一种等离子喷涂钼基非晶纳米晶涂层

一种钼基非晶纳米晶复合涂层及制备方法，涉及等离子喷涂钼基合金涂层，特别是涉及非晶纳米晶复合涂层。本发明针对过去利用热喷涂技术制备单一的非晶涂层或纳米结构涂层存在的问题，提出由钼基多元素非晶纳米晶合金粉末作为喷涂粉末，     

纳米YSZ热障涂层制备工艺及涂层环境试验研究

以结合强度为衡量指标,由L9（34）试验确立了等离子喷涂纳米YSZ制备热障涂层的最佳工艺参数。采用SEM对涂层微观组织结构及涂层相关性能进行了研究分析。结果表明,经优化工艺参数喷涂制备的YSZ热障涂层结合强度可达38.26MPa,厚度为0.37mm的该涂层在600℃时的隔热温度达到70℃,且该涂层具有良好的环境适应性。     

等离子喷涂制备铁基非晶-纳米复合涂层

以一种多元素铁基非晶合金粉末(含C,Si,B,Cr,W,Mo,Ni,Fe等)作为喷涂材料,用大气等离子喷涂在316L不锈钢基体上制备涂层.用X射线衍射仪检测涂层的晶型结构,扫描电镜观察涂层的形貌,透射电镜观察涂层的微观组织结构,显微硬度仪测量涂层的显微硬度,纳米压痕仪测量涂层的硬度及弹性模量,并用谢乐公式计算了晶粒尺寸.结果表明:所制备的涂层均匀致密,与基体结合良好;涂层含有非晶和纳米颗粒;这种非晶-纳米复合涂层具有很高的硬度和弹性模量.     

制备工艺方法对 NiCrFeMo 涂层组织和性能影响研究

采用等离子喷涂、 超音速火焰喷涂和冷喷涂工艺制备了 NiCrFeMo 涂层, 并对涂层的金相性能、 不同基体 材料下涂层的结合性能、 不同温度下涂层的耐磨性能进行了检测。 实验结果表明： 采用冷喷涂工艺制备的涂层孔 隙率最低, 对应涂层的结合强度最高, 但冷喷涂工艺制备的涂层对基体材料较为敏感, 而超音速火焰喷涂和等离 子喷涂受基体材料影响不大。 在室温下, 冷喷涂涂层显示出较优的耐磨性能, 在高温下超音速火焰喷涂涂层显示 出较优的耐磨性能。     

电弧喷涂制备含非晶/纳米晶涂层及其性能研究

采用电弧喷涂技术,在低碳钢基体上制备了含非晶/纳米晶铁基涂层.利用光学显微镜、扫描电镜、透射电镜和X射线衍射仪对涂层形貌、显微组织结构和相组成进行了研究.结果表明,涂层各区域的组织均匀一致,由熔融和半熔化状态的液滴的连续堆积而成层状,致密度高,孔隙率低,氧化物含量较少,并具有很高的硬度和耐磨性,显微硬度为1 393.52 HV0.1,同等试验条件下,涂层耐磨粒磨损性能为Q235钢的18.7倍.     

等离子喷涂高强韧纳米TiO2涂层的制备及其力学性能研究

为提高大气等离子喷涂（APS）TiO2陶瓷涂层的结合强度及其摩擦磨损性能,采用喷雾造粒的纳米结构TiO2粉末为原料,利用APS工艺制备出TiO2陶瓷涂层,研究了涂层的显微组织、相组成、力学性能和摩擦磨损性能,并与常见的微米级TiO2粉末制备的陶瓷涂层组织性能进行了对比。结果表明,微米TiO2粉在喷涂前后相成分从板钛矿变为主为金红石和锐钛矿的混合相;而纳米团聚的TiO2粉喷涂前后无明显的相成分变化,均以金红石相为主。纳米TiO2涂层的孔隙率为1.4%,低于微米粉涂层的3.3%。纳米TiO2涂层的力学性能优于微米涂层,微米涂层硬度为934.2 HV0.1,而纳米涂层的硬度为1 349 HV0.1;纳米和微米涂层的弹性模量分别为203.1和185.8 GPa;纳米涂层的断裂韧性为2.1 MPa?m1/2,略高于微米涂层的2.0 MPa?m1/2;纳米涂层的结合强度可达46.8 MPa,是微米涂层的3.18倍（14.7 MPa）。此外,在相同的摩擦条件下,纳米TiO2涂层的摩擦因数为0.69,比微米TiO2涂层更低,纳米涂层的磨损体积也比微米涂层更少。综合来说,纳米TiO2涂层相对于微米级TiO2涂层体现出更好的综合力学性能。     

热喷涂涂层的制备

对热喷涂层金相试样制备进行了介绍 ,并对一些技术问题给予提示。     

纳米氧化锆热障涂层完整性研究

分别采用超音速火焰喷涂技术(HVOF)与大气等离子喷涂技术(APS)喷涂NiCrAlY粘结底层, APS喷涂纳米氧化锆的方法获得了两种热障涂层(涂层A与B),并评估了热震试验前后涂层的完整性。试验结果表明:二者热震前,完整性基本相当,涂层结合强度为(55±5)MPa;但是经过热震试验后,涂层A具有更好的完整性。     

高效能超音速等离子喷涂射流与涂层特点

超音速等离子喷涂技术是热喷涂技术发展的重要方向之一。通过简化模型计算,比较了常见热喷涂技术的粒子飞行时间、等离子喷嘴喉口的能量密度,探讨了高效能超音速等离子喷涂典型陶瓷、易氧化纯金属、金属陶瓷复合材料、非晶材料等粒子飞行特征和涂层主要性能。结果表明:高效能超音速等离子喷涂技术(HEPJet)所具有的高温、高速双高特点,使其能够对各种熔点、易氧化、易失碳材料实现低成本、高效率、高质量的涂层制备,是一种非常具有应用潜力的热喷涂技术。     

双丝电弧喷涂方法制备功能梯度涂层

本文介绍了一种从粘结层到面层成分和性质逐渐不同的功能梯度涂层(FGC).在涂层制备过程中,使用了混合喷嘴,采用双丝喷涂工艺.为了提高涂层与基体的结合力,首先在基体上喷涂金属丝材作为粘结层,为提高涂层的耐磨性,又将粉末状的硬质材料喷射到含有大量的熔融丝材的火焰中制备出面层涂层.结果表明,功能梯度涂层是由纯金属部分和含有硬...     

超音速等离子喷涂纳米防污陶瓷涂层研究

以NiCr合金为底层,含防污成分的纳米Al_2O_3-13%TiO_2为面层,采用超音速等离子喷涂方法制备纳米防污陶瓷涂层。研究了不同工艺对涂层截面形貌、孔隙率、显微硬度及结合强度的影响,探讨了涂层的防污性能,获得了较优的喷涂工艺参数:Ar流量3.6～3.8 m~3/h,H_2流量0.4 m~3/h,电流400～420A,电压150V,喷距100mm,送粉量30g/min。采用较优超音速等离子喷涂工艺制备的纳米防污陶瓷涂层孔隙率可达0.8%,HV_(0.3)≥987,结合强度≥35.15 MPa,并且抗海生物附着性能优良。     

Sol-Gel Derived Nanocrystalline Fluoridated Hydroxyapatite Powders and Nanostructured Coatings for Tissue Engineering Applications

Nanocrystalline fluoridated hydroxyapatite (FHA) powders and coatings with a chemical composition of Ca₁₀(PO₄)₆OH_2–x F _x (where x values were selected equal to 0.0 ,0.5, 1.0, 1.5, and 2.0) were prepared through a modified simple sol-gel technique in comparison with conventional alkoxide-based sol-gel route. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, pF-meter with a fluorine-sensitive electrode, and inductively coupled plasma–optical emission spectroscopy (ICP-OES) analysis techniques were employed in order to evaluate phase composition, particle size distribution, morphology, functional groups, fluorine content, and purity of prepared FHA nanopowders, respectively. SEM analysis was used to study the surface morphology and cross section of the FHA coatings, deposited on 316L stainless steel substrate. Results indicated that single-phase and homogeneous FHA nanopowders with carbonate peaks in the FTIR spectrum were synthesized through the modified sol-gel technique. TEM analysis revealed that fluorapatite (FA) powder was composed of nanosized particles, ~25 nm in size, with polyhedron shape and straight corners. In the modified sol-gel technique, polymerization and gelation kinetic of the sol were significantly improved without any need to use additives or pH control. Uniform, dense, well-adhered, and compacted FHA coatings were formed on the 316L stainless steel substrate after 24 hours of aging.     

Coefficient of Friction Measured from Nano- to Macro-Normal Loads on Plasma Sprayed Nanostructured Cermet Coatings

Alumina dispersed FeCuAl-based nanostructured cermet coatings were deposited from nanostructured powders by atmospheric plasma spraying on low carbon steel substrates. Nanostructuring was retained in the deposited coatings which exhibit up to four distinctive phases as revealed by electron microscopy. In this study, the friction behavior of the distinctive phases at nano-normal load scale was investigated alongside their contribution to the overall friction behavior at macro-normal load scale. Friction behavior at nano-normal load scale was investigated by lateral force microscopy, whereas conventional tribometers were used for investigations at micro and macro-normal loads. It appeared that, the friction measured at nano-normal loads on individual phases is dictated by both composition and hardness of the corresponding phases, and thus influences the overall friction behavior of the coatings at macro-normal loads. Moreover, the coefficient of friction at macro-normal loads differs from the one at nano-normal loads, and deviates from Amonton’s friction law.     

大气等离子喷涂工艺对纳米结构和传统Yb2SiO5 涂层微观结构的影响

纳米材料由于具有一些独特的效果而表现出了独特的性能,纳米结构稀土硅酸盐被认为是很有前景的环境 障碍涂层 ( EBC ) 材料之一。稀土硅酸盐材料中Yb2SiO5 因其卓越的高温相稳定性、对水蒸气环境的耐久性、低 热导率以及优秀的化学稳定性受到了研究者们的广泛关注。本文研究了大气等离子喷涂工艺 ( APS ) 参数对纳米 结构和传统Yb2SiO5 涂层微观结构的影响,并研究了相同大气等离子喷涂工艺下,纳米结构Yb2SiO5 喂料和传统 Yb2SiO5 喂料对涂层微观结构的影响,分析了APS 制备过程中不同结构喂料对涂层结构影响机制。结果表明：相 同喷涂参数制备的纳米结构Yb2SiO5 涂层孔隙率低于传统Yb2SiO5 涂层,以及纳米结构Yb2SiO5 涂层的铺展性和 融化度均优于传统Yb2SiO5 涂层,表明纳米结构Yb2SiO5 涂层为很有前途的环境障碍涂层之一。     

High Temperature Erosion Performance of Nanostructured and Conventional TiAlN Coatings on AISI-304 Boiler Steel Substrate

According to modern design philosophy better overall performance can be obtained with the modification of the surface structure and their properties without damaging underlying bulk material or substrate. The surface engineering can be classified in two broad classes: surface modification and surface coating. In the present research TiAlN coating was deposited on AISI-304 grade boiler steel using three different techniques, out of which two were thin nano coatings deposited at different temperatures of 500 and 200 °C developed by Oerlikon Balzers rapid coating system machine under a reactive nitrogen atmosphere. One conventional coating of TiAlN was deposited by plasma spraying method. The coated samples were characterized relative to their coating thickness, microhardness, porosity and micro structure. The optical microscopy, the X-ray diffraction analysis and field emission scanning electron microscope (FESEM with EDAX attachment) analysis have been used to identify various phases formed after coating deposition on the surface of AISI-304 grade boiler steel. The erosion studies were conducted on uncoated as well as coated specimens in simulated coal fired boiler environment using an air jet erosion test rig at various impingement angles of 30°, 60° and 90°. The alumina particles of average size of 50 µm were used as erodent at a velocity of 35 m/s. The eroded samples were analysed with SEM/EDAX and optical profilometer. The main objective of this research work was to increase the life of boiler tubes by using nanostructured and conventional TiAlN coatings and at the same time to compare the performance of coatings with respect to bare AISI-304 grade boiler steel. The nanostructured TiAlN coatings has shown minimum erosion rate as compared to conventional TiAlN coating and uncoated AISI-304 grade boiler steel. Maximum erosion was observed at an angle of 30° as compared to 60° and 90° indicative ductile behaviour.     

电化学法和沉淀法制备的纳米结构CeO_2的微观结构比较

利用X射线衍射、X射线小角散射、扫描电子显微镜、透射电子显微镜等分析手段对电化学法、沉淀法制备的纳米结构的CeO2 的微观结构进行了比较 ,发现电化学法制备CeO2 是由分散的纳米颗粒组成 ,而沉淀法制备的CeO2 则是由粗大片状颗粒组成 ,而该片状颗粒具有纳米的结构。电化学法的CeO2 比沉淀法CeO2 具有更细的纳米结构     

电化学法和沉淀法制备的纳米结构CeO2的微观结构比较

利用X射线衍射、X射线小角散射、扫描电子显微镜、透射电子显微镜等分析手段对电化学法、沉淀法制备的纳米结构的C eO2的微观结构进行了比较，发现电化学法制备CeO2是由分散的纳米颗粒组成，而沉淀法制备的Coeh则是由粗大片状颗粒组成，而该片状颗粒具有纳米的结构。电化学法的CeO2比沉淀法CeO2具有更细的纳米结构。     

海绵钛还原蒸馏反应器外表面金属基防护涂层研究

应用热喷涂技术制备的海绵钛还原蒸馏反应器外表面金属基防护涂层由高cr合金底层和Al-Si合金面层组成。在海绵钛生产使用条件下,在金属基防护涂层之中以及涂层与基体金属之间发生合金元素的扩散,原位生成氧化铬,从而提高了涂层与基体金属的结合强度;涂层中的氧化铬与涂层表面的氧化铝共同作用,有效地减缓了高温氧化的发展,为反应器的钢铁基体提供有效的抗氧化防护。经过13个炉次生产过程的现场试验结果表明,金属基防护涂层对反应器的钢铁基体提供了非常有效的高温保护。