Mg-4Zn合金表面掺锶羟基磷灰石涂层：物理化学性质及体外细胞响应

生物可降解镁合金由于具有高比强度、低弹性模量和优良生物相容性而受到广泛关注。然而,其过高的腐蚀速率却限制了其潜在的临床应用。因此,具有高生物相容性的羟基磷灰石(HA)涂层常被用于阻碍镁基体和周围生物环境的相互作用。采用电化学沉积法在Mg-4Zn合金表面制备了HA和掺锶(Sr)HA涂层。利用扫描电子显微镜(SEM)、能谱(EDS)、透射电子显微镜(TEM)、三维激光扫描显微镜(3D LSM)和亲水角监测系统对材料表面性质进行表征。本研究还探讨了材料动态离子释放、蛋白吸附、细胞吸附、增殖与成骨分化行为。结果显示,HA中引入Sr导致了晶格畸变和结晶度下降。涂覆掺SrHA的样品中镁离子释放量比其他样品更低,说明耐腐蚀性更好。掺Sr样品表面蛋白吸附与初始细胞吸附的改善是由于其具有更高的表面粗糙度和亲水性。Sr的引入并未显著改变细胞的增殖,却明显提高了成骨分化效果。综上所述,掺SrHA涂层是一种非常有前景的镁合金保护性生物相容涂层。     

Zinc-doped hydroxyapatite—zeolite/polycaprolactone composites coating on magnesium substrate for enhancing in-vitro corrosion and antibacterial performance

This work is focused on developing zinc-doped hydroxyapatite—zeolite (ZnHA—Zeo) and polycaprolactone (PCL) composite coatings on magnesium (Mg) substrate to improve the corrosion resistance and antimicrobial properties. Dip-coating technique was used to coat ZnHA—Zeo/PCL on the Mg substrate at room temperature. The samples were subjected to field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), energy dispersive X-ray spectroscopy (EDX) and antimicrobial potential. Results demonstrated that composite coatings consist of HA, scholzite, zeolite, and PCL phases. EDX spectra indicated the presence of calcium (Ca), silicon (Si), aluminum (Al), zinc (Zn), phosphorus (P) and oxygen (O). The composite surface appeared in spherical-like microstructure on coating with thickness ranging 226–260 μm. Zinc-doped HA—Zeo composite coating had a high corrosion resistance and provided sufficient protection to the Mg surface against galvanic corrosion. Doped ZnHA—Zeo coating samples exhibited superior disc inhibition by confirming antimicrobial activity against the E. coli as compared to HA—Zeo sample. Altogether these results showed that the ZnHA—Zeo coatings not only improved the corrosion resistance, but also enhanced the antimicrobial property and hence they can be used as suitable candidates for implant applications.     

Enhancing Biocompatibility and Corrosion Resistance of Ti-6Al-4V Alloy by Surface Modification Route

Titanium (Ti) and its alloys are widely used as candidate materials for biomedical implants. Despite their good biocompatibility and corrosion resistance, these materials suffer from corrosion after implantation in biological environments. The aim of this research work is to study the effect of two coatings on biocompatibility and corrosion behavior of Ti-6Al-4V biomedical implant material. Hydroxyapatite (HA) and hydroxyapatite/titanium dioxide (HA/TiO₂) coatings were thermal-sprayed on Ti-6Al-4V substrates. In the latter case, TiO₂ was used as a bond coat between the substrate and HA top coat. The corrosion behavior of coated and un-coated samples in Ringer’s solution was studied by potentiodynamic and linear polarization techniques. Before and after corrosion testing, XRD and SEM/EDS techniques were used for the analysis of phases formed and to investigate microstructure/compositional changes in the coated specimens. The cellular response was analyzed by the MTT (microculture tetrazolium) assay. The results showed that both the HA, as well as, the HA/TiO₂ coatings significantly increased the corrosion resistance of the substrate material. The HA coating was found to be more biocompatible as compared to the un-coated and HA/TiO₂-coated Ti-6Al-4V alloy.     

Interface activation and surface characteristics of Ti/TiN/HA coated sintered stainless steels

Interface activation and surface characteristics of Ti/TiN/HA film coated sintered stainless steels (SSS) have been investigated by electrochemical and biocompatibility tests. HA (hydroxyapatite), Ti, and Ti/TiN film coatings were applied using electron-beam deposition method (EB-PVD). Ti, Ti/TiN, and Ti/TiN/HA film coated surfaces and layers were investigated by SEM and XPS. The coated films showed micro-columnar structure, and Ti/TiN/HA films were denser than Ti or HA-only film. The corrosion resistance of the HA coating was similar to that of Ti/TiN/HA film coating when Cu content reached 4 wt.%, but the corrosion resistance of the HA coating decreased when Cu content increased from 4 wt.% in 0.9% NaCl solution. Therefore, HA-only coating could ensure corrosion resistance when Cu content does not exceed 4 wt.%. The results of biocompatibility tests of SSS on dogs showed that bone formation and biocompatibility were favorable when Cu content did not exceed 4 wt.%. The biocompatibility with bone was generally favorable in Ti/TiN/HA film coating and HA-only coating, while bone formation was somewhat faster for the HA film coated surface than for the Ti/TiN/HA film coating. Also, good cell growth and osseointegration without toxicity were observed.     

AZ31镁合金表面含纳米羟基磷灰石微弧氧化涂层的制备及性能研究

目的改善AZ31镁合金的耐腐蚀性能及生物活性。方法使用微弧氧化技术,分别在以六偏磷酸钠为主盐的电解液和以六偏磷酸钠为主盐、以纳米羟基磷灰石(HA)为添加剂的电解液中,在AZ31镁合金表面制备了微弧氧化涂层。通过扫描电子显微镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD)表征了涂层的微观形貌、元素特征和相组成。通过电化学方法和浸泡实验考察了涂层的耐蚀性。通过细胞实验评价了两种涂层的细胞相容性。结果电解液中的HA可以进入到微弧氧化涂层中,含HA的微弧氧化涂层较不含HA的更致密,且有封孔现象。电化学方法及浸泡实验结果表明,含HA的微弧氧化涂层的耐腐蚀性能更好。细胞表面粘附实验和细胞增殖实验也表明,经表面纳米HA微弧氧化处理后的AZ31镁合金生物相容性更好,且对MC3T3-E1细胞的增殖有促进作用。结论六偏磷酸钠电解液中添加纳米HA,可以在AZ31镁合金表面制备出含HA的微弧氧化涂层,且其耐腐蚀性能和生物活性均优于不含HA的微弧氧化膜。     

医用镁合金表面激光重熔羟基磷灰石涂层

为提高医用镁合金的表面耐蚀性和生物相容性,采用等离子喷涂和激光重熔复合技术在镁合金表面制备羟基磷灰石(HA)生物涂层。研究结果表明,所制备的羟基磷灰石涂层为短杆状堆积结构,主要由HA和β-TCP相组成;涂层的弹性模量约为50 GPa,较已临床应用的医用金属材料显著降低,显微硬度约为455 HV,具有较好的耐磨性。涂层在模拟体液中具有很好的耐蚀性,在腐蚀12 d后涂层表面形貌仍然较完整,无腐蚀孔洞出现。钙磷沉积实验结果表明,涂层表面形成一层新的生物磷灰石层,表明涂层具有较好的骨诱导性。     

电沉积制备氧化石墨烯-羟基磷灰石复合涂层

采用电沉积方法在钛表面制备氧化石墨烯-羟基磷灰石(Graphene oxide/Hydroxyapatite,GO/HA)复合涂层,通过调整GO的浓度,研究GO对所得涂层晶体结构及生物学性能的影响。采用扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)仪、傅里叶变换红外光谱(FTIR)、拉曼光谱分析所得涂层的表面形貌和物相构成,用SEM观察涂层表面MG63成骨样细胞生长情况。结果表明,电沉积法可在钛表面制备GO/HA复合涂层,且随GO浓度增加,HA结晶度增加。此外,复合涂层较单纯HA涂层更能促进成骨样细胞早期粘附。     

镁合金表面层层组装PSS/PAH膜诱导钙磷涂层

目的镁合金具有良好的生物相容性和可降解性,作为生物医用材料具有广泛的应用前景。有效地提高镁合金的耐蚀性能,对镁合金作为医用材料具有重要意义。方法利用浸泡法在AZ31镁合金基体表面层层组装制备聚苯乙烯磺酸钠(PSS)、聚丙烯胺盐酸盐(PAH)多层膜,并将获得的样品采用水热法在Ca(NO)_3、NaH_2PO_4、Na_2CO_3溶液中诱导钙磷涂层(羟基磷灰石)的形成。利用高分辨扫描电子显微镜、傅里叶红外光谱、X射线光电子能谱对Ca-P/(PAH/PSS)5/Mg复合膜层的表面形貌、化学成分进行了表征,通过析氢和电化学实验(包括极化曲线及阻抗谱)研究了Ca-P/(PAH/PSS)5/Mg涂层的耐腐蚀性能。结果Ca-P/(PAH/PSS)5/Mg膜层厚度约为7.67μm,表现为立体叶草状,在镁合金表面紧密排列。Ca-P/(PAH/PSS)5/Mg涂层耐蚀性提高一个数量级,其腐蚀电流密度从镁合金AZ31的3.69×10–5 A/cm2降低到1.61×10–6 A/cm~2,同时析氢速率降低。结论该涂层可以有效地提高镁合金的耐蚀性能,其成因则主要归功于组装的两种聚电解质的类生物矿化作用。这种诱导所得钙磷膜层对镁合金在生物医用领域的应用提供了新的思路。     

表面涂覆含氟羟基磷灰石和缺钙羟基磷灰石的镁合金体外降解行为(英文)

通过电化学沉积方法,在生物降解镁合金表面覆盖含氟羟基磷灰石(FHA)涂层和缺钙羟基磷灰石(CDHA)涂层。采用X射线衍射、傅立叶变换红外光谱、透射电子显微镜、扫描电子显微镜和能量色散X射线光谱研究涂层特性。结果表明:涂覆纳米FHA涂层的样品具有垂直于样品表面的纳米针状结构,比涂覆CDHA涂层样品的结构更致密和更均匀。纳米FHA涂层比纳米CDHA涂层具有更小的晶粒尺寸,分别为65 nm和95 nm。然而,CDHA涂层比FHA涂层更厚,厚度分别为19μm和15μm。通过极化、浸泡和析氢实验研究的腐蚀行为表明:纳米FHA涂层和纳米CDHA涂层显著降低腐蚀速率并引起钝化。纳米FHA和纳米CDHA涂层可以加速骨状磷灰石层的形成,相比未覆盖的镁合金可以显著减少溶出速率。纳米FHA涂层能对镁合金提供有效的防护并具有更高的腐蚀性能。因此,覆盖纳米FHA涂层的镁合金在整形外科领域具有良好的应用前景。     

甘油磷酸钙浓度对钛合金MAO涂层性能的影响

目的 提高医用钛合金的生物活性。方法 在含葡萄糖酸钙(Ca Glu₂)、葡萄糖酸镁(MgGlu₂)、植酸钠(Na₁₂Phy)和磷酸(H₃PO₄)的基本溶液中,分别添加8、10、12 g/L甘油磷酸钙(Ca-GP),采用MAO方法在Ti-6Al-4V表面制备3种涂层。使用SEM、EDS、XRD、XPS和AFM检测涂层表面形貌、化学成分、物相结构、元素存在状态和表面粗糙度,并测试涂层的接触角、结合强度以及体外生物活性。结果 经过MAO处理后,钛合金表面可成功生长出多孔陶瓷涂层,Ca-GP参与了MAO涂层形成。当Ca-GP的质量浓度为8 g/L时,涂层非常粗糙,Ca和Mg的原子数分数分别为7.56%和1.74%。随着Ca-GP浓度的增加,微孔均匀性变好,表面微裂纹减少,且钙磷原子比(Ca/P)显著提高。在含8、10 g/L的Ca-GP溶液中,制备的涂层以Ti、锐钛矿和金红石型Ti O2组成为主;在12g/L的Ca-GP溶液中生成的涂层,Ca/P原子比可达1.77,含有Ti P     

Characterization, Corrosion Resistance, and Cell Response of High-Velocity Flame-Sprayed HA and HA/TiO2 Coatings on 316L SS

The main aim of this study is to evaluate corrosion and biocompatibility behavior of thermal spray hydroxyapatite (HA) and hydroxyapatite/titania bond (HA/TiO₂)-coated 316L stainless steel (316L SS). In HA/TiO₂ coatings, TiO₂ was used as a bond coat between HA top coat and 316L SS substrate. The coatings were characterized by x-ray diffraction and scanning electron microscopy/energy dispersive spectroscopy, and corrosion resistance determined for the uncoated substrate and the two coatings. The biological behavior was investigated by the cell culture studies using osteosarcoma cell line KHOS-NP (R-970-5). The corrosion resistance of the steel was found to increase after the deposition of the HA and HA/TiO₂ bond coatings. Both HA, as well as, HA/TiO₂ coatings exhibit excellent bond strength of 49 and 47?MPa, respectively. The cell culture studies showed that HA-coated 316L SS specimens appeared more biocompatible than the uncoated and HA/TiO₂-coated 316L SS specimens.     

淫羊藿苷含量对Mg/UMAO/CS/IC涂层性能的影响

为了研究淫羊藿苷含量对镁/超声微弧氧化/壳聚糖/淫羊藿苷（Mg/UMAO/CS/IC）涂层性能的影响,并提高纯镁的耐蚀性,采用电泳沉积（EPD）和UMAO技术在纯镁基体上制备Mg/UMAO/CS/IC涂层。采用扫描电子显微镜（SEM）、X射线衍射（XRD）、原子力显微镜（AFM）和傅立叶变换红外光谱（FTIR）对涂层的特征进行分析。对不同样品在模拟体液中进行了电化学阻抗和动电位极化的腐蚀行为研究。结果表明：当IC含量为0.4 g/L时CS/IC层具有较好的封孔效果。添加不同IC含量的Mg/UMAO/CS/IC涂层均由Mg、MgO、CS和Mg₂SiO₄组成。不同IC含量涂层的自腐蚀电流密度（i_corr）比Mg至少都低一个数量级,能为镁基底提供更有效的保护。IC含量为0.4 g/L时Mg/UMAO/CS/IC涂层的耐蚀性更好,自腐蚀电流密度（1.667×10^-6 A/cm²）最小。Mg/UMAO/CS/IC涂层可有效解决纯镁在临床骨内固定应用上降解过快的问题。     

不同镁合金支架材料MAO/PLLA复合膜研究

两种系列的镁合金WE42与AM20微弧氧化(MAO)后用浸渍法对微弧氧化膜进行聚乳酸(PLLA)封孔处理制备复合涂层,通过扫描电镜(SEM)分析微弧氧化膜及聚乳酸封孔膜的表面形貌及结构,X射线衍射(XRD)分析微弧氧化膜的主要成分为MgSiO3和SiO2,通过腐蚀失重测定试样的失重率.在37℃的hank's模拟体液中测...     

铝基非晶纳米晶复合涂层研究

采用自动化高速电弧喷涂系统,用自行研制的粉芯丝材,在AZ91镁合金基体表面上制备出Al-Ni-Y-Co非晶纳米晶复合涂层.采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、透射电子显微镜(TEM)分析了Al-Ni-Y-Co非晶纳米晶复合涂层的微观形貌和组织结构,结果表明Al-Ni-Y-Co非晶纳米晶复合涂层是由非晶相和纳米晶化相共同组成的,涂层结构致密,孔隙率约为1.8%.Al-Ni-Y-Co非晶纳米晶复合涂层的平均显微Vickers硬度值为311.7 HV0 1,结合强度为26.8 MPa.涂层的抗磨损耐腐蚀性能优于Al涂层和AZ91镁合金基体;其相对耐磨性约为Al涂层的10倍,为AZ91镁合金的6倍;其自腐蚀电位值正于Al涂层及AZ91镁合金,自腐蚀电流密度值约为Al涂层的1/2,AZ91镁合金的1/5;其腐蚀后的表面形貌比Al涂层和AZ91镁合金平整,点蚀较少.Al-Ni-Y-Co非晶纳米晶复合涂层的耐磨防腐综合性能优异.     

Functionally graded carbon nanotubes/hydroxyapatite composite coating by laser cladding

Functionally graded carbon nanotubes/hydroxyapatite (CNTs/HA) composite coatings have been fabricated by laser cladding technique using CNTs/HA composite powders. As the feedstock for laser deposition, CNTs/HA composite powders were prepared by ball-milling different weight ratios (1%, 3% and 5%) of CNTs with HA powders. CNTs/HA composite coatings were fabricated with CNTs/HA composite powders and functionally graded coating was fabricated by sequentially depositing different CNTs/HA composite coatings on pure titanium. The phase composition, microstructure, micro-hardness, bonding strength and in vitro cellular responses of the composite coatings and the functionally graded composite coating were studied. The results show that the crystallinity of CNTs/HA composite coatings increased with increasing amount of CNTs in the powder mixture. The CNTs were dispersed homogeneously in the coatings to form an interconnected web and the cylinder graphic structure of CNTs was not changed after laser irradiation. Compared with pure HA coating, the maximum increase of the micro-hardness of CNTs/HA composite coatings was 46.8% and the micro-hardness of the functionally graded coating increased gradually through the thickness of this coating. Furthermore, the bonding strength of the functionally graded coating was nearly twice higher than that of pure HA coating. The in vitro cellular biocompatibility tests reveal that the functionally graded composite coating has comparable in vitro bioactivity with pure HA coating.     

掺杂镍对镁合金表面冷喷涂锌基涂层性能的影响

目的研究镍添加对冷喷涂锌基涂层耐蚀性的影响,为镁合金提供有效的防护涂层。方法采用低压冷喷涂技术在镁合金基体表面分别制备锌基和锌/镍基复合涂层,通过微观观察、摩擦磨损实验、电化学极化法和电化学阻抗谱测试及全浸泡腐蚀试验,研究镁合金表面冷喷涂涂层的结构、摩擦磨损行为和耐蚀性。结果镁合金表面冷喷涂锌基涂层后,其硬度和耐磨性得到显著提高,掺镍后的锌/镍基涂层具有更高的硬度和耐磨性。锌基和锌/镍基涂层均能为镁合金提供腐蚀防护,锌/镍基涂层比锌基涂层具有更好的耐蚀性。相对镁合金来说,锌基涂层和锌/镍基涂层的自腐蚀电位分别正移了260 mV和560 mV;长期腐蚀后锌/镍基涂层形成了更致密的腐蚀产物膜,腐蚀电阻显著高于锌基涂层。结论冷喷涂锌基和锌/镍复合涂层均能对镁合金提供防护作用,掺杂镍后的锌/镍基复合涂层具有更高的硬度、耐磨性和耐蚀性。     

Microstructure and corrosion behaviour of arc sprayed Zn–Al–Mg–RE cathodic protection coatings on steel substrates

Abstract

Cored wires and high velocity arc spraying technologies have been used to produce Zn–Al–Mg and Zn–Al–Mg–RE (where RE is rare earth) coatings on A3 steel. The durability of coatings in terms of corrosion resistance is the focus of this paper. To study the effect of RE, Zn–Al–Mg coatings also have been produced as a comparison. The microstructures of original coatings and corroded coatings have been investigated after corrosion tests by SEM and XRD. The potentiodynamic polarisation and electrochemical impedance spectroscopy techniques were carried out to determine the corrosion behaviour of the two coatings in 5% NaCl solution. Metallographic as well as electrochemical corrosion results illustrate that the coatings possess a self-sealing capacity, and that the corrosion products can refine the microstructure and enhance the corrosion resistance. Compared to the Zn–Al–Mg coating, the Zn–Al–Mg–RE coating presents a more obvious and stable self-sealing process.     

Surface morphology and in vitro bioactivity of biocompatible hydroxyapatite coatings on medical grade S31254 steel by RF magnetron sputtering deposition

Hydroxyapatite (HA) is popularly used as a biocompatible coating material for metallic implants, in view of its improved bone fixation property, leading to an increased life of the implant. However, the deposition of HA on medical grade UNS S31254 stainless steel (SS254) for orthopaedic implant applications by the radio-frequency magnetron sputtering technique is unreported in the literature so far. The surface morphology of the deposited HA coatings was characterised using scanning electron microscopy and atomic force microscopy, while their phase composition was determined using X-ray diffraction. The thickness and adhesive strength of the HA coatings were determined using an ellipsometer and a tensometer, respectively. Finally, the antibacterial efficacy and bioactivity of the deposited coatings were confirmed using fluorescence activated cell sorting and immersion testing in simulated body fluid environment. The results obtained showed that the HA coatings grown on SS254 using magnetron sputtering possess desirable surface properties as well as good adhesion and biocompatibility properties, ideally suited for potential applications in orthopaedic implants.     

工艺参数对电沉积制备铝镁合金的影响

目的以AlCl_3和LiAlH_4为溶质,苯和四氢呋喃为溶剂,进行电沉积铝镁合金,探索制备铝镁合金的最佳工艺条件。方法在AlCl_3-LiAlH_4-苯-四氢呋喃体系中,采用镁作阳极,通过预电沉积获得一定浓度的Mg~(2+),从而进行电沉积制备铝镁合金镀层。改变电流密度、沉积时间、预电沉积时间和预电沉积次数等参数,以探究工艺参数对铝镁镀层的形貌、晶粒大小和镁含量的影响,并通过SEM和EDS检测和分析铝镁合金的镀层形貌、成分及含量。结果镀层主要成分为Al_3Mg_2和Al_(12)Mg_(17),当电流密度为16.67 m A/cm~2时,获得的镀层表面效果最好,其晶粒尺寸可达1~2mm。预电沉积次数越多,通过预电沉积获得的Mg~(2+)越多,铝镁合金镀层中镁的含量越高,最高可达2.93%(质量分数)。结论在一定范围内,镀层中的镁含量随预电沉积时间的增加而提高。预电沉积次数越多,通过预电沉积溶解的Mg~(2+)越多,铝镁合金镀层中的镁含量越高。当沉积时间过长时,不利于镀层中镁含量的提高。铝镁镀层中的镁含量越高,电化学阻抗越大,腐蚀电位越大,镀层的耐腐蚀性能越好。     

Mg含量对热浸镀Al-Zn-Mg-Si镀层组织及性能的影响

为了提高冷轧镀铝锌钢板表面晶花质量,在连续热浸镀生产线制备了4种不同成分的Al-Zn-Mg-Si镀层样板,采用体视显微镜、扫描电镜、电子探针、X射线衍射仪和电子背散射衍射等方法,研究了Mg含量对镀层凝固组织和耐腐蚀性能的影响。结果表明:随Mg含量的增加,镀层晶花尺寸先减小后增大,耐腐蚀性先降低后增高;在Mg质量分数为1.0%时,镀层质量最佳,晶花细小均匀,平均晶粒尺寸为1.2 mm,镀层截面组织中含质量分数为68.3%的富铝相、质量分数为26.1%的富锌相、少量富硅相和富镁相,在60 d内的平均失重速率为0.05 g/(m²·d)。