热喷涂制备耐磨涂层的研究进展

综述了不同热喷涂技术的原理和特点,包括大气等离子喷涂、超音速等离子喷涂、超音速空气燃料喷涂、爆炸喷涂、超低压等离子喷涂、悬浮液等离子喷涂、高速电弧喷涂等.分析了不同热喷涂技术制备的耐磨涂层的国内外研究现状,以及不同材料体系的减摩耐磨涂层的特点及其所适应的最佳热喷涂技术.对未来热喷涂技术制备耐磨涂层的研究方向提出展望.     

等离子喷涂技术研究现状

概述了等离子喷涂的基本原理,并介绍了大气等离子喷涂、超音速等离子喷涂和低压等离子喷涂3种常用的等离子喷涂技术。综述了该技术在制备保护性涂层、功能性涂层以及零件修复强化方面的应用,展望了等离子喷涂技术未来的发展趋势。     

等离子喷涂陶瓷涂层的现状与应用

本文综述了陶瓷涂层的等离子喷涂制备方法、工艺特点以及陶瓷涂层在各领域中的应用,介绍了目前常用的等离子喷涂陶瓷材料,并对等离子喷涂陶瓷涂层的发展趋势进行了展望.     

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。     

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.     

超音速等离子喷涂制备Cr_2O_3涂层的显微组织及抗热震性能(英文)

为了研制一种新型连铸结晶器材料,采用高效能超音速等离子喷涂技术在纯铜基体上制备了Cr2O3陶瓷涂层。使用X射线衍射、扫描电子显微镜、图形软件、彩色3D激光显微镜和显微硬度计对涂层进行了表征及分析,分别在450℃和600℃对涂层进行了热震试验。结果表明,涂层继承了起始粉末的物相,但是Cr2O3的结晶度有所差异;陶瓷涂层表面为良好熔化区和部分熔融颗粒组成的双态组织,涂层断口形貌为典型的片层状组织,涂层截面可见均匀分布的富铬带。涂层孔隙率为1.2%,表面粗糙度为4.763μm,Vickers显微硬度为1 628 MPa。试样在450℃和600℃分别经历了均值为127.4和58.6次热震循环后,其半球顶端出现大面积剥落,但圆柱主体部分完好,表明Cr2O3陶瓷涂层具备良好的抗热疲劳性能,超音速等离子喷涂适合于结晶器铜板表面涂层的制备。     

Microstructure and Thermal Shock Resistance of Cr2O3 Ceramic Coatings Deposited by Supersonic Atmosphere Plasma Spraying

为了研制一种新型连铸结晶器材料,采用高效能超音速等离子喷涂技术在纯铜基体上制备了 Cr2O3陶瓷涂层。使用 X 射线衍射、扫描电子显微镜、图形软件、彩色 3D 激光显微镜和显微硬度计对涂层进行了表征及分析,分别在 450 ℃和 600 ℃对涂层进行了热震试验。结果表明,涂层继承了起始粉末的物相,但是 Cr2O3的结晶度有所差异;陶瓷涂层表面为良好熔化区和部分熔融颗粒组成的双态组织,涂层断口形貌为典型的片层状组织,涂层截面可见均匀分布的富铬带。涂层孔隙率为 1.2%,表面粗糙度为 4.763 μm,Vickers 显微硬度为 1 628 MPa。试样在 450 ℃和 600 ℃分别经历了均值为 127.4 和 58.6 次热震循环后,其半球顶端出现大面积剥落,但圆柱主体部分完好,表明 Cr2O3陶瓷涂层具备良好的抗热疲劳性能,超音速等离子喷涂适合于结晶器铜板表面涂层的制备。     

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。     

SiC复合陶瓷涂层的制备与实验研究

本文利用等离子喷涂技术制备SiC复合涂层。SiC是一种超硬材料,同时是一种耐高温材料,其具有优良的抗氧化和抗热震性能,但由于SiC没有物理熔点,2545℃分解,采用喷涂的方法不易制备优良的涂层。本文采用添加金属、陶瓷等助剂,用等离子喷涂的方法制备SiC-Y_2O_3-AI_2O_3复合涂层和SiC-FeAl复合涂层,通过XRD对其成分结构进行检测。结果表明SiC成功进入涂层内部,所得到的涂层中SiC-FeAl复合涂层具有非常好的抗热震性能。SiC-Y_2O_3-Al_2O_3复合陶瓷涂层抗高温热震性比较好,硬度和耐磨性很高。     

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。     

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.     

Comparative study of the corrosion resistance of thermally sprayed ceramic coatings and their bulk ceramic counterparts

A comparative study of the corrosion properties of thermally sprayed ceramic coatings (Al₂O₃, Al₂O₃–TiO₂ with different ratios, mullite, and ZrSiO₄) and their sintered bulk ceramic counterparts was performed. The coatings were deposited on corrosion-resistant steel substrates using atmospheric plasma spraying (APS) and high velocity oxy-fuel (HVOF) spraying processes. The corrosion properties were investigated in 1 N solutions of NaOH and H₂SO₄ at 85 °C, respectively. The coating microstructures and phase compositions, as well as the corrosive environment were shown to have a strong effect on the corrosion resistance of the coatings. Al₂O₃–coatings were more sensitive to these factors than Al₂O₃–TiO₂ coatings were.The corrosion resistance of the bulk ceramics was superior to that of the thermally sprayed coatings. This is mainly because the coatings exhibited specific microstructure and contained amorphous and/or metastable phases not appearing in the bulk ceramics.     

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.     

Phase transition and interface evolution of Al2O3/ZrO2 particles in plasma-sprayed coatings

Alumina and zirconia ceramic particles exhibit high hardness and excellent wear resistance at high temperature, and hence are used as ceramic reinforcement phases in some plasma sprayed coatings. In this study, the interface evolution of a zirconia/alumina eutectic ceramic and the phase transition of zirconia in a plasma-sprayed coating were investigated. Scanning electron microscopy and transmission electron microscopy combined with focused-ion beam and energy dispersive X-ray were used to analyze the microstructure and composition of the ceramic interface. The results showed that the eutectic ceramic particles consisted of alumina (outer) and columnar zirconia (inner) before and after the plasma spraying process. The inner zirconia part showed the martensitic transformation of t-type zirconia to stripe-like m-type zirconia. After the plasma spraying, the interface between alumina and zirconia changed significantly, which formed a new oxide layer. The phase transition mechanism in the ceramic particle and oxide layer formation mechanism at the alumina/zirconia interface were investigated.     

Deposition and ablation resistance of HfC-based coatings prepared on SiC-coated C/C composites by supersonic atmospheric plasma spraying

In order to improve the ablation properties of C/C composites, HfC-based coatings with different mass ratios of SiC were deposited on the surface of SiC-coated carbon/carbon composites by supersonic atmospheric plasma spraying. The morphologies and microstructures of the HfC-based coatings were characterised. The ablation resistance test was carried out by oxyacetylene torch. The results show that the as-prepared coatings are multiphase coatings consisting of HfC, HfO₂, SiC and SiO₂. The structure of different coatings is dense. After ablation for 60?s, the ablation centre region of coating is smooth without obvious microcrack and pinhole, and no interlaminar crack can be observed at the cross-section. An Hf–Si–O compound oxide layer is generated on the surface of coating, which is beneficial for protecting the C/C composites from being ablated. Meanwhile, the further generated HfSiO₄ can play a pinning effect, which can prevent crack extension.     

Structure-property relationship and design of plasma-sprayed La2Ce2O7/8YSZ composite coatings for gas turbine blades

Novel lanthanum-cerium oxide/8?wt% yttria partially stabilized zirconia (LC/8YSZ) thermal barrier coatings (TBCs) were deposited by supersonic atmospheric plasma spraying. The thermal insulation temperature and thermal shock resistance of LC/8YSZ double-ceramic-layer TBCs (DCL-TBCs) were quantitatively evaluated by a burner rig test. The results showed that the thermal insulation temperature increased with the increase of LC layer thickness in DCL-TBCs. When the thickness ratio between LC layer and 8YSZ layer was close to 1:1, the DCL-TBCs had the highest thermal shock resistance. LC/8YSZ thickness ratio significantly affected the energy release rate and the stress induced by thermal gradient or sintering. The sintering stress was found to be the main reason that caused the delamination of LC layer, however, the stress induced by thermal gradient resulted in the spallation of YSZ layer.     

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。     

耐温耐磨双组分瓷膜涂料的研制

瓷膜涂料具有高硬度、耐磨、耐腐蚀等优异特性,以甲乙两组分按一定比例混合熟化8。24h后,喷涂至工件上,于180℃烘烤20-40min,制得瓷膜涂层。研究了甲、乙组分配比,以及纳米氧化铝和碳化硅用量对涂膜综合性能的影响。通过在烫发器上的应用,进一步表明瓷膜涂料具有优异的耐温和耐磨特性。