涂层缺陷对涂层失效与基体腐蚀行为的影响研究

通过对涂层缺陷、涂层起泡、湿附着力等研究领域的回顾，讨论了涂层缺陷对腐蚀性介质离子在涂层中的传输行为、涂层失效、基体腐蚀行为等方面的影响。在此基础上，针对涂层缺陷研究现状中存在的一些未解决问题，提出了诸如计算机支持技术等可能的解决方法。     

羟基磷灰石涂层人工关节应用研究

对羟基磷灰石的成骨效应进行了研究，对添加骨水泥不当而导致的羟基磷灰石涂层人工关节涂层脱落进行了分析。结果表明，对于羟基磷灰石涂层人工关节，应有涂层区和非涂层区，骨水泥只能在非涂层区填充，而在涂层区则应使羟基磷灰石涂层直接与骨组织接触。这种人工关节，不仅充分利用了羟基磷灰石良好的生物相容性和成骨效应，而且有利于手术后的短期机械固定和长期的生物固定。     

锌基烧结涂层基本工艺条件的探索

探索了球状锌粉锌基烧结涂层的基本工艺条件。观察并研究了所得涂层的形貌、涂导必锌粉规格对涂层性能的影响，比较了涂层与镀锌白钝层的耐蚀性能。实验结果表明，随着小粒径锌粉的增多，涂层减薄，铬含量提高，耐蚀性增强。     

锌—铬水系涂层的研究

采用超细片状金属锌粉和铬酸盐，有机还原剂等材料配制的水系涂层，该涂层具有很好的防蚀效果。经过扫描电镜，电子探针，Ｘ－衍射，化学分析，差热分析以及电化学方法研究了Ｚｎ－Ｃｒ水系涂层的组成和结构，并探讨了其对耐腐蚀性能的影响。     

纳米涂层的研究现状与展望

简述了纳米表面涂层制备工艺的研究现状，分析了气相沉积、热喷涂、电刷镀、化学镀和电沉积等不同工艺在制备纳米表面层中的应用情况。介绍了纳米涂层在超硬耐磨、耐腐蚀、耐高温热稳定性等方面研究的新进展，并对纳米涂层的应用范围和领域作了展望。     

锅炉受热面抗氧化磨蚀涂层的研究

分析了电厂锅炉受热面热腐蚀磨损原因，对锅炉受热面防护方法进行了总结，研究了几种电弧喷涂表面涂层抗热磨蚀性能，提出了电厂锅炉受热面采用的涂层防护方法，并对现场应用涂层进行检查，电弧喷涂镍铬钛涂层显示出最佳的抗锅炉热腐蚀性能。     

反应磁控溅射制备的SiO2防护涂层抗原子氧侵蚀性能研究

在原子氧侵蚀地面模拟设备中对Kapton和利用反应磁控溅射制备的SiO2涂层进行了原子氧暴露实验，并采用XPS和SEM等分析手段对暴露前后试样表面的物理和化学变化进行了研究．结果表明，Kapton试样遭受了严重的侵蚀，质量损失较大；SiO2涂层质量变化很小，对基体提供了良好的保护作用．XPS分析结果表明，反应溅射的SiO2涂层是富Si的，初始暴露时由于氧化反应而质量有少许增加，随时间延长，涂层变得完全符合化学计量．SiO2涂层在原子氧暴露后涂层的太阳吸收率、辐射率和反射系数均没有发生明显的变化．SiO2涂层较脆，易产生裂纹，原子氧会通过缺陷位侵蚀下面的基体材料，严重影响飞行任务的正常进行。     

用冲击刮削法测量封严涂层的力学性能

利用自制的电子冲击刮削试验机，测试封严涂层的冲击刮削载荷－位移曲线。曲线上的屈服点和最大点综合表征了封严涂层的可磨耗性和涂层与基体的结合强度。曲线所包围的面积为冲击刮削韧性，用它可表征涂层的抗冲蚀性，通过一次测量即可获得涂层的上述力学性能指标     

一种耐腐蚀涂层钢轨生产工艺

本发明公开了一种耐腐蚀涂层钢轨生产工艺，利用本方法可在钢轨的表面冷镀富锌涂层、富铝涂层或富锌铝涂层，使钢轨能适应各种较恶劣的环境。本发明通过下述技术方案予以实现：用冷镀方法在钢轨表面形成耐腐蚀涂层，包括如下步骤：(1)将钢轨置于处理液内进行除油、除锈处理，     

纳米金刚石复合涂层技术实现产业化应用

近日，由上海交通大学承担的863纳米材料专项课题“纳米金刚石复合涂层的应用与产业化”通过了专家验收，该课题成功开发出了纳米金刚石复合涂层技术并实现了产品的产业化。该课题采用化学气相沉积法（CVD），在硬质合金拉拔模具内孔和其他耐磨器件表面涂覆纳米金刚石复合涂层，研究得到了制备纳米金刚石涂层的成熟工艺，完成了纳米涂层结构和性能检测工作，利用纳米金刚石复合涂层技术研究开发出多种涂层拉拔模具和耐磨器件产品，     

Improved Tribocorrosion Properties of Ti6Al4V Alloy by Anodic Plasma Electrolytic Oxidation

Ti6Al4V alloy has good corrosion resistance due to the formation of the passive oxide films on the surface of Ti6Al4V alloy. However, Ti6Al4V alloy has poor tribocorrosion resistance in the seawater environment. Herein the present work, plasma electrolytic oxidation (PEO) with the electrolyte of glycerol and sodium borate is used to generate PEO coatings on the surface of Ti6Al4V alloy to improve its tribocorrosion properties. The microstructure and tribocorrosion properties of PEO coatings are investigated by using scanning electron microscopy, X-ray diffraction, and tribometer, respectively. The growth kinetics and the tribocorrosion mechanisms of PEO coatings are discussed in detail. It is shown in the results that PEO coatings deposited on the surface of Ti6Al4V alloy are composed of rutile and anatase phases. The surface hardness and thickness of PEO coatings are enhanced with the increase of the voltage and time. The wear rate of Ti6Al4V alloy with PEO coatings is significantly reduced in artificial seawater.     

Plasma-sprayed coatings for oxidation protection on creep of the Ti–6Al–4V alloy

Abstract

The titanium affinity for oxygen is one of the main factors that limit the application of its alloys as structural materials at high temperatures. The objective of this work was to estimate the influence of the plasma-sprayed coatings for oxidation protection on creep of the Ti–6Al–4V alloy, focusing on the determination of the experimental parameters related to the creep stages. Yttria (8 wt.%) stabilized zirconia (YSZ) with a CoNiCrAlY bond coat was air plasma sprayed on Ti–6Al–4V substrates. Constant load creep tests were conducted on the Ti–6Al–4V alloy in air for coated and uncoated samples and in a nitrogen atmosphere for uncoated samples at 600°C to evaluate the oxidation protection on creep of the Ti–6Al–4V alloy. The steady-state creep rate of the coated alloy is smaller than that of the uncoated alloy in air and nitrogen atmosphere. Results about the activation energies and the stress exponent values indicate that the primary and stationary creep, for all test conditions, was probably controlled by dislocation climb. The plasma-sprayed coatings increased the time to rupture and the strain at rupture is smaller than for uncoated samples tested in air.     

梯度结构羟基磷灰石生物活性涂层的性能

采用等离子喷涂系统在Ti6Al4V钛合金基体表面制备出真有梯度结构的羟基磷灰石生物活性梯度涂层,利用纳米硬度计等手段分析了生物活性涂层的梯度结构．结果表明：金属基体与陶瓷界面区域的弹性模量和硬度呈梯度变化;生物活性功能涂层的表面具有典型的多孔结构特征,整个涂层沿垂直基体方向从底层致密结构向表面层多孔结构过渡;涂层的成分从生物稳定性的底层至生物活性的表面层呈梯度变化,涂层表面成分为具有生物活性的羟基磷灰石．涂层的这种结构特征保持了涂层的生物活性,提高涂层与基体的结合强度（48．6MPa）。     

Ti6Al4V钛合金表面Ta2O5/Ta2O5-Ti/Ti多涂层的制备与性能研究

采用磁控溅射技术在Ti6Al4V钛合金表面制备了Ta_2O_5/Ta_2O_5-Ti/Ti多层涂层;利用扫描电子显微镜(SEM)、X射线衍射仪(XRD)和X射线光电子能谱仪 (XPS),分析了涂层的微观结构、物性组成和化学价态;通过划痕仪、纳米压痕仪、摩擦磨损试验机和电化学工作站,检测了涂层的结合强度、力学性能、摩擦系数和耐腐蚀性。研究结果表明,Ta_2O_5/Ta_2O_5-Ti/Ti多层涂层表面由峰型颗粒组成,粒径大小均匀,涂层结构致密。与Ti6Al4V相比,Ta_2O_5/Ta_2O_5-Ti/Ti多层涂层试样具有较小的摩擦系数,较高的腐蚀电位和较小的腐蚀电流密度,表现出良好的耐磨和耐腐蚀性能,能对Ti6Al4V合金植入材料起到较好的保护作用。     

医用植入材料Ti6Al4V的腐蚀与防腐研究进展

Ti6Al4V具有良好的生物相容性、力学性能和工艺性能,是当今医用植入体的首选材料。但Ti6Al4V植入人体后会被体液腐蚀并释致出对人体有毒副作用的金属离子,针对此问题,分析了医用植入材料Ti6Al4V在临床应用中的腐蚀行为及其被腐蚀后对人体的影响,综述了该材料防腐技术的研究进展,并对该材料表面改性研究提出了建议。     

Thermal Treatment Optimization of Electrodeposited Hydroxyapatite Coatings on Ti6Al4V Substrate

Thermal behavior of electrodeposited hydroxyapatite (HAP) coating on a titanium alloy (Ti6Al4V) is investigated in order to optimize the heat treatment conditions for this prosthetic material. The synthesized coatings are annealed in air atmosphere at 400, 600, 800, and 1000 °C, and then characterized by X‐ray diffraction (XRD) and selected area electron diffraction (SAED) for structure and phases analysis. Scanning and transmission electron microscopy associated to energy dispersive X‐ray microanalysis (SEM‐EDXS and STEM) are used for morphology and composition analysis. The results show that when the electrodeposited coating is annealed at temperatures greater than 600 °C, a well‐crystallized HAP is obtained with a notable change of its morphology. However, at these temperatures the surface of Ti6Al4V alloy (uncoated zones of the implant) is deteriorated by the formation of a thick surface oxide layer. Therefore, we limit the heat treatment temperature for the electrodeposited coatings on a Ti6Al4V alloy at 550 °C. At this optimized temperature it is demonstrated that the link between the coating and the substrate is improved and the crystallinity of the coating is controlled which make it well bioactive.     

Laser surface coating of Mo–WC metal matrix composite on Ti6Al4V alloy

Laser surface alloying of Mo, WC and Mo–WC powders on the surface of Ti6Al4V alloys using a 2 kW Nd-YAG laser was performed. The dilution effect upon the microstructure, microhardness and wear resistance of the surface metal matrix composite (MMC) coating was investigated. With a constant thickness of pre-placed powder, the dilution levels of the alloyed layers were found to increase with the incident laser power. The fabricated surface MMC layer was metallurgically bonded to the Ti6Al4V substrate. The microhardness of the fabricated surface layer was found to be inversely proportional to the dilution level. The EDAX and XRD spectra results show that new intermetallic compounds and alloy phases were formed in the MMC layer. With the existence of Mo content in the pre-placed powder, the β-phase of Ti in the MMC coating can be retained at the quenching process. With increasing weight percentage content of WC particles in the Mo–WC pre-pasted powder, the microhardness and sliding wear resistance of the laser surface coating were increased by 87% and 150 times, respectively, as compared with the Ti6Al4V alloy. The surface friction of the laser-fabricated MMC coatings was also decreased as compared with the worn Ti6Al4V substrate.     

FHA涂层的制备及生物活性

采用沉淀法制备了F掺杂HA的FHA(Ca_(10)(PO_4)_6(OH)F)粉末,并通过电泳沉积在钛合金(Ti6Al4V)表面制备了FHA涂层。通过X射线衍射(XRD),扫描电镜(SEM),能谱仪(EDS)研究了基体预处理方式对涂层形貌和结合力的影响,并且研究了涂层的生物活性。结果表明:酸处理后涂层表面有微裂纹存在,酸处理+碱处理后的涂层表面无裂纹并具有更高的结合强度;FHA涂层浸泡后表面形成缺钙类骨磷灰石,成花瓣状生长,长度为几百纳米,具有优良的生物活性。     

Improvement on the Oxidation Resistance of a Ti3Al Based Alloy by Cr1-xAlxN (0≤x≤0.47) Coatings

Cr1-xAlxN coatings have been deposited on a Ti3Al based alloy by reactive sputtering method. The results of the isothermal oxidation test at 800-900 ℃ showed that Cr1-xAlxN coatings could remarkably reduce the oxidation rate of the alloy owing to the formation of Al2O3 Cr2O3 mixture oxide scale on the surface of the coatings. No spallation of the coatings or oxide scales took place during the cyclic oxidation at 800℃. Ti was observed to diffuse into the coatings, the diffusion distance of which was very short, and the diffusion ability of it was proportional to the Al content in the coatings. Compared to Ti, Nb can diffuse much more easily through the whole coatings and oxide scales.     

铝合金表面Ti-Al双丝超音速电弧喷涂涂层的组织与性能研究

利用SAS－1型超音速电弧喷涂设备和钛、铝丝在适当的工艺条件下，在LY12铝合金表面制成了钛铝合金复合涂层。并利用金相显微镜、X射线衍射仪、扫描电镜、X射线能谱仪、电子探针等，对涂层的成分、相结构、显微结构、孔隙率及其结合强度、显微硬度和耐磨性进行了研究。结果表明，利用超音速电弧喷涂设备，可以在铝基表面形成低孔隙率小于2.8%，结合强度为29MPa，显微硬度HV0.2为631和干滑动磨损体积仅为LY12基体1／7的TiAl合金涂层。显微组织观察发现，涂层与基体间有冶金结合的迹象，组织结构分析表明，涂层由TiN（TiO)，Al,Ti,TiAl,Ti3Al等相组成。涂层的磨损机制可能以化合物等硬质相的剥落引起的磨粒磨损和氧化磨损为主。