Ti6Al4V-TiN和Ti6Al4V-TiN-TiC生物梯度材料的血液相容性评价

采用体外试验法对Ti6Al4V-TiN和Ti6Al4V-TiC生物梯度材料及其它几种常用人工心脏瓣膜材料的体外动态凝血时间、溶血率、血小板消耗率进行了测定,并对这几种材料的血液相容性进行了对比,得到以下结论.(1)以动态凝血时间为指标,有LTI碳＞DLC膜＞TiN＞TiC＞Ti6Al4V.(2)以血小板消耗率为指标,有LTI碳＞DLC膜＞TiN＞Ti6Al4V＞TiC.(3)以溶血率为指标,有LTI碳＞DLC膜＞TiN＞TiC＞Ti6Al4V.     

利用掺杂及梯度复合技术对生物材料进行TiO2(Ta5+)/TiN薄膜表面改性的研究

采用磁控溅射技术同热氧化相结合的方法合成TiO2(Ta5 )/TiN复合薄膜,并对薄膜的硬度、摩擦磨损等力学特性以及血小板粘附等血液相容性进行了研究.研究结果表明,掺杂使血液相容性提高,梯度复合使力学特性改善,因而薄膜具有良好的力学耐久性和血液相容性.此外,薄膜与血液的界面张力也被测试.结果表明,低的薄膜/血液界面张力改善了TiO2(TA5 )/TiN复合薄膜的血液相容性.     

P掺杂类金刚石薄膜的制备及生物学行为研究

应用等离子体浸没离子注入与沉积方法合成了磷掺杂的类金刚石(diamond like carbon,DLC)薄膜.结构分析表明磷以微米级岛状结构分散于DLC薄膜表层,P的掺杂增加了DLC薄膜的无序性,俄歇能谱表明岛型区域是由P、C、O三种元素形成的化合物.掺杂表面表现出强烈的亲水性(水接触角为16.9°),体外血小板粘附实验结果显示,P掺杂DLC薄膜表面粘附的血小板少且变形小,表现出的血液相容性优于热解碳和未改性DLC.     

磷掺杂类金刚石薄膜的制备与性能研究

应用等离子体浸没离子注入与沉积方法合成了磷掺杂的类金刚石(P doped diamond like carbon,P-doped DLC)薄膜.结构分析表明磷以微米级岛状结构分散于DLC薄膜表层,P的掺杂增加了DIE薄膜的无序性,俄歇能谱证明岛型区域是由P、C、O三种元素形成的化合物,衰减全反射傅里叶红外光谱(ATR-FTIR)的分析结果显示存在P-O-P和P-O-C的非对称伸缩振动.掺杂表面表现出强烈的亲水性(水接触角为16.9°),体外血小板粘附实验结果显示,P掺杂DLC薄膜表面粘附的血小板少且变形小,表现出的血液相容性优于热解碳和未改性DLC.P-doped DLC薄膜与水的界面张力为2.7 Nj/cm2,具有较理想的接近于血细胞的界面张力,因此与血液保持了较高的相容性.     

NiTi 合金表面激光原位反应合成TiN增强金属基复合材料涂层

采用连续高功率固体Nd-YA G激光辐照, 使预置于NiTi 合金表面的Ti 粉在N₂ 环境中形成TiN 增强Ti 基复合材料涂层。选择适当的激光辐照工艺参数, 获得致密的TiN 增强金属基复合材料激光改性层。SEM 观察及EDAX 成分分析结果表明, TiN/ Ti 金属基复合材料表面改性层与基体NiTi 合金存在良好的冶金结合, 界面处成分均匀过渡, 表面Ni 含量极低。显微硬度测试及磨损实验表明, TiN/ Ti 金属基复合材料改性层显著提高了NiTi 合金的表面硬度和耐磨性, 激光表面改性层可有效地改善NiTi 合金作为生物医学材料使用的表面成分和性能。      

NiTi合金生物医用材料表面镀类金刚石薄膜的性能研究

用脉冲电弧离子镀技术在NiTi合金生物材料表面沉积了类金刚石(DLC)薄膜.研究分析结果表明制备的DLC薄膜是四面体非晶碳薄膜;随着DLC薄膜厚度的增加,薄膜的表面粗糙度增加,薄膜中sp3的含量减少;随着sp3含量的增加,薄膜的纳米硬度升高;划痕实验表明临界载荷大于0.9 N.研究得出与NiTi合金相比,DLC薄膜能够有效地降低摩擦系数和磨损.DLC薄膜的摩擦系数主要与薄膜的硬度及薄膜中sp3的含量有关,DLC薄膜的磨损主要是轻微的磨粒磨损及疲劳磨损.     

溶胶-凝胶法制备TiO2与SiO2-TiO2薄膜对医用NiTi合金的表面改性

采用溶胶－凝胶法制备TiO2与SiO2-TiO2薄膜，对医用NiTi合金进行表面改性处理，利用X射线衍射（XRD）、原子力显微镜（AFM）、划痕试验和电化学腐蚀试验等手段系统研究了薄膜结构、形态及性能。通过动态凝血时间和血小板粘附的测量研究和评价了薄膜的体外血液相容性。结果表明，在一定范围内，较高热处理温度有利于薄膜与基体间的结合强度和耐腐蚀性的提高；NiTi合金表面镀TiO2与SiO2-TiO2薄膜后，其血液相容性明显提高。     

生物可降解Mg-2Zn-0.2Mn合金的体外生物相容性

采用真空铸造技术制备了Mg-2Zn-0.2Mn三元镁合金,并对该合金体外生物生物相容性能进行了研究。采用血小板粘附、溶血率评价镁合金的血液相容性,采用细胞增殖实验(CCK-8)、细胞凋亡实验(AO/PI)评价镁合金的细胞相容性。结果表明:血小板粘附实验表明,与常用的AZ31B镁合金和316L不锈钢样品相比较,Mg-2Zn0.2Mn镁合金表面粘附的血小板数量少,且激活和团聚较轻微;溶血实验的结果表明Mg-2Zn0.2Mn的溶血率为4.7%,远小于AZ31B的80.9%溶血率。血小板黏附和溶血实验说明Mg-2Zn0.2Mn镁合金具有优异的血液相容性。细胞增殖和凋亡实验结果也表明,较AZ31B样品,Mg-2Zn0.2Mn样品表面显示了更好的内皮细胞粘附和增殖能力,说明Mg-2Zn0.2Mn镁合金具有很好的血液相容性和内皮细胞相容性,有望作为今后可降解血管支架的候选材料。     

离子束合成TiO2薄膜对医用NiTi合金表面的改性

采用离子束增强沉积法制备TiO2薄膜,对医用NiTi合金进行表面改性处理。系统研究了薄膜的表面组成、结构、形貌及耐蚀性、亲水性等与血液相容性相关的表面性质。NiTi合金表面沉积TiO2薄膜后,抗模拟体液的腐蚀性提高,凝血时间延长。为进一步提高TiO2薄膜的抗凝血性,对TiO2薄膜的进一步表面改性－表面结合肝素分子进行了初步尝试,结果表明,薄膜表面组成发生变化,表面亲水性进一步提高。     

NiTi合金低压等离子渗氮研究

采用低压等离子渗氮工艺对NiTi合金进行了渗氮处理.氮化处理后NiTi合金表面硬度升高.XRD测试结果表明在合金表面形成了一层TiN涂层,在TiN涂层下为Ni3Ti相.电化学腐蚀测试表明经氮化处理后合金的耐腐蚀能力大为提高.     

基于RFPECVD方法不锈钢上沉积类金刚石薄膜的机械与摩擦特性

讨论用射频等离子体增强化学气相沉积(RFPECVD)工艺,在室温下实现在1Cr18Ni9Ti不锈钢基底上镀类金刚石(DLC)膜.为提高DLC膜的结合力,首先在不锈钢基底上沉积Ti/TiN/TiC功能梯度膜.借助所设计的界面过渡层,成功地在不锈钢基底上沉积了一定厚度的DLC膜.通过优化沉积参数,所沉积的DLC膜在与100Cr6钢球对磨时摩擦系数低于0.020.在摩擦过程中DLC膜的磨损机制借助SEM、Raman分析进行了研究.     

结构调制超硬Ti/TiN纳米多层膜的制备及其尺寸效应

使用多弧离子镀技术在高速钢基体上制备了调制周期为5~40 nm的Ti/TiN纳米多层膜,用扫描电子显微镜(SEM)、X射线能谱仪(EDS)、X射线衍射仪(XRD)、纳米压痕仪和划痕仪等手段表征薄膜的微观结构和性能,研究了调制周期对Ti/TiN纳米多层膜性能的影响,并讨论了在小调制周期条件下Ti/TiN纳米多层膜的超硬效应和多弧离子镀技术对纳米多层膜硬度的强化作用。结果表明,与单层TiN相比,本文制备的Ti/TiN纳米多层膜分层情况良好,薄膜均匀致密,没有明显的柱状晶结构,TiN以面心立方结构沿(111)方向择优生长。随着调制周期的减小薄膜的硬度呈现先增大后减小的趋势,并在调制周期为7.5 nm时具有最大的硬度42.9 GPa和H/E值。这表明,Ti/TiN在具有最大硬度的同时仍然具有良好的耐磨性和韧性。Ti/TiN纳米多层膜的附着力均比单层TiN薄膜的附着力高,调制周期为7.5 nm时多层膜的附着力为(58±0.9) N。     

Influence of Ti/TiN bilayered and multilayered films on the axial fatigue performance of Ti46Al8Nb alloy

The effects of Ti/TiN bi- and multilayered films on the fatigue performance of the Ti46Al8Nb alloy were investigated. Ti/TiN films with a total thickness of 1 μm were deposited on the Ti46Al8Nb alloy substrate by the hollow cathode deposition method. The samples were examined with various analytical techniques including nanoindentation, scratch test, stripping layer substrate curvature test and scanning electron microscopy. The results show that multilayered Ti/TiN films can enhance the fatigue strength of the Ti46Al8Nb alloy, whereas bilayered films have no obvious effect. Compared with the bilayer, the multilayer exhibits higher hardness, higher residual compressive stress and higher adhesion strength to the substrate. It is also demonstrated that the multilayer is responsible for retarding fatigue crack growth. All the superior properties make the hard Ti/TiN multilayer to be an effective protection coating for the enhanced fatigue strength of the brittle substrate.     

Characterization of the Diamond—like Carbon based Functionally Gradient Film

Diamond-like carbon coatings have been used as solid lubricating coatings in vacuum technology for their good physical and chemical properties. In this paper, the hybrid technique of unbalanced magnetron sputtering and plasma immersion ion implantation (Pill) was adopted to fabricate diamond-like carbon-based functionally gradient film, N/TiN/Ti(N,C)/DLC, on the 304 stainless steel substrate. The film was characterized by using Raman spectroscopy and glancing X-ray diffraction (GXRD), and the topography and surface roughness of the film was observed using AFM. The mechanical properties of the film were evaluated by nano-indentation. The results showed that the surface roughness of the film was approximately 0.732 nm. The hardness and elastic modulus, fracture toughness and interfacial fracture toughness of N/TiN/Ti(N,C)/DLC functionally gradient film were about 19.84 GPa, 190.03 GPa, 3.75 MRa.m1/2 and 5.68 MPa-m1/2, respectively. Compared with that of DLC monolayer and C/TiC/DLC multilayer, this DLC grad     

(Ti,Al,Zr)N多元氮梯度硬质反应膜的组织结构和性能

采用多弧离子镀技术和Ti-Al合金靶及Zr单质靶的组合,在高速钢基体上制备了(Ti,Al,Zr)N多元N梯度硬质反应膜.分别用扫描电镜、X射线衍射仪观察测定(Ti,Al,Zr)N梯度膜膜层的表面、断面形貌、成分以及相结构,研究了(Ti,Al,Zr)N多元氮梯度硬质反应膜的组织结构和性能.结果表明,与TiN、(Ti,Al...     

等离子体基离子注入制备TiN膜的成分结构

采用Ti、N等离子体基离子注入和先在基体表面沉积纯钛层然后离子注氮混合两种方法在铝合金基体上制备了TiN膜.利用XPS分析了两种方法制备TiN薄膜的成分深度分布和元素化学价态,并用力学性能显微探针测试对比了TiN膜的纳米硬度.研究表明:两种方法制备的薄膜均由TiN组成,Ti、N等离子体基离子注入薄膜中Ti/N≈1.1,而离子注入混合薄膜中Ti/N≈1.3,Ti、N等离子体基离子注入薄膜表面区域为TiN和TiO2的混合组织,TiN含量多于TiO2,离子注入混合薄膜表面主要是TiO2;Ti、N等离子体基离子注入所制备的薄膜的纳米硬度峰值为12.26 GPa,高于离子注入混合的7.98 GPa.     

Deposition of boron doped DLC films on TiNb and characterization of their mechanical properties and blood compatibility

Abstract

Diamond-like carbon (DLC) material is used in blood contacting devices as the surface coating material because of the antithrombogenicity behavior which helps to inhibit platelet adhesion and activation. In this study, DLC films were doped with boron during pulsed plasma chemical vapor deposition (CVD) to improve the blood compatibility. The ratio of boron to carbon (B/C) was varied from 0 to 0.4 in the film by adjusting the flow rate of trimethylboron and acetylene. Tribological tests indicated that boron doping with a low B/C ratio of 0.03 is beneficial for reducing friction (μ = 0.1), lowering hardness and slightly increasing wear rate compared to undoped DLC films. The B/C ratio in the film of 0.03 and 0.4 exhibited highly hydrophilic surface owing to their high wettability and high surface energy. An in vitro platelet adhesion experiment was conducted to compare the blood compatibility of TiNb substrates before and after coating with undoped and boron doped DLC. Films with highly hydrophilic surface enhanced the blood compatibility of TiNb, and the best results were obtained for DLC with the B/C ratio of 0.03. Boron doped DLC films are promising surface coatings for blood contacting devices.     

XPS and biocompatibility studies of titania film on anodized NiTi shape memory alloy

A dense titania film is fabricated in situ on NiTi shape memory alloy (SMA) by anodic oxidation in a Na₂SO₄ electrolyte. The microstructure of the titania film and its influence on the biocompatibility of NiTi SMA are investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma mass spectrometry (ICPMS), hemolysis analysis, and platelet adhesion test. The results indicate that the titania film has a Ni-free zone near the surface and can effectively block the release of harmful Ni ions from the NiTi substrate in simulated body fluids. Moreover, the wettability, hemolysis resistance, and thromboresistance of the NiTi sample are improved by this anodic oxidation method.     

Adhesion studies of diamond-like carbon films deposited on Ti6Al4V substrate with a silicon interlayer

Diamond-like carbon (DLC) films have proven quite advantageous in many tribological applications due to their low friction coefficient, their extreme hardness, and more recently their high adherence on different substrate materials. However, for many applications, DLC films as thick as 2 μm are required, which cause high residual stress. In order to overcome this problem, this study observed the behavior of different thicknesses of silicon interlayer between DLC films and Ti6Al4V substrates. The study also analyzed the relation of growth parameters to the mechanical properties of DLC films. Silicon and DLC films were grown by using a rf-PECVD at 13.56 MHz with silane and methane atmospheres, respectively. The contribution of an interlayer thickness to the adhesion between the DLC films and Ti6Al4V substrate was evaluated by using a micro-scratch technique. The hardness and friction coefficient were evaluated by using microindentation and lateral force microscopy (LFM), respectively. Raman scattering spectroscopy was used to characterize the film quality. A correlation was found between the intrinsic stress and adhesion of DLC film and the parameters of the silicon interlayer growth. The addition of a silicon interlayer successfully reduced intrinsic stress of the films, even as measured by using a perfilometry technique.     

多弧离子镀(Cr,Ti,Al,Zr)N多组元超硬梯度膜的结构及性能

(Cr,Ti,Al,Zr)N梯度膜性能优异。采用多弧离子镀技术,使用Ti-Al-Zr合金靶和Cr单质靶在高速钢表面制备(Cr,Ti,Al,Zr)N多元超硬梯度膜,利用扫描电镜、能谱、X射线衍射仪、硬度计、划痕仪对膜层形貌、成分、结构、硬度、附着力进行分析,并通过热震性能试验考察了膜层的抗热震性能。结果表明:制备的膜层为面心立方结构,择优生长取向为(220)面;与TiN,(Ti,Al)N,(Ti,Cr)N,(Ti,Al,Zr)N等硬质膜相比,制备的(Cr,Ti,Al,Zr)N多元梯度膜具有更高的硬度和膜/基附着力,硬度可达4400HV,膜/基附着力大于200N,实现了从硬质膜到超硬膜的转变;膜层中N含量梯度可有效减少应力集中,Cr,Al含量的增加有利于提高膜层抗热震性能;负偏压对膜层硬度影响较大,对膜层成分、结构、抗热震性能影响较小,对膜/基附着力基本无影响。