医用Mg-1.0Ca合金微弧氧化膜生物相容性研究

使用微弧氧化技术对医用Mg-1.0Ca合金进行表面改性,采用扫描电镜(SEM)、X射线衍射(XRD)、析氢实验以及MTT法表征微弧氧化膜的性能。扫描电镜和XRD分析表明,氧化膜是一种典型的多孔结构,含有氧化镁、硅酸镁和硅酸钙等。在模拟体液中浸泡72 h后,氧化膜中钙和磷的含量显著增加,表明氧化膜具有很好的生物活性。析氢实验表明,微弧氧化能大大提高Mg-1.0Ca合金的耐蚀性。Mg-1.0Ca合金氧化前后的细胞毒性均为1级,表明基体以及氧化试样均具有良好的生物相容性。     

2种牙科贵金属铸造合金的细胞毒性研究

采用四甲基偶氮唑盐微量酶反应比色法(MTT法)对自行研制的2种Au-Ag-Pd-Cu牙科铸造合金的细胞毒性进行了研究。并用相差显微镜对细胞形态进行了观察分析。试验使用的细胞株为小鼠结缔组织成纤维细胞(L-929)，培养液为含5％小牛血清(FBS)的RPMI1640。结果表明：细胞在2种Au-Ag-Pd-Cu牙科铸造合金的浸渍液中培养3d和5d后，细胞形态良好，生长旺盛；2种合金的细胞毒性级别为0—1级，具有良好的细胞相容性。     

钛表面处理后表面能分析及对细胞附着的影响

采用微弧氧化（MAO）及水热合成（MAO-HS）法对纯钛表面进行处理，然后对其表面能进行分析，并观察成骨细胞在其表面的附着动力学变化及骨架蛋白表达。结果显示MAO表面能（50.6mj/m2）。细胞在MAO-HS表面的附着率明显高于MAO及Ti表面。细胞骨架蛋白在3种材料表面均表达良好，但彼此之间存在差异。因此钛有面采用微弧氧化及水热合成法处理后表面形貌及表面能发生改变，这种改变影响了细胞在其表面的生物为行为。     

低温超音速火焰喷涂铝-微弧氧化复合膜的制备与性能研究

先采用低温超音速火焰喷涂技术在AZ91D镁合金表面沉积一层致密的Al涂层,再采用微弧氧化技术进行微弧氧化处理,进而获得复合涂层。对热喷涂铝涂层微弧氧化的成膜过程、氧化膜微观结构和成分、复合涂层的耐腐蚀性能等进行了研究,并与在2024铝合金及AZ91D镁合金表面的微弧氧化过程和氧化膜层进行了对比。结果表明:在Al涂层上微弧氧化形成的微弧氧化膜呈多孔珊瑚状,相结构主要为γ-Al2O3,没有微裂纹产生,其微弧氧化过程与2024铝合金的微弧氧化大致相同;复合涂层具有良好的抗盐雾腐蚀性能,可显著提高镁合金的耐蚀性。     

微弧氧化法制备钛基HA/CS涂层及其生物学特性

采用微弧氧化法在医用钛表面制备羟基磷灰石（HA）/壳聚糖（CS）涂层。通过扫描电镜（SEM）、X射线衍射（XRD）仪、红外光谱（FTIR）仪分析涂层的形貌和物相,评价HA/CS涂层对成骨细胞的毒性及其在动物体内的生物活性,分析微弧氧化法制备钛基HA/CS涂层的特征及其在骨修复中应用的可能性。结果表明：微弧氧化法可在钛表面生成HA/CS涂层,厚度40±2 mm、粗糙度3.3±0.1 mm、孔隙率(30±2)%,孔隙近圆形、直径几微米到20 mm,结合强度20.5±1.1 MPa;涂层中HA与CS之间没有形成化学键,晶体HA占10%,平均粒径37 nm,非晶体HA占90%;钛基HA/CS涂层材料对成骨细胞增殖具有促进作用,无细胞毒性,在动物体内能够诱导骨小梁形成,具有高的生物活性。微弧氧化法制备的高生物活性钛基HA/CS涂层材料,在骨修复方面具有良好的应用前景     

微弧氧化技术的研究进展与展望

微弧氧化技术是近几年发展起来的表面处理工艺。目前,国外普遍采用微弧氧化来代替传统的阳极氧化。这项技术成为近几年材料表面处理的热点之一。通过对微弧氧化技术国内外研究现状的综述,指出微弧氧化技术存在的问题和发展趋势。     

金属复合材料微弧氧化研究进展

微弧氧化是一种在阀金属(Al、Mg、Ti等)及其合金表面原位生成陶瓷膜的表面处理技术。利用微弧氧化技术获得的膜层与基体结合力强,能改善材料的耐磨、耐蚀、耐热冲击以及绝缘性等性能。以微弧氧化的发展和成膜机理作为切入点,比较了单一合金与金属复合材料微弧氧化处理的异同,发现机理的研究主要围绕电击穿理论展开,具有阀金属特性的第二相有助于复合材料微弧氧化的进行,而其他的第二相则会阻碍微弧氧化成膜,使机理研究变得复杂。综述了电解液及添加剂、电压、电流密度、频率和占空比、温度和处理时间等对金属复合材料微弧氧化过程,及膜层微观结构、相组成、厚度、硬度以及耐磨、耐蚀性能的影响。最后指出了复合材料微弧氧化目前存在的问题,提出了需要从加强机理研究、优化工艺的参数、改进微弧氧化设备以及与其他技术相结合等研究方向着手,以进一步加快金属基复合材料微弧氧化处理及改善陶瓷膜的性能,推进微弧氧化技术的应用。     

医用Ti-6Al-4V合金表面超疏水涂层的制备及生物学性能

采用微弧氧化技术和氟硅烷修饰在医用Ti-6Al-4V合金表面构建超疏水涂层。考察微弧氧化电压对涂层表面形貌及粗糙度的影响,分析微弧氧化和超疏水涂层的相组成及元素化学状态以探讨超疏水表面的形成机制。初步研究超疏水试样的细胞毒性和抗菌性能。结果表明,随着微弧氧化电压的增加,涂层的表面粗糙度增大,而显微结构均匀性在440V最佳。经疏水处理后,试样的表面粗糙度较微弧氧化试样有所下降,而接触角随着电压的增加而先增大后减小,在440 V时获得最大值154.9°。微弧氧化涂层主要由锐钛矿及少量金红石TiO2相组成,并含有大量的–OH和一些磷的化合物,而超疏水试样表面存在大量的CF3、CF2和Si-O基团。全氟辛基三氯硅烷通过水解和脱水反应将氟硅烷嫁接于微弧氧化涂层上而形成超疏水表面。超疏水试样属于1级无毒材料,其细胞增殖率与Ti-6Al-4V合金无显著差异。此外,超疏水试样还具有一定的抗菌性,相对微弧氧化试样,其抗菌率可达93.03%。     

钛合金微弧氧化陶瓷膜的生物摩擦磨损性能

利用微弧氧化技术,采用甘油磷酸钙和乙酸钙混合电解液体系,在Ti6A14V钛合金表面制备了富含Ca,P元素的多孔陶瓷膜,研究了微弧氧化陶瓷层的摩擦学性能。在25%小牛血清润滑条件下,与Si3N4陶瓷球的滑动摩擦实验结果显示,微弧氧化处理使磨损率降低了近一个数量级,表明微弧氧化膜层具有良好的耐磨损性能;与牛骨的微动摩擦实验结果显示,微弧氧化陶瓷层的摩擦系数高于Ti6A14V,而且位移振幅越大摩擦系数越高,说明微弧氧化处理能有效阻止植入假体与骨组织之间的微动。     

TiAl合金微弧氧化膜的制备及抗氧化性能研究

利用微弧氧化的方法在γ-TiAl合金上制备陶瓷膜,探讨了氧化过程中电流密度与成膜速度的关系。利用扫描电镜研究了氧化膜的表面形态和截面结构,结果表明,氧化膜由三层组成,且氧化膜与基体间有良好的冶金结合;物相分析发现氧化膜中含有金红石、Al2TiO5和SiO2非晶成分,并且物相组成和分布与成膜时间及膜的深度无关;氧化膜的硬度随着氧化时间的增加而增加,极大值出现在距离膜基交界面约10μm附近的氧化膜中。1100℃下的高温氧化实验发现微弧氧化处理后样品的氧化速度只有原始基体材料的1／3,微弧氧化处理后提高了TiAl合金的抗氧化性。     

热处理温度对钛表面微纳米分级多孔膜结构特征影响规律

采用碱液处理医用钛表面制备出微纳米分级多孔结构膜层,通过酸处理以及不同温度热处理对微纳米分级多孔膜改性以提高其生物活性。利用SEM、EDS和XRD分析钛表面微纳米分级多孔膜的形貌、化学组成和物相组成,探讨热处理温度对钛表面微纳米分级多孔膜结构特征的影响规律。结果表明,当热处理温度低于750℃时,样品表面的微纳米分级多孔膜层形貌特征保持不变;当热处理温度为550℃时,钛表面微纳米分级多孔膜物相主要是结晶良好的锐钛矿型二氧化钛,具有良好的生物活性。     

Cytotoxicity of Ni from Surface-Treated Porous Nitinol (PNT) on Osteoblast Cells

The leaching of nickel from the surface of porous Nitinol (PNT) is mainly dependent on its surface characteristics, which can be controlled by appropriate surface treatments. In this investigation, PNT was subjected to two surface treatments, namely, water-boiling and dry-heating passivations. Phosphate buffer saline (PBS) solutions obtained from cyclic potentiodynamic polarization tests on PNT were employed to assess the cytotoxicity of Ni contained therein on osteoblast cells by Sulforhodamine B (SRB) assay. In addition, similar concentrations of Ni were added exogenously to cell culture media to determine cytotoxic effects on osteoblast cells. The morphologies of the untreated and the surface-treated PNTs were examined using SEM and AFM. Furthermore, growth of human osteoblast cells was observed on the PNT surfaces.     

多孔钛表面梯度磷灰石涂层的简单化学法制备

通过碱液处理或碱热处理并在模拟体液(SBF)中浸泡，在多孔钛表面制备了具有梯度结构的类骨磷灰石层。结果表明，碱液处理使多孔钛表面形成了网状多孔结构，组成为钛酸钠、金红石等。热处理后磷灰石在多孔钛表面的初期沉积更均匀。涂层中钙，磷、氧以及钛元素的含量随深度而变化，形成了梯度结构。具有表面梯度磷灰石涂层的多孔钛有望用于临床矫形，以提高种植体的生物活性和骨结合强度。     

热处理工艺对50钢超高周疲劳性能的影响

对50钢进行了正火 高温回火、中温回火、高温回火三种不同热处理状态的对称拉压超声疲劳试验,同时用扫描电子显微分析技术和X射线能谱分析方法对50钢的疲劳断口形貌进行显微分析,研究其疲劳断裂行为和疲劳断裂机理.结果表明,50钢存在表面和内部两种裂纹萌生机制;在本试验范围内,热处理工艺对50钢超高周疲劳性能的影响较低周和高周为小,随着寿命的增加,影响越来越弱;热处理工艺对50钢不同的疲劳阶段有不同的影响起源于不同的裂纹萌生机制,对常规疲劳性能起改善作用的热处理工艺可能对材料超高周疲劳性能的改善没有太大作用.     

The application of ultramicrotomy to the electronoptical examination of surface films on aluminium

Ultramicrotomy has been used to produce thin sections of surface films on aluminium after different treatments and these have been examined by transmission electron microscopy. Films studied are those produced by electropolishing, outdoor exposure, a hydrothermal treatment, immersion in sodium hydroxide, a chemical conversion process, an a.c. treatment and cathodic polarization. Anodic films including porous and barrier-type films and the thick coating on a superplastic ZnAl alloy have been examined. It has been found that the application of ultramicrotomy enables observation of the thickness and morphology of both very thin and friable surface films on aluminium, and it is useful in the study of certain phenomena concerning thicker porous-type anodic films. Various novel features are visible that have not been observed previously, and it is apparent that ultramicrotomy may be used advantageously to examine surface films on aluminium.     

多孔钛表面无裂纹生物活化层的制备及表征

采用碱热处理方法对多孔钛进行了表面活化处理,获得了无裂纹的网状微孔结构的生物活化层。利用扫描电镜(SEM)、X射线衍射仪(XRD)和X射线光电子能谱仪(XPS)等设备对生物活化层进行表征,最后用模拟体液中浸泡的方法检测了该活化层的生物活性。结果表明:当NaOH溶液浓度低于8 mol/L,碱处理时间少于36 h时,多孔钛孔内外壁都可获得无裂纹的生物活化层,该活化层呈现网状微孔结构,是由金红石结构的二氧化钛和钛酸钠组成的混合物质。浸泡SBF后结果显示该活化层在浸泡3 d后就已诱导产生了类骨的碳羟基磷灰石,表现出了很好的生物活性。     

A comparative study: The effect of surface treatments on the tribological properties of Ti-6Al-4V alloy

The effect of different surface treatments on the wear resistance of Ti-6Al-4V alloy has been investigated. For this purpose, plasma nitriding treatment was performed in a gas mixture 75% N₂-25% Ar, for 1 h treatment time and at 750 °C. The thin films were deposited using CFUMBS technique. The results showed that more surface roughness was obtained for nitrided specimens compared with thin film deposited specimens. It was also observed that both surface treatments improved the wear resistance of Ti-6Al-4V alloy. It was determined that plasma nitrided specimens exhibited excellent wear resistance compared with thin film deposited ones when applied load increased. Similar results were obtained from surface hardness measurements, and it was observed that load bearing capacity increased after plasma nitriding. The corrosion resistance of both surface treatments showed similar properties.     

Evaluation of anodic coatings on small decorative aluminium parts

A simple and rapid electrochemical method for the checking of the quality of anodic coatings on small decorative parts of aluminium is presented. This so-called ALU-buckle-test was developed and optimized for the quality control of anodized coloured and sealed buckles for watch bracelets. In the test the buckle is made the cathode in an electrochemical cell. The time it takes to reach a defined current density induced by an applied voltage, typically 1.6 V, is taken as the criterion of quality. The influence of different production conditions such as time of anodizing and time of sealing on the testing results has been studied. The results of the electrochemical test were observed to be affected by the quality of sealing, the coating thickness and the presence of flaws. It was found that this test provides an excellent criterion for the coating quality that correlates excellently with the well-known Alcoa test (ISO 3210) and a gravimetric method for the determination of the porosity of porous surface coatings.     

可控多孔结构生物活性钛的制备及其体外细胞培养

采用电子束熔化（EBM）成形工艺,制造具有可控多孔结构的Ti6Al4V植入体,分析测试其微观孔隙结构特征、孔隙率以及力学性能。扫描电镜观测结果表明,所制备的钛合金植入体孔隙结构特征与设计结构相符合,证明EBM技术能够实现钛合金植入体孔隙结构的控制;测得多孔植入体的孔隙率为60.1%,相应的抗压强度为163 MPa,弹性模量为14 GPa,与人体骨组织弹性模量相近。利用改进的碱热处理方法进行表面改性,并浸泡在模拟体液中以诱导磷灰石的形成。体外细胞培养试验结果表明,培养7 d后成骨细胞在改性的试件表面大量粘附、生长、增殖     

Effects of Microstructure on Corrosion of X70 Pipe Steel in an Alkaline Soil

Corrosion of X70 steel with different heat treatments (quenching, air cooling, and furnace cooling) in an alkaline soil was investigated by weight-loss, surface characterization and electrochemical measurements. The cathodic/anodic reactions of X70 steel in alkaline soil are dominated by the oxygen reduction and formation of iron oxides that deposit on the steel surface. The protection of the oxide deposit is through a physical block effect. The deposit layer formed on as-received steel has a compact, complete structure and thus, provides an effective protection over the underneath steel. However, the deposit layers on the heat-treated steels are generally loose, porous and defective, and provide minor protectiveness. Corrosion of steel is affected by its microstructure. Generally, steels with heat treatments have a higher corrosion rate than the as-received steel. The presence of more pearlite enhances the corrosion rate of ferrite by a galvanic effect. When the steel contains bainite and martenite phases, the activity of the steel is further increased.