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超音速等离子喷涂工艺对纳米Al_2O_3-13%TiO_2涂层的影响 总被引:1,自引:0,他引:1
采用四因素三水平正交试验,通过显微硬度和孔隙率两项指标的评估,对超音速等离子喷涂电流、电压、Ar气流量和喷涂距离4个工艺参数进行了优化设计。结果表明,4个因素对纳米Al2O3-13%TiO2涂层综合性能的影响主次顺序是:喷涂电压、Ar气流量、喷涂距离、喷涂电流,并最终确定了最优的喷涂参数。利用XRD、SEM等手段分析了纳米Al2O3-13%TiO2复合粉末和涂层的相结构和微观结构,采用显微硬度计和图像处理方法测定了涂层的显微硬度和孔隙率。最优工艺参数制备的涂层显微硬度值1208 HV,孔隙率为2.26%,拉伸法测定其结合强度为48 MPa。 相似文献
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用等离子喷涂工艺在Q235钢基体上制备Cr2O3陶瓷涂层,并采用磷酸铝和环氧树脂对其进行封孔处理。利用图像分析法和电化学方法对封孔前后涂层的孔隙率进行了测试,采用弱极化技术和电化学阻抗谱技术对封孔前后涂层的耐蚀性能进行了研究。结果表明,封孔处理提高了涂层的耐蚀性能,环氧树脂封孔涂层的耐蚀性能更优异;陶瓷涂层在腐蚀介质中耐蚀性能主要取决于涂层的孔隙率。 相似文献
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目的提高涂层的结合强度和改善微观组织结构。方法选取WC-10Co4Cr喷涂材料,分别通过激光等离子复合热源喷涂工艺以及等离子喷涂工艺制备涂层,对涂层组织与基本性能进行检测,对两种不同喷涂工艺的沉积机理作对比分析研究。研究复合热源喷涂涂层微观组织结构以及涂层与基体间结合方式较等离子喷涂涂层的变化。利用高速摄像仪对激光等离子复合热源喷涂以及等离子喷涂的工艺过程进行跟踪监测和分析,研究复合热源沉积过程中,基体表面微熔池的形成及粉末粒子在不同沉积工艺过程中熔融状态的对比,分析等离子喷涂涂层和复合热源喷涂涂层的沉积机理。结果等离子喷涂WC-10Co4Cr涂层以机械结合方式为主,涂层结合强度为39.5 MPa,孔隙率为1.7%,而激光等离子复合热源喷涂WC-10Co4Cr涂层实现了冶金结合,其结合强度提升到91 MPa,孔隙率降低到0.86%。结论激光等离子复合热源喷涂工艺可以有效提升涂层的结合力,改善涂层组织致密性,更有利于涂层的耐磨耐腐蚀性能。 相似文献
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通过对等离子喷涂涂层在Nd-YAG处理有产处理后的摩损量对比,研究了激光处理对等离子喷涂Cr2O3陶瓷薄涂层的影响。为此,用陶瓷/SAE4620铜以线接触配对进行了不形试样磨损试验。还讨论了磨损机理和因激光处理引起的涂层中有关孔隙率、显微结构和涂层结合情况的变化。 相似文献
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用5kW CO2激光器对铜排表面的Cr等离子喷涂层进行重熔,并对激光熔覆层组织、硬度、导电性能进行了研究。结果表明,激光熔覆层的组织致密、均匀,与基体结合很好。涂层平均显微硬度为HV200,是基体的3倍左右。激光熔覆层和等离子喷涂层在0.35mm处的电导率分别为70.4%IACS和53,5%IACS.对于3mm厚的铜排,激光熔覆和等离子喷涂铜排的整体电导率则分别为96.2%IACS和92.6%IACS。激光熔覆层和激光熔覆后铜排的整体电导率均高于相应的等离子喷涂层及其铜排。 相似文献
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等离子喷涂人工骨涂层材料 总被引:9,自引:0,他引:9
等离子喷涂是一种常用的生物医用材料表面改性技术,被广泛应用于钛等金属人工骨的表面改性.为了满足人工骨涂层的临床应用需要,近年来发展了一些新的涂层材料和后处理工艺技术.利用火焰蒸汽处理技术对等离子喷涂羟基磷灰石涂层进行后处理,提高了涂层的结晶度,降低其在体液中的降解.经碱处理的等离子喷涂钛涂层,生物活性有了明显的改善.等离子喷涂硅灰石和硅酸二钙陶瓷是一类不同于传统磷酸钙系的新型生物活性材料,其性能和结构已被初步研究.同时介绍了等离子喷涂人工骨涂层材料在这几个方面的近期研究进展. 相似文献
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利用等离子喷涂方法制备Al2O3-40% TiO2涂层,对涂层进行激光重熔处理.分别对等离子喷涂层和激光重熔涂层进行耐冲蚀磨损性能试验,研究了激光重熔对Al2O3-40% TiO2等离子喷涂层耐冲蚀性能的影响.结果表明,激光重熔消除了Al2O3-40% TiO2等离子喷涂层的层状结构,使得等离子喷涂层中γ-Al2O3转变为α-Al2O3,形成了α-Al2O3+TiAl2O5稳定结构.激光重熔后的涂层组织致密均匀、硬度高,具有冶金结合特征,使得耐冲蚀性能得到极大提高,其磨损特征为冲蚀粒子冲击作用下产生的裂纹、破碎与块状剥落. 相似文献
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Calcium phosphate materials such as hydroxyapatite (HA) have biocompatible properties that can promote osteogenesis or new
bone formation. Thermal spraying is an economical and effective process for coating the hydroxyapatite onto metal. It has
been reported that plasma spraying changes the degree of crystallinity as well as the phase composition of the HA. This article
reports the preparation and characterization of HA powders and coatings by two thermal spray processes (plasma and combustion
flame) and suggests that the state of the starting powder adversely affects the coating characteristics. The raw HA powders
are synthesized through a chemical reaction involving calcium hydroxide and orthophosphoric acid. Phase analysis using an
X- ray diffractometer revealed that the synthesized powder consists of predominantly the HA phase. Calcined and crushed HA
powders of various size ranges were fed into the plasma jet to produce HA coatings on metallic substrates. In addition, some
HA powders were sprayed into distilled water by plasma spraying and combustion flame spraying to study powder melting characteristics.
Other samples were plasma sprayed onto a solid rotating target to study atomization and impact behavior. The morphology of
the rapidly solidified powders and thermal sprayed coatings were examined by scanning electron microscopy (SEM). An X- ray
sedimentation particle size analyzer, laser diffraction particle size analyzer, and image analyzer performed the particle
size analysis. Preliminary results indicate that particle cohesion, size range, and thermal treatment in the plasma affect
the phase and structure of the as- sprayed coating, and some post- spray treatment may be necessary to produce a dense and
adherent coating with the desired biocompatible properties. 相似文献
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为使AlSi-20%Al/Ni超音速等离子喷涂涂层获得优良的结合性能,采用正交实验法研究了喷涂距离、喷涂电压、喷涂电流等喷涂工艺参数对结合强度的影响。利用X射线衍射、扫描电镜等手段对涂层的相组成和断口形貌进行分析,利用WDW-E100D微机控制式万能拉伸试验机对涂层结合强度进行测试。结果表明:涂层由AlSi和AlNi两相组成,影响AlSi-20%Al/Ni涂层结合强度工艺参数的主次顺序为喷涂距离、喷涂电压、喷涂电流,优化后的工艺参数为主气流量3.2m3/h,喷涂电流为380A,喷涂电压为130V,喷涂距离为90mm,在此参数下制备的涂层组织致密,其结合强度为65.5MPa。 相似文献
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Aninvestigationonplasmasprayingwithartificialbonepowderandbondingcharacteristicsofcoating¥TianLi;LiJinglongandLinQiansheng(No... 相似文献
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热喷涂层由扁平粒子组成,呈层状结构。气孔不可避免地存在于涂层中,而这些气孔包括通常所指的微米级气孔以及亚微米级的气孔。亚微米级气孔由扁平粒子间的未结合界面和扁平陶瓷粒子内所产生的显微裂纹构成。业已开发成功陶瓷涂层的电镀技术,并利用电镀的钢在涂层断面上的分布,揭示热喷涂Al2O3涂层的的真实气孔结构的方法。该方法的最重要之处在于直观地揭示热喷涂层的扁平陶瓷粒子间的未结合界面。本论文将电镀技术应用于传统的等离子、低气压等离子以及爆炸喷涂法喷制的Al2O3涂层,用扁平粒子间平均结合率和扁平粒子的平均厚度为结构参数定量地评价涂层结构。考察热喷涂方法对扁平粒子间结合的影响。 相似文献
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The effects of Ni-50 mass% Cr alloy coating, that is plasma-sprayed onto the fire-side of steam generating tubes in a heavy
oil-fired boiler, on the high temperature corrosion resistance were examined. One of the severe environments in the industrial
manufacturing facilities, where thermal sprayed coatings are employed, is the high temperature corrosion such as the oxidation,
sulfidation, and low melting fuel ash corrosion in the fire-side of boiler tubes. In the fossil fuel-fired steam generating
boiler facilities, the degradation or failure of steam generating tubes that were derived from the contaminants in a lower
grade fuel have often occurred. The situation of degradation of the water evaporator and superheater tubes and corrosion-preventing
effects of plasma sprayed coating are described. The enhanced effects of plasma sprayed Ni-50 mass% Cr alloy coating for the
suppression of hot corrosion failure of the steam generating tubes of boiler are summarized. 相似文献
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A comparative study of tribological behavior of plasma and D-gun sprayed coatings under different wear modes 总被引:3,自引:0,他引:3
Sundararajan G. Prasad K. U. M. Rao D. S. Joshi S. V. 《Journal of Materials Engineering and Performance》1998,7(3):343-351
In recent years, thermal sprayed protective coatings have gained widespread acceptance for a variety of industrial applications.
A vast majority of these applications involve the use of thermal sprayed coatings to combat wear. While plasma spraying is
the most versatile variant of all the thermal spray processes, the detonation gun (D-gun) coatings have been a novelty until
recently because of their proprietary nature. The present study is aimed at comparing the tribological behavior of coatings
deposited using the two above techniques by focusing on some popular coating materials that are widely adopted for wear resistant
applications, namely, WC-12% Co, A12O3, and Cr3C2-MCr.
To enable a comprehensive comparison of the above indicated thermal spray techniques as well as coating materials, the deposited
coatings were extensively characterized employing microstructural evaluation, microhardness measurements, and XRD analysis
for phase constitution. The behavior of these coatings under different wear modes was also evaluated by determining their
tribological performance when subjected to solid particle erosion tests, rubber wheel sand abrasion tests, and pin-on-disk
sliding wear tests. The results from the above tests are discussed here. It is evident that the D-gun sprayed coatings consistently
exhibit denser microstructures and higher hardness values than their plasma sprayed counterparts. The D-gun coatings are also
found to unfailingly exhibit superior tribological performance superior to the corresponding plasma sprayed coatings in all
wear tests. Among all the coating materials studied, D-gun sprayed WC-12%Co, in general, yields the best performance under
different modes of wear, whereas plasma sprayed Al2O3 shows least wear resistance to every wear mode. 相似文献
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Yu-peng Lu Yan Jiao Jian-Hua Wang Wen-Hua Xu Gui-Yong Xiao Rui-Fu Zhu 《Surface & coatings technology》2012
Pores in hydroxyapatite (HA) coatings affect their mechanical and biological performances, and so far pore characteristic and formation mechanism are not fully understood. In the present study, microstructural observations on plasma sprayed HA coating have been carried out, indicating that globular pores exist commonly on coating surface, cross-sectional facet and fracture surface. Analysis of HA particles plasma sprayed into water shows that hollow HA spheres were formed, and the hollow spheres will transform into globular pores when they impact onto the substrate. 相似文献