用磁控溅射技术制备钛合金表面HA生物涂层

目的探讨磁控溅射法制备的HA生物涂层组织结构以及涂层与基体的界面结合性能. 方法利用射频磁控溅射技术在Ti-6Al-4V基体表面制备HA生物涂层,利用扫描电镜(SEM)观察HA生物涂层表面形貌和断面形貌,利用X射线衍射仪(XRD)分析涂层的相结构,利用能量分散谱仪(EDS)分析涂层的Ca/P比,采用环氧树脂E-7对接法测定HA涂层与基体的界面结合强度. 结果溅射HA生物涂层的Ca/P比为1.7, 后处理生物涂层中不存在其它钙磷杂质相,HA的晶化程度高,HA涂层与基体的界面结合强度为51.2MPa. 结论射频磁控溅射技术制备的HA生物涂层,表面形貌良好,涂层与基体的界面结合强度较高.     

磁控溅射制备HA/Ti6Al4V复合材料种植体体外生物活性研究

研究了射频磁控溅射法制备的HA/Ti6Al4V复合材料种植体在模拟体液(Simulated body fluid,SBF)环境下的生物活性。利用扫描电镜(SEM)、能谱分析(EDS)、红外光谱(FTIR)及X-射线衍射(XRD)分析了该种植体涂层在模拟体液中浸泡前后的表面形貌、界面结合状态、晶体结构和相组成的变化,结果表明:该种植体涂层在模拟体液中存在溶解和新生物质在其表面沉积相伴的过程。其中,HA涂层表面的新生物质是一种缺钙型且含有CO32-的类骨磷灰石,其n(Ca)/n(P)比值约为1.56,晶粒小,结晶度低,接近于非晶态,这与自然骨中无机相的结构成分相似,因此具有良好生物相容性和生物活性。     

电沉积HA-Ti/HA复合涂层及其生物学性能

为了提高HA涂层的结合强度，采用两步电沉积法制备HA—Ti／HA复合涂层，对涂层的组分结构、表面形貌和结合强度进行了研究，并对涂层进行模拟体液和体外细胞实验，以考察涂层的生物学性能。实验结果表明：HA—Ti／HA复合涂层的结合强度明显高于HA涂层，当涂层中Ti的质量分数为51．2wt％时，涂层与基体的结合强度达到21．2MPa，约为纯HA涂层的3倍。涂层经模拟体液浸泡后，表面覆盖一层碳磷灰石（Carbonate—apatite），表明涂层具有良好的生物活性。体外细胞实验表明，骨髓基质细胞能在涂层表面黏附繁殖生长，表明涂层具有良好的生物相容性。     

HA（＋ZrO2＋Y2O3）／Ti6Al4V复合涂层的微结构与生物活性

采用射频磁控溅射法成功制备了HA（＋ZrO2＋Y2O3）／Ti6Al4V生物复合涂层。借助于XRD、SEM、FTIR及AFM等对溅射涂层的相组成、微观形貌和界面结合进行了研究，并以模拟体液试验探讨了涂层的生物活性。实验结果表明：磁控溅射的复合涂层呈非晶态，经过退火处理，可以使其完全转化为晶态；复合涂层的微观表面凹凸不平，并呈现网状结构和较多的孔隙，其孔隙直径约为0．5μm-2μm；涂层的生长模式为层状加岛状生长；复合涂层在模拟体液中浸泡一段时间后，表面覆盖一层新生物质——含有CO^2-3的类骨磷灰石，其晶粒非常小，它与自然骨中无机相的结构成份相似．因此复合涂层具有良好生物相容性和生物活性。     

HAF/YSZ梯度复合涂层的制备及结构和性能

背景：在钛合金基体表面制备涂层的方法多为等离子喷涂法、溶胶-凝胶法、离子束溅射法等,所制备的涂层性能不稳定、成分单一,且涂层物相组成较难控制。 目的：采用射频磁控溅射技术在Ti6Al4V基体上制备含氟羟基磷灰石梯度复合涂层HAF/YSZ。 方法：在Ti6Al4V基体上以射频磁控溅射技术制备含氟羟基磷灰石梯度复合涂层HAF/YSZ,利用X射线光电子能谱、扫描电镜等对涂层的成分分布、形貌、界面结合进行表征。通过模拟体液实验分析和评价HAF/YSZ涂层、HAF1.2涂层及羟基磷灰石涂层的生物性能。 结果与结论：所制备的HAF/YSZ梯度涂层表面粗糙,呈多孔岛状结构,有利于新生骨组织生长;涂层与基体结合紧密,各层间相互扩散,整体一致性较好;经模拟体液浸泡后,涂层表面有新生物质沉积,表现出较好的生物活性及稳定性,且梯度复合涂层较氟含量单一的氟羟基磷灰石涂层具有更好的抗体液溶解能力及稳定性。     

碳/碳复合材料表面羟基磷灰石涂层的研究

采用等离子喷涂技术在碳／碳复合材料上制备了羟基磷灰石（HA）涂层，用扫描电镜（SEM）观察了涂层的微观结构．用X射线衍射仪（XRD）分析了涂层的相组成，并测定了涂层与基体的结合强度。结果表明：在碳／碳基体表面获得了具有一定粗糙度的羟基磷灰石涂层；在等离子喷涂过程中，发生了羟基磷灰石的非晶化现象，经过热处理后可转变为晶相；涂层与基体的剪切强度为7.15MPa。     

HA(+ZrO2+Y2O3)/Ti6A14V复合涂层的微结构与生物活性

采用射频磁控溅射法成功制备了HA(+ZrO2+Y3O3)/Ti6A14V生物复合涂层.借助于XRD、SEM、FTIR及AFM等对溅射涂层的相组成、微观形貌和界面结合进行了研究,并以模拟体液试验探讨了涂层的生物活性.实验结果表明磁控溅射的复合涂层呈非晶态,经过退火处理,可以使其完全转化为晶态;复合涂层的微观表面凹凸不平,并呈现网状结构和较多的孔隙,其孔隙直径约为0.5 μm～2 μm;涂层的生长模式为层状加岛状生长;复合涂层在模拟体液中浸泡一段时间后,表面覆盖一层新生物质--含有CO32-的类骨磷灰石,其晶粒非常小,它与自然骨中无机相的结构成份相似,因此复合涂层具有良好生物相容性和生物活性.     

稀土在激光涂覆生物陶瓷涂层中的行为与分布

在金属基材上利用等离子喷涂、焙烧等技术获得金属-生物活性陶瓷表面复合材料,因既具金属的强度、韧性,又具表面生物陶瓷良好的生物活性,故成为硬组织植入材料而受到极大关注[1]。但众所周知,等离子喷涂生物陶瓷涂层与基体的界面结合以机械咬合为主,且组织形貌与活体硬组织相差很大,它必然影响植入材料的生物相容性及其寿命。本课题组利用稀土的掺杂,在钛合金基材上,用激光涂覆工艺成功地获得含羟基磷灰石(HA)的钙磷基生物陶瓷涂层[2],不仅使HA等的合成与涂覆同步形成,简化了工艺,且涂层与基体的结合为化学冶金结合。而稀土的掺杂,对金属…     

射频磁控溅射法制备羟基磷灰石/β-磷酸三钙生物涂层

目的以粉末冶金烧成的羟基磷灰石(HA)/-β磷酸三钙(β-TCP)陶瓷为靶材,采用磁控溅射法在钛合金(Ti6Al4V)基体上制备HA/β-TCP生物涂层。方法利用XRD研究了复合涂层的晶化程度,讨论了涂层成分与生物降解性及相容性的关系。结果HA/β-TCP生物涂层为非晶态,经700℃,3h大气处理可显著提高涂层的晶化程度,当涂层成分为50wt%HA/50wt%β-TCP时其细胞相容性最好。结论在钛合金基体上制备HA/β-TCP生物涂层,通过HA与β-TCP的复合来控制材料的降解速度,使它的降解速度与周围骨组织的生长速度相匹配,使植入体具有良好的生物降解性、生物活性和力学性能。     

一种碳/碳复合材料表面制备高结合强度羟基磷灰石涂层的新方法

背景：目前在碳/碳表面制备羟基磷灰石涂层的方法有很多种,但所制涂层与基体的结合强度不高。 目的：提出一种在碳/碳复合材料表面制备高结合强度羟基磷灰石涂层的新方法。 方法：首先利用感应加热法在基体表面制备出无水磷酸氢钙涂层,而后对其进行水热处理,转变为羟基磷灰石相。扫描电镜观察涂层的形貌,划痕法测试涂层的临界载荷,顶出法测试剪切强度。 结果与结论：感应热沉积法可以在碳/碳复合材料表面制备出致密的块状晶粒结构的无水磷酸氢钙涂层;通过水热处理可以将其转变成结晶完好致密的羟基磷灰石涂层。涂层的临界载荷为13.31 N,剪切强度约为47 MPa。     

Mechanical properties of a dental ceramic coated by RF magnetron sputtering

Metal and ceramic thin film coatings were deposited onto a dental ceramic via radio frequency (RF) magnetron sputtering. The objectives of the study were to determine if a coherent interface could be produced between the coating and the substrate and if the coating significantly would improve the mechanical properties of the ceramic. Thin films of Au, Al, and AlN were deposited in this study. Mechanical testing results indicated that a significant improvement in flexural strength was observed with both Au and Al coatings while significant improvements in the flexural modulus were observed with all three materials. SEM analysis indicated that the interfaces were coherent and also suggested two mechanisms (crack bridging and crack blunting) that could be responsible for the enhanced mechanical properties.     

Characterization of hydroxyapatite and titanium coatings sputtered on Ti-6Al-4V substrate.

A series of thin (<10 microm), single-layered HA/Ti coatings were deposited on Ti-6Al-4V substrate using a radio frequency magnetron-assisted sputtering system. The adhesion strength, microstructure, and chemistry of the coatings were characterized. Experimental results showed that higher Ti contents in targets or coatings resulted in higher deposition rates. When Ti was added the highly crystalline structure of monolithic HA coating was largely disrupted and the coating became amorphous-like. The highly crystalline structure of the monolithic Ti coating was also disrupted by introducing small amounts of Ca, P, and O into the coating. The HA/Ti coatings had quite uniform thicknesses and appeared smooth, dense, and well bonded to the substrate. A scanning electron microscope with an energy dispersive spectroscopy system showed that monolithic HA, 95HA/5Ti, 25HA/75Ti, and 50HA/50Ti coatings had the lowest Ca/P ratios while the 75HA/25Ti coating had the highest. The adhesion strengths of all coatings were between 60 and 80 MPa.     

Crystal chemistry of hydroxyapatite deposited on titanium by sputtering technique

Crystalline hydroxyapatite (HA) powder was coated on titanium substrate by radio frequency (RF) magnetron sputtering. The coating was homogeneous thin film and the thickness was 1microm. Crystallinity of the HA coating was low and Ca/P ratio was high as 3.0. Particle sizes were 40 to approximately 100 nm, and the crystallite size was calculated by 30 to approximately 50 nm using an X-ray diffractometry (XRD) and a transmission electron microscopy (TEM). When the coating was heated at 800 degrees C for 1 h, the low crystalline HA grew up crystalline HA, and a diffraction pattern of CaO appeared. When the coating was immersed in pH 7.4 of bovine serum for 1 week, c-axis of HA increased.     

Hydroxyapatite thin films deposited onto uncoated and (Ti,Al, V)N-coated Ti alloys.

Plasma-sputtered hydroxyapatite (HA) thin coatings ( approximately 1 microm) were deposited onto uncoated and (TiAlV)N-coated Ti-6Al-4V-alloy substrates at low temperatures. The (TiAlV)N coating interlayer was deposited by reactive sputtering. Depositions were achieved by utilizing unbalanced and balanced magnetrons in a capacitively coupled RF plasma. Characterization of the thermostability, bioerosion resistance, and chemical composition of the coating layer was examined by scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), and Fourier transform infrared spectroscopy (FTIR). The results show that for deposition temperatures as low as 67 degrees C, the crystalline phase of the HA coating still is clearly detectable and that the underlying (TiAlV)N coating can increase the crystallinity and thermostability of the HA coating before and after heat treatment. The thin ( approximately 1 microm) sputtered HA coating shows strong HA characteristic peaks in the FTIR spectra even after a 30-day dissolution test. The experimental results show that a multilayer structure comprised of a bioinert (TiAlV)N and bioactive HA coating has the potential to improve the biocompatibility of implant materials. The bioinert (TiAlV)N coating also may provide a long-term stable interface between bone tissue and an alloy implant after the bioactive HA coating is remodeled by the surrounding tissue.     

Effect of substrate temperature on mechanical properties of calcium phosphate coatings

The effect of substrate temperature and processing parameters on mechanical properties of nanoscale calcium phosphate coatings are being studied in order to refine the processing technique for Functionally Graded Hydroxyapatite (FGHA) coatings. Coatings were deposited on titanium substrates with a set substrate temperature of 450, 550, 650, or 750 degrees C in an Ion Beam Assisted Deposition (IBAD) system using a sintered hydroxyapatite (HA) target. Mechanical properties of the coatings deposited with a set substrate temperature such as, bonding/adhesion strength to the substrate, nanohardness, and Young's Modulus as well as coating thickness were evaluated and compared with commercial plasma spray HA coatings. It is concluded that depositing FGHA coatings would better be started at 550-650 degrees C to maintain superior properties of the film at the interface. It can also be concluded that the residual stresses caused by different Coefficient of Thermal Expansions (CTEs) between the substrate and coatings are not the only factor controlling the bonding strength and mechanical properties of these samples. Other parameters such as the nature of the interface layers and their bonding to each other as well as the density and grain structure of the coatings must be taken into consideration for an appropriate evaluation of mechanical properties of calcium phosphate coatings deposited on heated substrate.     

Properties and immersion behavior of magnetron-sputtered multi-layered hydroxyapatite/titanium composite coatings

A new biocompatible multi-layered coating was developed by alternately depositing Ti and HA layers on Ti6Al4V substrates using radio frequency magnetron-assisted sputter processing to improve the interface properties between the coating and the substrate. The multi-layered coating consisted of an underlying Ti bond coat, the alternating layer, and an HA top-layer. Between the bond coat and the top layer, an alternating layer was created by means of gradually increasing Ti content with increasing depth from the HA top-layer. The experimental results indicated that the as-sputtered coating had quite uniform thickness and well bonded to the substrate. The multi-layered coating exhibited a better electrochemical behavior than monolithic HA coating. The XRD and low vacuum SEM results consistently indicated that highly crystalline coating was not appreciably dissolvable in simulated body fluid. The adhesion strength higher than 60MPa did not change much even after 14 weeks of immersion. The multi-layered composite coatings had the advantages of high and non-declining adhesion strength and high resistance to SBF attack.     

Characterization of a hydroxyapatite sputtered film subject to hydrothermal treatment using FE-SEM and STEM

Hydroxyapatite (HA) was coated onto a titanium substrate using radio frequency magnetron sputtering. The sputtered film was crystallized using a hydrothermal treatment. The films were observed using X-ray diffractometry, field emission scanning electron microscopy (FE-SEM) and scanning transmission electron microscopy (STEM) equipped with energy dispersive X-ray spectroscopy (EDX).It was observed that the surface of the hydrothermally-treated film was covered with globular particles. The FE-SEM observations indicated that these particles were composed of columnar grains with a grain size of 20-50 nm. In the STEM cross-sectional observation of the HA-Ti interface, HA crystalline phase regions were observed, in part, in the non-crystalline phase layer of the as-sputtered film. After the hydrothermal treatment, the HA layer crystallized; the HA crystallization proceeded to a distance of 30 nm above the titanium surface. From an EDX line scan analysis, the titanium oxide layer was not observed at the HA-Ti interface of the as-sputtered film; however, in the hydrothermally-treated film, the titanium oxide layer, with a 15 nm thickness, was observed between the mixing layer and the titanium substrate. The formation of titanium oxide at the HA-Ti interface would contribute to the adhesion improvement of the sputtered film following the hydrothermal treatment.