间断接触式等离子体放电沉积金属陶瓷层

存大量科学试验基础上，提出一种金属表面形成金属陶瓷涂层的新工艺方法。该方法具有放电电压低、陶瓷层结构致密、与基体冶金结合、适用于多种金属材料等优点。文中还对某条件下利用该方法形成的陶瓷层进行了初步分析。     

多尺度WC-Co金属陶瓷涂层的研究现状

W C基金属陶瓷是应用广泛的耐磨材料,具有低孔隙率、高硬度、出色的耐磨性和抗氧化性的特性。介绍了多尺度对WC-Co涂层的组织与性能的影响。综述了采用不同方法制备的多尺度WC-Co金属陶瓷耐磨涂层的研究进展。提出了热喷涂多尺度WC-Co金属陶瓷耐磨涂层未来的发展趋势。     

超音速火焰喷涂WC金属陶瓷涂层性能研究进展

WC金属陶瓷涂层因具有优良的耐磨损和耐腐蚀性等性能而在煤化工、石油化工、航空航天等领域得到了应用。针对超音速火焰喷涂技术在常用钢铁材料基体上制备的WC金属陶瓷涂层,介绍了WC金属陶瓷涂层中粉末粒径、元素含量、涂层的厚度与喷涂角度对涂层组织和性能的影响。从涂层耐腐蚀性、耐磨损性、显微硬度、结合强度以及孔隙率等方面,对涂层性能的相关研究进展进行了总结和分析。最后,提出了WC金属陶瓷相关研究中存在的问题及未来提升WC金属陶瓷性能的研究方向。     

等离子喷涂制备Co基TiC金属陶瓷涂层的微观形貌及耐高温腐蚀性能

采用等离子喷涂技术在GH586合金表面制备了一层Co基TiC金属陶瓷涂层。研究了TiC含量对Co基TiC金属陶瓷涂层显微组织及耐高温腐蚀性能的影响。结果表明:TiC陶瓷颗粒与Co基粉体有良好的润湿性,呈现相互包裹的结构,涂层结合紧密无缺陷;TiC的加入,提高了Co基TiC金属陶瓷涂层的耐磨性,但当TiC含量过高时,团聚现象严重,导致涂层的耐高温腐蚀性能降低;TiC质量分数为10%时,TiC颗粒在涂层中分布较为均匀,此时涂层的耐高温腐蚀性能和耐磨性都较优。     

金属表面陶瓷涂层的技术特点及应用

对各种金属表面陶瓷涂层技术的主要内容、发展概况和技术特点进行了综述,并展望了金属陶瓷涂层技术发展趋势。     

反应火焰喷涂三元硼化物金属陶瓷涂层的组织和性能

反应喷涂是近年来发展的一种制备陶瓷/金属复合涂层的新技术,它是将自蔓延高温合成与普通的热喷涂技术相结合,在合成材料的同时使合成材料沉积,陶瓷相为原位合成,晶粒细小,与金属基体之间结合良好.采用反应火焰喷涂方法在45钢表面制备Mo2FeB2三元硼化物金属陶瓷涂层,分析了粉末团聚方式对涂层显微组织的影响,测试了涂层的显微硬度及耐磨性能.结果表明:团聚粉末经过火焰喷涂获得Mo2FeB2三元硼化物金属陶瓷涂层,其显微硬度达到1 200HV0.1,具有良好的耐磨性能.     

金属陶瓷切削刀具的耐磨涂层

沉积耐磨涂层的常规化学气相沉积和物理气相沉积方法已被证明不能有效地提高以Ｎｉ￣Ｍｏ基粘结剂粘结的ＴｉＣ基或ＴｉＣＮ基金属陶瓷的使用寿命，因为粘结剂与涂层之间会发生强烈的反应。现已开发了一种金属陶瓷切削刀具沉积碳化铬基多层涂层的新方法。这种方法包括真空处理 基体和沉积由碳化铬上层和碳化物层和基体之间Ｎｉ基中间层组成的涂层。经涂层的金属陶瓷可转位刀片的耐磨性由于涂层的独特结构及其优异性能而得到明显提高     

等离子喷涂金属-陶瓷阶梯涂层

描述了阶梯涂层的等离子喷涂并利用简单的物理模型分析了阶梯涂层中间过渡区的金属一陶瓷界面，特别值得一提的是，确立了主要的控制沉积参数、粉末特性和选粉装置等在阶梯涂层中所起的重要作用．后者控制了金属一陶瓷阶梯涂层中的过渡区的结枸组成。在对遗些参数的有关知识进行了一定的了解的基础上．对基体的同一区域金属和陶瓷粉粒瞬时沉积的均匀性特征，推导出了一十新颖的计算公式。此外，描述了阶梯区金属一陶瓷界面非常重要的局部规整关系。各种结构分析技术和简单的热力学计算能够对金属和陶瓷组分之间的站台给出新的解释．预测的金属陶瓷阶梯涂层的结台强度比用金属作打底层的陶瓷涂层的结合强度迁高．用NiCr-Zr02(Mg0)阶梯涂层的实例对结果进行了说明。     

WC/FeAl金属间化合物基金属陶瓷涂层的冷喷涂制备

采用WC/Fe/Al混合粉末,通过机械合金化制备40v0l％ WC/Fe(Al)固溶体复合粉末,利用冷喷涂沉积涂层并结合热处理原位反应制备了WC/FeAl金属间化合物基金属陶瓷涂层.研究了球磨时间对复合粉末相结构、晶粒尺寸及组织结构的影响,并分析了冷喷涂WC/FeAl金属间化合物基金属陶瓷涂层的组织和显微硬度.结果表明,机械合金化可获得WC陶瓷颗粒呈微/纳米多尺度分布的WC/Fe(Al)金属陶瓷复合粉末,球磨36 h的复合粉末基体相平均晶粒尺寸约为90 nm,冷喷复合涂层组织致密、多尺度WC颗粒在基体中均匀弥散分布,涂层显微硬度约为1060 HV0.3,涂层在650℃热处理后发生Fe(Al)固溶体向FeAl金属间化合物的原位转变,制备出了WC/FeAl金属间化合物基金属陶瓷涂层.     

锅炉“四管”用耐磨耐蚀涂层研究进展

总结了锅炉"四管"失效的形式和机理.热腐蚀和高温冲蚀磨损是锅炉"四管"失效的主要原因,采用热喷涂金属涂层、陶瓷涂层及金属陶瓷复合涂层等可以有效控制热腐蚀和高温冲蚀磨损.目前制备高性能涂层常用的方法有等离子喷涂、电弧喷涂、超音速火焰喷涂等.详细介绍了高镍铬合金涂层的研究状况和喷涂工艺的特点,最后展望了纳米结构涂层在该领域的研究进展和应用前景.     

Difference in particle characteristics and coating properties between spraying metallic and ceramic powder cored wires

The sprayed particles of metallic and cermet wires were collected to analyze the atomization state of the particles in arc spraying forming, the microstructure and properties of metallic and ceramic coatings were investigated and compared. Particle size analyzer was used for quantifying particle size. The XRD, SEM and optical microscope（OM） were used to analyze the phase composition and microstructure of the particles and coatings. From the experimental results, some difference of particle characteristics was established between the spraying metallic and ceramic cored wires, and the microstructure and properties of coatings depend strongly on the particles behaviors. The result shows that Fe-TiB2/Al2O3 composite coating has a high potential for abrasive wear applications.     

TiB2陶瓷颗粒增强的金属基复合涂层

采用电弧喷涂制备TiB2陶瓷颗粒增强的NiCr-TiB2,NiCr-TiB2/Al2O3和304L-TiB2及304L-TiB2/Al2O3四种金属基复合涂层.采用光学显微镜、扫描电子显微镜(SEM)结合透射电子显微镜(TEM)观察和详细分析了TiB2陶瓷颗粒增强复合涂层的显微组织及微观结构,探讨涂层的形成机理.结果表...     

镁合金表面冷喷涂层防护研究进展

镁合金作为最轻质的金属结构材料,由于其密度低和比强度高等优良的物理和力学性能,在航空、航天、汽车以及电子等领域引起广泛关注。然而,镁合金化学性质活泼、耐腐蚀和耐磨损性差等缺点严重制约其进一步应用。近些年发展起来的冷喷涂技术,在固态下制备涂层,涂层致密且与基体结合良好,因此可为镁合金表面防护提供一种新的有效方法。主要综述了镁合金表面冷喷涂耐腐蚀涂层(纯铝、铝合金和复合材料涂层)和耐磨损涂层(合金和复合材料涂层),论述了影响冷喷涂层耐腐蚀、耐磨损以及其他力学性能(硬度和涂层/基体结合强度)的主要因素,包括杂质元素含量、合金种类以及复合材料涂层中陶瓷颗粒含量、尺寸和形貌等。对比了几种常用表面处理技术制备的纯铝涂层的耐腐蚀性能,并阐述了冷喷涂技术在镁合金表面防护方面的优势。此外,还分析了热处理对冷喷涂纯铝和复合材料涂层耐蚀性的影响。最后提出了目前冷喷涂技术在镁合金防护方面的局限性以及发展难题,对未来研究趋势进行了展望。     

高熵陶瓷薄膜和涂层的研究进展

具有5种或5种以上阳离子的高熵陶瓷由于其在各种结构和功能应用中的优异性能,引起了人们的极大关注。在引入熵稳定概念后,人们开始做出重大努力来增加熵,使吉布斯自由能最小化,并实现稳定的单相高熵陶瓷。本文综述了近年来高熵陶瓷薄膜和涂层的最新研究进展。首先从高熵陶瓷薄膜和涂层中的高熵概念出发,介绍了其微观结构;然后概述了高熵陶瓷薄膜和涂层的制备方法,并详细总结了其优异性能的研究成果;最后在此基础上对高熵陶瓷薄膜和涂层进行展望。     

Alumina coatings obtained by thermal spraying and plasma anodising — A comparison

Thermally sprayed alumina coatings are widely used in a range of industrial applications to improve wear and erosion resistance, corrosion protection and thermal insulation of metallic surfaces. These properties are required for many components to be used for production processes in the paper and printing industry.Another appropriate method to produce ceramic coatings is the plasma electrolytic oxidation (PEO). However PEO can only be applied on self-passivating metals like aluminium, titanium, magnesium and their alloys. The present paper concerns a combination of cost-efficient arc spraying and flame spraying of Al coatings (Al99.5, AlCu4Mg1) on steel substrates and post-treatment by plasma-electrolytic oxidation (PEO). The microstructure and phase composition of generated oxide coatings are examined and discussed. The created Al₂O₃ layers show outstanding hardness up to 1600 HV0.1, good bonding strength and excellent abrasion resistance compared to atmospheric plasma-sprayed Al₂O₃-coatings. The results show the superior performance of PEO-coatings and demonstrate their applicability for technical components in extreme operating conditions.     

Mechanical property of Fe-base metallic glass coating formed by gas tunnel type plasma spraying

Metallic glass has excellent functions such as high toughness and corrosion resistance. Therefore it is one of the most attractive materials, and many researchers have conducted various developmental research works. However, the metallic glass material is expensive and a composite material is preferred for the industrial application. Thermal spraying method is one of potential candidates to produce metallic glass composites. The gas tunnel type plasma system, which has high energy density and efficiency, is useful for smart plasma processing to obtain high quality ceramic coatings such as alumina (Al₂O₃) and zirconia (ZrO₂) coatings. Also, the gas tunnel type plasma spraying can produce metallic glass coatings. In this study, the Fe-base metallic glass coatings were formed on the stainless-steel substrate by the gas tunnel type plasma spraying, and the microstructure and mechanical property were investigated. The Fe-base metallic glass coatings of about 200 μm in thickness were dense with a Vickers hardness of about Hv = 1100 at plasma current of 300 A. The abrasive wear resistance of Fe-base metallic glass coating was higher than the SUS substrate.     

Essential Factors Influencing the Bonding Strength of Cold-Sprayed Aluminum Coatings on Ceramic Substrates

The present work summarizes the most important results of a research project dealing with the comprehensive investigation of the bonding mechanisms between cold-sprayed Al coatings and various poly- and monocrystalline ceramic substrates (Al₂O₃, AlN, Si₃N₄, SiC, MgF₂). Due to their exceptional combination of properties, metallized ceramics are gaining more and more importance for a wide variety of applications, especially in electronic engineering. Cold spray provides a quick, flexible, and cost-effective one-step process to apply metallic coatings on ceramic surfaces. However, since most of the existing cold-spray-related publications focus on metallic substrates, only very little is known about the bonding mechanisms acting between cold-sprayed metals and ceramic substrates. In this paper, the essential factors influencing the bonding strength in such composites are identified. Besides mechanical tensile strength testing, a thorough analysis of the coatings and especially the metal/ceramic interfaces was conducted by means of HRTEM, FFT, STEM, EDX, EELS, GAXRD, and EBSD. The influence of substrate material, substrate temperature, and particle size is evaluated. The results suggest that, apart from mechanical interlocking, the adhesion of cold-sprayed metallic coatings on ceramics is based on a complex interplay of different mechanisms such as quasiadiabatic shearing, static recrystallization, and heteroepitaxial growth.     

料浆法Si0，基陶瓷涂层制备及性能研究

为了提高1Cr18Ni9钢基体的耐蚀性和耐磨性,扩大其在工业中的应用范围,采用料浆法在不锈钢基体上制备具有保护性的SiO2基陶瓷涂层.并对涂层进行相结构及显微组织分析,结果表明:涂层与基体结合良好,且涂层中有新相生成.腐蚀试验和磨损试验证明,采用本工艺在1Cr18Ni9钢表面涂覆陶瓷层能大幅度提高基体的耐蚀性和耐磨性,对生产实践有一定的指导意义.     

Oxidation Behavior of a High-Nb-Containing TiAl Alloy with Multilayered Thermal Barrier Coatings

Oxidation of TiAl alloys has been recognized as an obstacle for high-temperature applications such as aero engine and gas turbine. Substantial efforts have been made to improve oxidation resistance of TiAl alloys at elevated temperatures. In this study, multilayered thermal barrier coatings are prepared to protect a high-Nb-containing TiAl alloy from oxidation by air plasma spraying. The combination of Al₂O₃-13wt.%TiO₂ ceramic coatings and NiCoCrAlY metallic coatings can improve thermal stability and increase the service lifetime of coatings. The fully melted TiO₂ particles distribute in ceramic coatings uniformly and act as sealing pores and microcracks, which decrease porosity of the ceramic coatings and reduce diffusion channels of oxygen atoms. The porosity of surface and cross-section morphology are 5.5?±?0.8 and 5.1?±?0.8%, respectively. The results of oxidation experiment carried out at 800 and 900 °C for 100 h indicate that the coatings can effectively protect a high-Nb-containing TiAl alloy from oxidation. The mass gain of the high-Nb-containing TiAl alloys with coatings is lower than that of the one without coatings. The ceramic coatings retard diffusion of large amount of oxygen atoms, and bond coatings avoid to be excessively oxidized. Thus, the multilayered thermal barrier coatings exhibit an excellent long-term stability.