微束等离子喷涂制备羟基磷灰石涂层微观结构的特征研究

目的 通过与大气等离子喷涂和超音速火焰啧涂的对比,研究微束等离子喷涂制备的羟基磷灰石涂层的微观组织特点.方法 以高结晶度的羟基磷灰石粉末为原料,采用三种不同的喷涂方法(微束等离子喷涂、大气等离子喷涂和超音速火焰喷涂),在Ti-6Al-4V基体上制备羟基磷灰石(HA)涂层.利用冷场发射扫描电子显微镜和X射线衍射仪,对三种涂层的形貌、相组成和择优取向进行分析.结果 与大气等离子喷涂及超音速火焰喷涂制备的涂层相比,应用该设备制备的羟基磷灰石涂层表面平整致密,无大量的气孔存在;涂层截面呈典型的层状结构,在近三分之一表面处观察到柱状晶;涂层中仅有少量的非晶相及分解相,结晶度高达90％以上.这些特征均有利于羟基磷灰石涂层在体液环境中的稳定性.结论 比较三种喷涂方法,采用微束等离子喷涂制备的羟基磷灰石涂层致密,结晶度高,杂相少,且存在择优取向的柱状晶.     

微束等离子喷涂羟基磷灰石涂层的体外生物活性研究

采用微束等离子喷涂(MPS)方法在Ti6A14V基体上制备羟基磷灰石(HA)涂层.利用扫描电镜(SEM)和x射线衍射(XRD)分析技术对HA涂层的表面形貌、相组成和结晶度进行表征,并通过模拟体液进行体外生物活性试验.结果表明,微束等离子喷涂制备的HA涂层具有一定粗糙度,存在气孔以及微裂纹.涂层存在热分解现象,涂层中含有HA、α-TCP、β-TCP和非晶相,不含CaO等杂质相.模拟体液试验表明,微束等离子喷涂工艺制备的HA涂层具有较好的生物活性和稳定性.涂层表面均有较大比例的CaP沉积层,且涂层整体保持完整,没有出现明显的剥离.     

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.     

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.     

等离子喷涂HA/(HA+TiO2)复合生物涂层的研究

用X射线衍射仪(XRD)、电子探针(EPMA)等检测手段，以大气等离子喷涂法在纯钛表面制备的羟基磷灰石HA／(HA TiO2)复合涂层及其热处理为研究对象，探讨了TiO2在羟基磷灰石复合涂层中的作用。结果表明，喷涂后的(HA TiO2)过渡层中交替分布的HA和TiO2结合致密；HA／(HA TiO2)涂层表面裂纹比对应纯HA涂层的细小，涂层内部结合致密，证实TiO2的加入具有缓和应力的作用。     

微束等离子喷涂气体对HA涂层结晶度的影响

采用微束等离子喷涂方法,分别选用工业纯氩气和含50%氦气的氦氩混合气体为工作气体,在Ti-6Al-4V基体上制备羟基磷灰石涂层.通过SEM和XRD对涂层形貌、相组成和结晶度进行研究.结果表明,两种工作气体均可以制备杂质相含量少且不产生TTCP(磷酸四钙)和CaO等杂质相的涂层,结晶度高于70%,对植入体在体内的稳定性有利.采用氦氩混合气体为工作气体的微束等离子弧热焓值高于氩气工作气体,前者涂层中的结晶相主要以再结晶的为主,后者结晶相以大量未熔HA内核为主.     

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.     

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。     

水蒸气处理对钛合金表面羟基磷灰石涂层结构的影响

目的 制备结晶度较高且裂纹较少的羟基磷灰石涂层。方法 采用等离子喷涂法,在不同功率下,于钛合金表面制备羟基磷灰石涂层。通过水蒸气处理法,在不同温度下处理羟基磷灰石涂层。使用扫描电子显微镜（SEM）和X射线衍射仪（XRD）分析羟基磷灰石的表面形貌和晶体结构。结果 当等离子喷涂功率从20 kW增大到29 kW时,羟基磷灰石涂层的沉积效率先增大后稳定,涂层结晶度先增大后减小,涂层中氧化钙的含量先增大后稳定。当喷涂功率为23 kW时,羟基磷灰石涂层结晶度较高。水蒸气处理能明显去除涂层中的α-磷酸三钙、β-磷酸三钙和氧化钙,当水蒸气处理温度从140 ℃增大到200 ℃时,羟基磷灰石涂层晶粒由棒状向颗粒状转变,涂层结晶度不断增大,涂层中磷酸四钙的含量先减小后增大,较高的温度会造成涂层表面微裂纹的产生。在模拟体液中浸泡后,经过水蒸气处理的涂层表面会诱导生成较纯的羟基磷灰石。180 ℃水蒸气处理后的涂层表面会沉积一层均匀的羟基磷灰石,生物活性较高。结论 羟基磷灰石涂层的结晶度随等离子喷涂功率的增大,先增大后减小,随水蒸气处理温度的上升而增大。在合适条件下制得的羟基磷灰石涂层具有较高的生物活性。     

羟基磷灰石涂层及其热处理对TLM合金基体的影响

利用DTA/TG、XRD方法研究溶胶凝胶法制备羟基磷灰石(HA)烧结热处理过程中的相转变规律,同时研究制备HA涂层时保温处理对TLM(TiZrSnMoNb系)合金基体力学性能的影响.结果表明,在制备HA涂层的过程中.热处理温度为450～1000℃,所得的HA的晶化程度较高,较纯净.     

Electrophoretic deposition of bioactive glass/polymer composite coatings with and without HA nanoparticle inclusions for biomedical applications

Electrophoretic deposition (EPD) methods have been developed for the fabrication of composite bioactive glass–hydroxyapatite (HA)–chitosan and bioactive glass–HA–alginate composite coatings. Two different strategies have been utilized, which are based on the use of cationic chitosan and anionic alginate biopolymers. The mechanism of cathodic deposition of chitosan is based on the pH increase at the cathode surface, whereas the pH decrease at the anode surface enabled the deposition of alginate coatings. The use of chitosan and alginate enabled the electrosteric stabilization and deposition of bioactive glass and HA particles. Composite coatings were obtained on various conductive substrates and studied by thermogravimetric analysis (TGA), differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The composition of the coatings can be varied by variation of bioactive glass and HA concentrations in the suspensions. The proposed method offers the advantages of room temperature fabrication of bioactive composite coatings that are suitable for biomedical applications.     

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。     

Hydroxyapatite coating on pretreated CoNiCrMo prosthesis

1 INTRODUCTIONCo-alloys arei mportant metallic medical mate-rials for tribologically loaded knee , hip joints andtheir fixation parts ,as shownin Fig.1 ,due to ex-cellent mechanical , tribological and corrosion-resistant properties[1]. A bioactive ceramic coat-ings ,especially hydroxyapatite( HA) coating, onmetallic prostheses is a promising approachfor i m-proving its osteoconductivity and bone-bondingability[2 11]. Nowadays ,some plasma sprayed HAand other bioceramic coatings on metall…     

低压沉积-微弧氧化制备钛金属HA-TiO2复合膜层

采用低压沉积-微弧氧化法,在钛金属表面直接制备了具有生物活性的HA-TiO2复合膜层,通过XRD和SEM分别分析了膜层的相结构和表面形貌,探讨了沉积参数对膜层中HA含量与表面形貌的影响.结果表明:低压沉积处理是微弧氧化法制备HA-TiO2复合膜层的必要条件;复合膜层主要由金红石型和锐钛矿型TiO2及HA组成,HA以白色...     

钛合金表面GO/HA/MAO复合膜层的制备及其性能

为了改善钛合金种植体在体液中的腐蚀及摩擦腐蚀行为,延长其在人体环境中的服役时间,在微弧氧化 (MAO)膜层上采用溶胶凝胶(Sol-gel)法于羟基磷灰石(HA)和氧化石墨烯(GO)的混合溶胶中浸渍提拉成膜,从而在 Ti6Al4V 合金表面成功地制备了 GO/ HA/ MAO 复合膜层。 结果表明,MAO 膜层表面的微孔及微球被 GO/ HA 薄膜有效的覆盖且较为致密;膜层的物相组成主要为金红石相及锐钛矿相的 TiO₂、HA、SiO₂ 和GO;根据电化学腐蚀和摩擦腐蚀结果分析知,GO/ HA/ MAO 复合膜层在模拟体液(SBF)中的耐蚀性及耐摩擦腐蚀性相比于 MAO 膜层和 Ti6Al4V 基体均得到了显著提高。     

Deposition, Characterization, and Enhanced Adherence of Escherichia coli Bacteria on Flame-Sprayed Photocatalytic Titania-Hydroxyapatite Coatings

Nanostructured titania has been extensively investigated as photocatalytic material and is capable of killing bacteria attached on its surface. The persistent challenge yet is how to effectively promote adhesion of bacteria on its surface for consequent extermination. The study presented here deals with liquid flame-sprayed nanostructured titania-hydroxyapatite (HA) coatings. Addition of HA alleviated phase transformation of titania from anatase to rutile during the coating deposition, reducing rutile to anatase ratio from 9.58 to 1.99%, and precluded effectively aggregation of the nano titania particles in the as-sprayed coatings. Adherence of Escherichia coli bacteria on the coatings showed significant dependence on content of HA, and the increased HA content resulted in enhanced attachment of the bacteria. Examination of the photocatalytic activity of the coatings through decomposition of methylene blue dye in water revealed that addition of HA did not markedly deteriorate the photocatalytic performances of the coatings. The coatings consisting of 10 wt.% HA showed the best photocatalytic activity, which is comparable to that exhibited by immobilized Degussa P25 coatings. The unambiguous evidence provided in this study suggests that the coatings made from combination of biocompatible HA and photocatalytic nano titania have great potential for antibacterium applications.     

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.     

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.     

钛基材上电化学沉积羟基磷灰石

通过电沉积法在经过阳极氧化的钛基材表面沉积磷酸钙盐涂层,再经碱热处理使磷酸钙涂层转变为羟基磷灰石涂层。扫描电镜(SEM)观察了阳极氧化后生成的TiO2纳米管的微观结构,以及生成的羟基磷灰石的形貌。X射线衍射仪(XRD)分析了涂层的相组成,同时测定了涂层与基体的结合强度。试验结果表明:电沉积涂层CaHPO4·2H2O经碱处理后转变为羟基磷灰石;电沉积添加双氧水与钛基材经过阳极氧化后使得涂层与基体结合强度有所提高。模拟体液浸泡试验表明涂层具有良好的生物活性。