprayed CYSZ thermal barrier coatings

In this study, Inconel 738 LC superalloy coupons were first sprayed with a NiCoCrAlY bond coat and then with a ceria and yttria stabilized zirconia (CYSZ) top coat by air plasma spraying (APS). After that, the plasma sprayed CYSZ thermal barrier coatings (TBCs) were treated using a Nd:YAG pulsed laser. The effect of laser glazing on the microstructure of the coatings was investigated. The microstructures and surface topographies of both as-sprayed and laser glazed samples were investigated using field emission scanning electron microscope (FESEM) and atomic force microscope (AFM). The phases of the coatings were analyzed with X-ray diffractometry (XRD). The microstructural analysis results revealed that laser surface glazing of ceramic top coat reduced the surface roughness considerably, eliminated the surface porosities and produced a network of continuous cracks perpendicular to the surface. XRD patterns also showed that both as-sprayed and laser glazed top coats consisted of nonequibrium tetragonal (T′) phase.     

Engineered Multilayer Thermal Barrier Coatings for Enhanced Durability and Functional Performance

The durability of plasma sprayed thermal barrier coatings (TBCs) has been of significant interest ever since their introduction in gas turbine engine components. Of particular importance is the role of coating processing, microstructure and ensuing properties on their thermal cycle life. Among the coating properties of the ceramic top coat that have shown strong correlations with durability include the elastic modulus (i.e., compliance) and the fracture toughness, both of which are influenced by processing as well as thermal aging during service. In this article, we have systematically investigated furnace cycle durability of plasma sprayed TBCs produced from controlled processing conditions, yielding differences in both modulus and toughness. Following performance assessment and mechanistic insights obtained from single layer ceramic coatings, novel bilayer architectures have been proposed and fabricated, in an effort to improve furnace cycle durability. The bilayer approach targets coating properties based on location, by providing dense, high toughness coating at regions prone to delamination failure (near‐interface), while allowing for the majority of the coating to contain high porosity, resulting in reduced overall modulus. Such improved bilayers simultaneously display both high durability and low thermal conductivity enabling a promising approach for functionally optimized coatings. The plasma spray process together with its ability to dynamically change process parameters enables the fabrication of these novel architectures.     

不同基体条件下Sm_2Zr_2O_7/YSZ热障涂层的残余应力

采用有限元法研究了基体条件对等离子喷涂Sm2Zr2O7/YSZ双陶瓷层热障涂层涂层的残余热应力,并与单一Sm2Zr2O7涂层进行了比较。计算结果表明,涂层的残余热应力随金属基体的热膨胀系数增加而增大,当基体厚度超过25mm后,径向应力不再变化,基体半径对涂层残余应力的影响可以忽略。Sm2Zr2O7/YSZ涂层的热应力明显小于单一的Sm2Zr2O7涂层,增加涂层的层数可缓解残余热应力。     

Challenging zircon coatings by suspension plasma spraying

Zircon is a ceramic material that decomposes at high temperature, limiting its use by conventional thermal spraying. In this work, it is intended to use thermal spraying from concentrated aqueous suspensions to evaluate the possibility of obtaining coatings in which a significant proportion of zircon could be preserved. For this purpose, stable concentrated suspensions of zircon have been prepared, which have been subsequently sprayed at two different spraying distances. The coatings were characterised in terms of microstructural features and the amount of zircon present in the coatings was quantified. All the coatings obtained display the typical microstructure derived from the deposition of liquid feedstocks by plasma spraying. In all cases, the XRD analysis demonstrates the partial decomposition of zircon into zirconia and residual silica, but also that a significant percentage (about 20%) is preserved without decomposing, which marks a strong difference with respect to reported data for atmospheric plasma spraying.