等离子喷涂涂层材料

本文介绍中国科学院上海硅酸盐研究所在研制，开发、应用等离子喷涂涂层材料方面所取得的一些进展，主要有(1)涂层的物理，力学，热学性能和微观结构；(2)涂层性能与其微观结构间关系；(3)涂层的摩擦．磨损行为和机理，(4)涂层的生物相容性，(5)涂层在工业上的应用。     

钛合金表面等离子喷涂涂层材料的研究进展

介绍了钛及钛合金表面等离子喷涂涂层材料的研究进展,主要从钛合金表面等离子喷涂陶瓷材料耐磨涂层、固体润滑减摩涂层、生物活性涂层、功能涂层等几方面进行了简要的介绍。并对钛及钛合金表面等离子喷涂涂层材料的发展趋势进行了展望。     

微束等离子喷涂Mo涂层

采用微束等离子喷涂方法在Q235上制备了Mo涂层.研究喷涂电流、喷涂距离对涂层组织结构和性能的影响.采用光学显微镜观察涂层的组织结构并计算孔隙率,测试涂层的显微硬度和结合强度,并记录粉末沉积率.结果表明,在本试验条件下微束等离子喷涂电流与喷涂距离对涂层组织和性能产生较大的影响.适当工艺参数条件下粉末沉积率高于80 %,可以获得显微硬大于400 HV_(0.1),平均结合强度仍然大于40 MPa的涂层.     

微束等离子喷涂NiCrBSi涂层

采用微束等离子喷涂方法在St37低碳钢上制备了NiCrBSi涂层.研究了基材温度、等离子气体流量、喷涂距离和电流强度等工艺参数对涂层组织结构和性能的影响.采用光学显微镜观察涂层的组织结构,用Perthometers M4P 150测定涂层的表面粗糙度,以及用LECO TC316气体抽提仪检测涂层的氧含量.结果表明,在试验条件下,喷涂参数对涂层组织和性能产生较大的影响.随着电流和基材温度的增加涂层的粗糙度降低,涂层的氧含量随着基材温度和喷涂距离的增加而增加.大多数涂层的显微硬度大于600 HV0.2.尽管粒子速度较低,涂层的平均结合强度仍然大于50 MPa.     

等离子喷涂制备典型涂层研究进展

从航空航天到交通运输、电子设备和医疗器械等,大大小小的行业中均可见到涂层的应用,涉及到这些领域的涂层种类主要有耐磨、耐蚀涂层、热障涂层、压电陶瓷涂层和生物陶瓷涂层等。等离子喷涂技术具有喷涂材料范围广、工艺简单等优点,是制备上述典型涂层的常用工艺方法。虽然同种工艺可制备出不同种类涂层,但由于所选的喷涂材料、喷涂参数不同,所获得的涂层性能和涂层结构之间也存在着一定差异,须对等离子喷涂各类涂层的研究进行分析与总结。基于此,文中简要介绍了国内外等离子喷涂涂层的应用现状,之后从不同种类涂层功能需求和技术特点出发,分析喷涂工艺对涂层结构和性能的影响。最后对提升涂层性能的工艺方法进行总结,并对今后等离子喷涂涂层技术的发展趋势进行了展望。     

医用镁合金等离子喷涂羟基磷灰石涂层研究

为了提高医用镁合金的表面耐蚀性和生物相容性,采用等离子喷涂技术在镁合金表面制备羟基磷灰石(HA)涂层.研究结果表明,镁合金表面所制备的HA涂层与基体结合牢固,界面无裂纹、气孔等缺陷.相组成为生物相容性较好的HA和少量的Ca3(PO4)2(TCP),显微组织具有层状特征,涂层表面存在一些有利于骨长人的孔隙.涂层的弹性模量约为19.825 GPa,接近骨的弹性模量,涂层表面硬度为300～350 HV.腐蚀试验和钙磷沉积试验结果表明HA涂层具有较好的耐蚀性和骨诱导性.     

等离子喷涂纳米氧化锆涂层研究进展

等离子喷涂氧化锆涂层用作航空和陆基发动机热保护已经有数十年历史,取得了很好的效果.为了进一步提高发动机的效率和寿命,人们致力发展新的涂层材料和改进现有涂层的结构和性能.文中叙述了中国科学院上海硅酸盐研究所在等离子喷涂纳米氧化锆涂层方面的近期研究结果.通过工艺参数调整控制涂层微观结构,制备了具有纳米结构的3 % Y2O3-ZrO2涂层;较为系统地测定了涂层的物理、力学和热物性能;对比了纳米和常规氧化锆涂层的抗热震行为,初步阐述了不同涂层的热震破损失效机制;对涂层的生物活性和细胞相容性亦进行了初步评价.此外,还展望了等离子喷涂纳米氧化锆涂层的未来研究工作方向.     

等离子喷涂纳米陶瓷涂层研究

从纳米喂料的制备、纳米陶瓷涂层的制备及其结构和特性三方面评述了等离子喷涂纳米陶瓷涂层研究的进展,探讨了等离子喷涂纳米陶瓷涂层研究中存在的主要问题,并展望了等离子喷涂纳米陶瓷涂层的发展前景。     

等离子喷涂结构涂层研究

介绍了等离子喷涂的原理及特点;综述了等离子喷涂结构涂层的研究进展,包括耐磨涂层、热障涂层、耐蚀涂层;介绍了等离子喷涂结构涂层的复合处理技术;展望了等离子喷涂结构涂层的发展前景。     

等离子喷涂陶瓷涂层的应用

简述等离子喷涂陶瓷涂层的研究进展与现状,依据陶瓷涂层应用的分类,从等离子喷涂陶瓷涂层的耐磨涂层、热障涂层、耐蚀涂层、超导涂层、压电陶瓷涂层、生物活性涂层方面介绍了目前常用的等离子喷涂陶瓷材料的性能及其应用的研究现状。     

喷涂工艺参数对硅灰石涂层结构的影响

采用等离子喷涂方法,在不同喷涂距离、主气流量和喷涂功率下制备硅灰石涂层.使用扫描电镜观察了涂层的微观形貌,研究了喷涂工艺参数对涂层结构的影响.结果表明,在较大主气流量下,随着喷涂距离增加,涂层粒子扁平化程度降低,涂层内孔隙逐渐增多;在较小主气流量下,涂层粒子扁平化程度随喷涂距离增加呈现先增加后减小的趋势.主气流量增加,涂层致密,粒子扁平充分.喷涂功率增加,粒子熔化好,涂层致密;但随喷涂功率进一步增加,涂层中出现较多的圆形孔隙.喷涂工艺参数对涂层结构的影响主要通过影响熔融粒子的温度和速度所致.     

An investigation on plasma spraying with artificial bone powder and bonding characteristics of coating

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On-line temperature monitoring and process diagnosis of plasma sprayed coatings

On-line temperature monitoring of plasma sprayed coating is presented, which is based on IR pyrometery combined to robot trajectories. Temperature fields of the substrate before spraying and the deposited coating when the damage happens are taken to investigate the temperature fluctuation information. Experimental results demonstrate that coating damage always occurs in the temperature transition area of the substrate from the higher to the lower, as well as the higher temperature area. The temperature difference between the peak and the mean of the relevant regions is beyond 30-50 ℃ or even higher. This case provides the omen of coating damage and the focusing scopes for the process control of coating temperature in plasma spraying.     

微束等离子喷涂制备羟基磷灰石涂层

采用微束等离子喷涂系统制备羟基磷灰石涂层,通过扫描电子显微分析(SEM)和X射线衍射分析(XRD)对涂层形貌、相组成和结晶度进行了研究.结果表明,随着喷涂电流和离子气流量的增加,羟基磷灰石粒子的熔化和撞击后的铺展更充分,在70～130 mm范围内随着喷涂距离的增加粒子熔化程度增加.适当的喷涂工艺条件下微束等离子喷涂制备羟基磷灰石涂层的结晶度可以相当或高于传统大气等离子喷涂制备的涂层,有利于涂层在体液环境中稳定性的提高.     

Antibacterial properties of vacuum plasma sprayed titanium coatings after chemical treatment

Implant-related infection is one of the common clinical complications that cause high rates of mortality and morbidity in orthopedic surgery. Endowing implant antibacterial properties is a useful method to reduce such infection. In this paper, vacuum plasma sprayed titanium coatings were treated by NaOH solution firstly, and then antimicrobial silver was introduced into the coatings by immersing in 0.02 mM (denoted as CA1), 0.06 mM (denoted as CA2) and 0.1 mM (denoted as CA3) Ag⁺ containing calcification solution. Antibacterial property of the treated titanium coatings was examined by employing three types of bacteria stains, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. X-Ray diffraction and scanning electron microscopy were used to observe the phase composition and surface morphology of the modified titanium coatings. Results showed that all of the three kinds of coatings exhibited more than 90.00% antibacterial ratio except CA1 to Staphylococcus aureus which is 63.30%. The release of silver in physiological environment was monitored and it was found that the excellent antibacterial property of the treated coatings was attributed to the release of silver.     

Hydroxyapatite coatings for biomedical applications deposited by different thermal spray techniques

Thermally sprayed hydroxyapatite (HAp) coatings are widely used for various biomedical applications due to the fact that HAp is a bioactive, osteoconductive material capable of forming a direct and firm biological fixation with surrounding bone tissue.Bioceramic coatings based on nanoscale HAp suspension and microscale HAp powder were thermally sprayed on Ti plates by high-velocity suspension flame spraying (HVSFS) technique and atmospheric plasma spraying (APS) as well as high velocity oxy fuel spraying (HVOF) technique. HVSFS is a novel thermal spray process developed at IMTCCC, for direct processing of submicron and nano-sized particles dispersed in a liquid feedstock.The deposited coatings were mechanically characterized including surface roughness, micro hardness and coating porosity. The bond strength of the layer composites were analyzed by the pull-off method and compared for the different spray techniques. Phase content and crystallinity of the coatings were evaluated using X-ray diffraction (XRD). The coating composite specimen and initial feedstock were further analysed by scanning electron microscope (SEM) and rheology analysis.     

微束等离子喷涂氧化锆增韧羟基磷灰石复合涂层

采用微束等离子喷涂方法,在Ti-6Al-4V基体上制备了羟基磷灰石 氧化锆(70HA-30ZrO2,质量分数,%)复合涂层.将复合涂层置于模拟体液中分别浸泡了3,7,14,28 d并观察表面磷灰石的生长情况以评价涂层生物活性.采用扫描电镜(SEM)和X射线衍射(XRD)分析技术对涂层浸泡前后的表面形貌和相组成进行了研究.结果表明,涂层中ZrO2主要以立方相存在;喷涂过程中羟基磷灰石(HA)出现了一定的分解,产生大量的α-Ca3(PO4)2杂质相.HA涂层熔化效果很好,但涂层中有未熔化的ZrO2颗粒.涂层在模拟体液中浸泡28 d后表面可以形成磷灰石,说明涂层具有很好的生物活性.     

晶须增韧等离子喷涂陶瓷涂层的可控制备与力学性能研究

针对新一代航空发动机和重型燃气轮机对长寿命、高韧性热障涂层的迫切需求,本文通过喷雾造粒法制备了长径比为10的ZrO2晶须复合YSZ喷涂粉末,采用SAPS技术制备了YSZ/ZrO2晶须増韧陶瓷复合涂层,对复合涂层的工艺参数进行优化,研究了熔融指数对陶瓷复合涂层微观结构的影响规律;通过狭缝法收集单个摊片的实验,阐明了ZrO2晶须增韧YSZ陶瓷涂层的形成机理,建立了晶须増韧陶瓷涂层的微观结构与热力学性能的内在关系。基于晶须弥散分布于复合涂层未熔颗粒区的特征,相比纳米结构YSZ涂层,YSZ/ZrO2晶须増韧陶瓷复合涂层的断裂韧性与热循环寿命均提高一倍。     

Erosion-resistance of plasma sprayed coatings

Cr₃C₂/NiCr, ZrO₂/NiCr, WTiC₂/NiCr, and X40 were plasma sprayed on the substrate 1Cr18Ni9Ti in order to solve the erosion wear at high temperature encountered in the oil-refining industry. A series of properties of the coatings, including their microstructure, hardness, and erosion-behavior, have been tested. The test results show that the properties of the coatings have a significant effect on their erosionresistant performance. Good erosion-resistant materials need to be hard and tough. Both Cr₃C₂/NiCr and X40 have good erosion resistance at elevated temperature.     

Plasma sprayed cast iron coatings containing solid lubricant graphite and h-BN structure

Water-atomized cast iron powder of Fe-2.17 at.%C-9.93at.%Si-3.75at.%Al were deposited onto an aluminum alloy substrate by atmospheric direct current plasma spraying to improve its tribological properties. Preannealing of the cast iron powder allows the precipitation of considerable amounts of graphite structure in the powder. However, significant reduction in graphitized carbon in cast iron coatings is inevitable after plasma spraying in air atmosphere due to the in-flight burning and dissolution into molten iron droplets. Hexagonal boron nitride (h-BN) powders, which have excellent lubricating properties like graphite, were incorporated into the cast iron powder as a solid lubricant by the sintering process (1300°C) to obtain protective coatings with a low friction coefficient. The performance of each coating was evaluated using a ring-on-disk-type wear tester under a paraffin-based oil condition in an air atmosphere. A conventional cast iron liner, which had a flaky graphite embedded in the pearlitic matrix, was also tested under similar conditions for comparison. Sections of worn surfaces and debris were characterized, and the wear behavior of plasma-sprayed coatings was discussed. The original version of this paper was published in the CD ROM Thermal Spray Connects: Explore Its Surfacing Potential, International Thermal Spray Conference, sponsored by DVS, ASM International, and HW International Institute of Welding, Basel, Switzerland, May 2–4, 2005, DVS-Verlag GmbH, Düsseldorf, Germany.