Ti6Al4V表面生物功能纯Mg薄膜制备及性能研究

利用多弧离子镀技术在Ti6Al4V表面沉积纯Mg薄膜,研究了工作气压对纯Mg薄膜表面质量及性能的影响,研究了纯Mg薄膜的体外降解等性能、抗菌性及生物安全性能。结果表明:多弧离子镀方法可将纯Mg薄膜制备于钛合金表面,薄膜颗粒均匀致密,未见明显缺陷。体外浸泡实验结果表明:由于Ti6Al4V与Mg发生电偶腐蚀而使Mg薄膜迅速降解,1周时间内薄膜基本降解完毕。抗菌实验结果表明:纯Mg薄膜样品对金黄色葡萄球菌具有强烈的杀灭作用,表现出良好的抗细菌感染功能。细胞毒性实验结果表明:纯Mg薄膜可促进骨髓间充质干细胞(r BMSCs)的增殖。     

盐雾腐蚀条件下Ti合金表面功能薄膜的摩擦磨损性能

目的研究Ti6Al4V合金、铬掺杂类金刚石(Cr-DLC)薄膜、钨掺杂类金刚石(W-DLC)薄膜和氮化钛(TiN)薄膜,在干摩擦和盐雾腐蚀气氛摩擦条件下的摩擦磨损性能。方法在商用Ti6Al4V合金表面通过非平衡磁控溅射制备Cr-DLC薄膜和W-DLC薄膜,通过多弧离子镀技术制备TiN薄膜。利用扫描电镜、显微硬度计、摩擦磨损试验机、白光干涉扫描轮廓仪,对薄膜的形貌、硬度、干摩擦和腐蚀摩擦性能、磨痕形貌进行测试分析。结果干摩擦条件下,Ti6Al4V合金表面沉积Cr-DLC、W-DLC和TiN三种薄膜的摩擦系数均比Ti6Al4V合金低;Ti6Al4V合金及其表面制备的三种薄膜在盐雾腐蚀气氛条件下的摩擦系数都比干摩擦条件下有所增加。与Ti6Al4V合金相比,Cr-DLC、W-DLC和TiN三种薄膜在干摩擦和盐雾腐蚀气氛摩擦条件下均减小了磨损体积。干摩擦条件下,W-DLC薄膜的磨损体积为0.0017 mm~3,耐磨性最好;盐雾腐蚀气氛摩擦条件下,TiN薄膜的磨损体积为0.0028 mm~3,表现出最佳的耐腐蚀磨损性能。通过磨痕形貌可以得出,盐雾腐蚀气氛摩擦条件下,Ti6Al4V合金表面制备的金属掺杂类金刚石薄膜的磨损受到磨粒磨损和腐蚀磨损双重机制的影响。结论三种表面功能薄膜在盐雾腐蚀气氛摩擦条件下都较好地保护了Ti合金,极大地减少了磨损损失。     

粉末冶金法制备Ti6Al4V/20CoCrMo与多孔Ti6Al4V双层生物医用材料的设计与表征

制备Ti6Al4V/20CoCrMo与多孔Ti6Al4V生物医用双层复合材料。采用传统粉末冶金技术,以半固态烧结为固结步骤,制备具有致密Ti6Al4V/20CoCrMo表层和多孔Ti6Al4V底层的双层样品,以更好地模拟天然骨。采用膨胀法研究双层试样的致密化行为,通过扫描电镜(SEM)和显微计算机断层成像(CMT)观察其显微组织,并分别通过压缩试验和动电位试验评价其力学性能和耐腐蚀性能。结果表明,在界面对致密化无负面影响的情况下,可得到无裂纹的双层样品。多孔层的渗透率值在较低的人体骨骼的渗透率范围内。样品的压缩特性由Ti6Al4V多孔层决定。此外,Ti6Al4V/20CoCrMo的耐腐蚀性能优于Ti6Al4V的耐腐蚀性能,提高双层样品的耐腐蚀性。研究粉末冶金法制备具有致密Ti6Al4V/20CoCrMo表层和多孔Ti6Al4V底层的双层结构材料,有助于生产定制化、具有良好磨损性能和体内寿命的植入物。     

厚度和层间界面对Ti6Al4V钛合金抗弹性能的影响

开展了Ti6Al4V钛合金的抗弹性能研究,通过对厚度为10～30 mm的均质Ti6Al4V钛合金靶板和总厚度为30 mm的(15+15)mm双层Ti6Al4V钛合金靶板的终点弹道侵彻实验,研究了厚度和层间界面对Ti6Al4V钛合金抗弹性能的影响规律。结果表明:Ti6Al4V钛合金的抗弹性能随着厚度的增加逐渐提高;在靶板厚度由15 mm增加到20 mm时,其抗弹性能出现了陡增,这与其损伤模式由脆性冲塞破坏转变为塑性扩孔破坏有关;层间界面不利于Ti6Al4V钛合金抗弹性能的提高,厚度为30mm的单层均质Ti6Al4V钛合金靶板的抗弹性能优于总厚度为30mm的(15+15)mm双层Ti6Al4V钛合金靶板,这与双层靶板的层间界面几乎无剪切强度有关。     

Ti6Al4V合金热浸镀铝的空蚀行为研究

采用热浸镀法在Ti6Al4V合金表面制备Ti Al3涂层,并在550℃真空保温5 h。对热浸镀后材料与Ti6Al4V合金进行了空蚀试验对比。通过X射线衍射仪、扫描电镜及显微硬度测量等手段研究了涂层的组织形态和耐空蚀性能。结果表明:热浸镀铝比Ti6Al4V合金空蚀累积质量损失低,具有更好的抗空蚀性能,这与Ti6Al4V合金表面形成的Al3Ti的强化作用有关。热浸镀铝和Ti6Al4V合金空蚀20 h后横截面显微硬度都降低,发生了加工软化现象,使得材料表面逐渐脱落。     

类金刚石薄膜改性钛合金的扭动摩擦磨损特性

以Ti6Al4V合金、类金刚石薄膜(DLC膜)改性Ti6Al4V合金分别与超高分子量聚乙烯(UHMWPE)配副,模拟颈椎间盘的轴向旋转运动,并在改装后的多自由度磨损试验机上进行扭动摩擦试验。结果表明:随着循环周次的增加,两对摩擦副均呈现出摩擦扭转力矩、摩擦耗散能、磨损量相应增大的趋势。与Ti6Al4V合金相比,DLC薄膜改性后的Ti6Al4V合金摩擦副接触界面间摩擦扭转力矩降低了51.6%、摩擦耗散能降低了48%,进入完全滑移状态的时间缩短,具有更好的耐磨性。Ti6Al4V合金的磨损机制表现为严重的磨粒磨损,经DLC薄膜改性后的钛合金的磨损形式以应力集中产生的脆性剥落为主。DLC薄膜增大了对磨副UHMWPE的磨损,UHMWPE的磨损机制是粘着磨损和磨粒磨损综合作用的结果。     

Ti—Al—N薄膜的性能及应用

利用多弧离子沉积技术在W18Cr4V高速钢表面沉积（Ti,Al）薄膜,实验结果表明（Ti,Al）N薄膜的硬度和抗氧化性能明显优于TiN薄膜,（Ti,Al）N膜层刀具的寿命大大高于TiN膜层刀具。     

Ta离子注入Ti6Al4V合金耐磨性研究

用5种Ta离子注入剂量(1.2×1016、3×1016、1.5×1017、3×1017、4.5×1017 ions/cm2)对Ti6Al4V合金进行离子注入表面改性.采用纳米硬度计测量Ta离子注入前后Ti6Al4V合金表面硬度随压入深度的变化,利用多功能摩擦磨损试验机研究Ta离子注入前后Ti6Al4V合金材料的耐磨性,利用X射线衍射技术研究Ta离子注入前后Ti6Al4V合金表面的物相分布.结果表明,除Ta离子注入剂量为3×1017 ions/cm2外,Ta离子注入Ti6Al4V合金硬度有一定的提高;Ta离子注入Ti6Al4V合金摩擦系数降低;除Ta离子注入剂量为3×1017 ions/cm2外,Ta离子注入Ti6Al4V合金的耐磨损性能得到了改善.摩擦系数降低和硬度提高、Ta离子注入的固溶强化、单质Ta新相的弥散强化改善了Ti6Al4V合金的耐磨损性能.     

空心阴极放电复合稀土氧化物对Ti6Al4V合金离子渗氮组织及性能的影响

目的 改善Ti6Al4V合金的耐磨和耐蚀性能,探究辅助渗氮手段的引入对Ti6Al4V合金离子渗氮组织和性能的影响。方法 利用空心阴极放电(Hollow Cathode Discharge,HCD)及稀土氧化物(Y2O3纳米颗粒)辅助在720 ℃对Ti6Al4V合金进行4 h离子渗氮处理。通过光学显微镜、扫描电子显微镜、X射线衍射仪、显微硬度测试仪、往复式摩擦磨损实验仪以及电化学工作站,对比研究常规离子渗氮、HCD辅助离子渗氮以及HCD复合稀土氧化物辅助离子渗氮3种条件下Ti6Al4V合金的渗氮组织和性能。结果 HCD复合稀土氧化物辅助离子渗氮条件下,Ti6Al4V合金表面生成约126 μm厚的渗氮层,分别是常规离子渗氮条件和HCD辅助离子渗氮条件的3.1、2.4倍。化合物层中,TiN含量显著增加,渗氮层表面硬度达到1 067.9HV0.05。渗氮层整体硬度明显提高,且硬度梯度降低。Ti6Al4V合金的摩擦系数从常规离子渗氮时的0.4降至0.2。同时,TiN含量的提高,使Ti6Al4V合金在3.5% NaCl溶液中的自腐蚀电流降低,极化电阻增大,耐蚀性能得到改善。结论 HCD复合Y2O3辅助可显著提高氮势,促进氮向Ti6Al4V合金内快速扩散,提高合金的硬度,改善合金的耐磨性能和耐蚀性能。     

钛合金表面大气压等离子体枪制备类金刚石薄膜

在大气下,采用大气压介质阻挡放电(DBD)等离子体枪在低温下(350℃),以甲烷为单体,氩气为工作气体,在Ti6Al4V钛合金表面制备一层类金刚石薄膜(DLC),以期改善钛合金表面摩擦学性能。利用激光拉曼(Raman)光谱和X射线光电子能谱(XPS)分析了所制备DLC薄膜的结构;利用扫描电子显微镜(SEM)观察DLC薄膜的表面形貌;利用划痕仪测量了DLC薄膜与基体的结合力;利用球-盘摩擦磨损实验仪对DLC薄膜的耐磨性能进行了研究。结果表明:在本实验工艺条件下沉积的类金刚石薄膜厚度约为1.0μm,薄膜均匀且致密,表面粗糙度Ra为13.23nm。类金刚石薄膜与基体结合力的临界载荷达到31.0N。DLC薄膜具有优良的减摩性,Ti6Al4V表面沉积DLC薄膜后摩擦系数为0.15,较Ti6Al4V基体的摩擦系数0.50明显减小,耐磨性能得到提高。     

钛合金表面GO/纳米ZnO复合涂层的制备及性能

为了有效解决生物医用钛合金长期植入人体后,易发生细菌感染和面临有害金属离子释放的问题,采用水热反应和涂覆方法,分别在聚多巴胺(PDA)预处理的Ti6Al4V合金表面制备了氧化石墨烯涂层(GP/T)和氧化石墨烯/纳米氧化锌复合涂层(GZP/T)。系统分析了两种涂层的物相结构、微观形貌、及其在林格氏液中的腐蚀性能和在大肠杆菌环境中的抗菌性能。研究结果表明：聚多巴胺发挥“双面胶”桥接作用,有效增强了涂层与基底间的化学键合；GP/T涂层抗菌率随着GO浓度增大而增大；GZP/T纳米复合涂层相较Ti6Al4V基材具有优异的耐蚀性,该复合涂层中ZnO起主要抗菌作用。     

Triode plasma nitriding and PVD coating: A successful pre-treatment combination to improve the wear resistance of DLC coatings on Ti6Al4V alloy

Diamond-like carbon (DLC) coatings have found great applicability in the automotive industry because of their low friction coefficient and high wear resistance. Nevertheless, their tribological performance can be greatly reduced on soft substrates such as titanium alloys. The hard DLC coating cannot usually follow elastic and plastic deformation of the substrate without failing. In order to overcome this property mismatch between hard coating and soft substrate, triode plasma nitriding was applied as a pre-treatment to improve the mechanical properties of the Ti6Al4V alloy and further enhance the load support for the DLC coating. DLC and multilayered TiN/DLC, CrN/DLC CrAlN/DLC coatings were deposited onto “standard” and plasma nitrided Ti6Al4V substrates. Triode plasma nitriding increased the load-bearing capacity of the coating/substrate system, as higher critical adhesion loads were recorded for DLC coatings on plasma nitrided Ti6Al4V substrates. This treatment also reduced the wear rate of the DLC coating/substrate. Further load support and lower wear rates were achieved by using TiN, CrN and CrAlN as intermediate layers on plasma nitrided Ti6Al4V substrates.     

Preparation and Properties of Biological Functional Magnesium Coating on Ti6Al4V SubstrateEI北大核心CSCD

Currently, metallic biomaterials used in orthopedics are normally bioinert which is hard to integrate with the bone tissue inducing aseptic loosening and easy to get infection, which is the main reason of implantation failure. Mg base metals are considered to be a new generation of revolutionary metallic biomaterials due to its similar density and mechanical properties with natural bone, good biocompatibility, degradability in the body as well as the biological functional ability to promote new bone tissue formation. In addition, the degradation of Mg may increase the local pH which can inhibit the growth of bacteria. In this work, pure Mg coating was deposited on Ti6Al4V substrate by arc ion plating. The effects of different working pressures on the surface quality and properties of Mg coating were investigated. The degradation, antibacterial and biosafety properties were studyied. The results showed that the pure Mg coating can be deposited on the surface of Ti6Al4V substrate and the coating was uniform and smooth. The immersion test in vitro showed that the degradation was very fast because of galvanic corrosion, and the whole process was finished in about one week. The results of antimicrobial experiments showed that the Mg coating can kill staphylococcus aureus and showed good antibacterial function. The results of cytotoxicity test showed that Mg coating promoted rabbit bone marrow mesenchymal stem cells (rBMSCs) growth and proliferation.     

The Tribological Performance of Surface Treated Ti6A14V as Sliding Against Si<Subscript>3</Subscript>N<Subscript>4</Subscript> Ball and 316L Stainless Steel Cylinder

Closed field unbalanced magnetron sputtering was used to deposit diamond-like carbon (Ti-C:H) coatings on Ti6Al4V alloy and gas nitrided Ti6Al4V alloy. Four different specimens were prepared, namely untreated Ti6Al4V alloy (Ti6Al4V), gas nitrided Ti6Al4V alloy (N-Ti6Al4V), Ti-C:H-coated Ti6Al4V alloy (Ti-C:H/Ti6Al4V) and Ti-C:H-coated gas nitrided Ti6Al4V alloy (Ti-C:H/N-Ti6Al4V). The tribological properties of the four specimens were evaluated using a reciprocating wear tester sliding against a Si₃N₄ ball (point contact mode) and 316L stainless steel cylinder (line contact mode). The wear tests were performed in a 0.89 wt.% NaCl solution. The results showed that the nitriding treatment increased the surface roughness and hardness of the Ti6Al4V alloy and improved the wear resistance as a result. In addition, the Ti-C:H coating also improved the tribological performance of Ti6Al4V. For example, compared to the untreated Ti6Al4V sample, the Ti-C:H coating reduced the wear depth and friction coefficient by 340 times and 10 times, respectively, in the point contact wear mode, and 151 times and 9 times, respectively, in the line contact wear mode. It is thus inferred that diamond-like carbon coatings are of significant benefit in extending the service life of artificial biomedical implants.     

Design and characterization of selective laser-melted Ti6Al4V–5Cu alloy for dental implants

Ti6Al4V–5Cu alloys have potential biomedical applications due to their adequate antibacterial properties. However, the wear and corrosion properties of these alloys are also crucial for dental implants. In the present study, Ti6Al4V–5Cu alloys were fabricated by selective laser melting (SLM). The microstructure and composition of Ti6Al4V–5Cu alloys by SLM were evaluated. The wear properties of the alloys in the simulated saliva environment and the atmospheric environment, as well as the electrochemical properties in the simulated saliva environment, were systematically investigated. The results showed that the crystal structure of Ti6Al4V–5Cu alloys was mainly composed of α-Ti and Ti₂Cu. In the SLM process, no preferred texture was observed due to the complex direction of the heat flux. The formation of Ti₂Cu can improve the strength of the material and make the titanium copper alloy have higher microhardness. Ti6Al4V–5Cu alloy showed a satisfactory wear resistance in both wear media. The addition of Cu reduced the second-phase content of the alloy. Meanwhile, the number of microcells was reduced, which was a positive factor to improve the corrosion resistance of the alloys.     

Effects of Duplex Nitriding and TiN Coating Treatment on Wear Resistance,Corrosion Resistance and Biocompatibility of Ti6Al4V Alloy

Ti6Al4V alloy substrates were nitrided at 900 °C. TiN coatings were then deposited on the nitrided substrates using a closed-field unbalanced magnetron sputtering system. The microstructure, hardness and adhesion properties of the TiN-N-Ti6Al4V substrates were evaluated and compared with those of an untreated Ti6Al4V sample, a nitrided Ti6Al4V sample and a TiN-coated Ti6Al4V sample, respectively. The tribological properties of the various samples were investigated by means of reciprocating sliding wear tests performed in 0.9 wt.% NaCl solution against 316L, Si₃N₄ and Ti6Al4V balls, respectively. In addition, the corrosion resistance was evaluated using potentiodynamic polarization tests. Finally, the biocompatibility of the samples was investigated by observing the attachment and growth of purified mouse leukemic monocyte/macrophage cells (Raw 264.7) on the sample surface after culturing periods of 24, 72 and 120 h, respectively. Overall, the results showed that the duplex nitriding/TiN coating treatment significantly improved the tribological, anti-corrosion and biocompatibility properties of the original Ti6Al4V alloy.     

Cu/Mo双涂层改性SiCf/Ti6Al4V复合材料的界面与性能

采用箔-纤维-箔(FFF)法分别制备无涂层、C涂层和Cu/Mo双涂层改性的SiCf/Ti6Al4V复合材料,对制备态复合材料的力学性能和界面微观组织进行对比分析,进一步研究不同真空热暴露处理对Cu/Mo双涂层改性复合材料的界面微区的影响规律。结果表明,制备态下Cu/Mo涂层比C涂层较好地改善了复合材料的界面组织和性能,且对基体和纤维中元素扩散均具有一定的阻挡作用;求得900℃下SiCf/Cu/Mo/Ti6Al4V界面反应的生长动力学公式为H=1.380t1/2+5.397。     

Preparation of titanium oxide and hydroxyapatite on Ti–6Al–4V alloy surface and electrochemical behaviour in bio-simulated fluid solution

In order to improve the bonding strength between hydroxyapatite (HA) coating and Ti–6Al–4V substrate, a uniform titanium oxide film was obtained by controlled anodic oxidation. After that an alkaline treatment with NaOH solution was used to make them more bioactive. Finally hydroxyapatite coating has been prepared on Ti–6Al–4V substrate through electrochemical deposition. Comparative electrochemical behaviour of untreated and surface modified Ti–6Al–4V alloy, in bio-simulated fluid solution was investigated by electrochemical techniques. SEM was used to observe the morphology of modified surfaces and the thicknesses of the oxide films prepared were evaluated on the cross-sections of the samples using SEM–FIB.     

Fabrication and Characterization of Nanopillar-Like HA Coating on Porous Ti6Al4V Scaffold by a Combination of Alkali–Acid-Heat and Hydrothermal Treatments

Porous titanium scaffold with suitable porous architecture exhibits enormous potentials for bone defect repairs. However,insufficient osteointegration and osteoinduction still remain to open as one of the major problems to achieve satisfactory therapeutic effect. To solve this problem, many studies have been carried out to improve the bioactivity of porous titanium scaff old by surface modifications. In this study, porous Ti6Al4V scaff olds were fabricated using additive manufacturing technique. Porous architectures were built up based on a diamond pore structure unit. Alkali–acid-heat(AH) treatment was applied to create a TiO_2 layer on the porous Ti6Al4V scaff old(AH-porous Ti6Al4V). Subsequently, a hydrothermal treatment was employed to enable the formation of HA coating with nanopillar-like morphology on the alkali–acid-heat-treated surface(HT/AH-porous Ti6Al4V). The effects of surface modifications on apatite-forming ability, protein adsorption,cell attachment, cell proliferation and osteogenic gene expression were studied using apatite-forming ability test, protein adsorption assay and in vitro cell culture assay. It was found that the HT/AH-porous Ti6Al4V exhibited the highest apatite formation ability and best affinity to fibronectin and vitronectin. In vitro studies indicated that the mesenchymal stem cells(MSCs) cultured on the HT/AH-porous Ti6Al4V presented improved adhesion and differentiation compared with the porous Ti6Al4V and AH-porous Ti6Al4V.     

Wear, erosion and corrosion resistance of CrTiAlN coating deposited by magnetron sputtering

A nanolayered CrTiAlN coating, which was deposited on Ti6Al4V substrate using unbalanced magnetron sputtering technique, was tested to evaluate its performances against wear, erosion and corrosion. The coating, with a higher hardness compared to CrN, demonstrates significantly higher dry sliding wear resistance than CrN and TiN coatings. Different from the brittle TiN coating, the CrTiAlN coating has a maximum erosion rate at an impingement angle of 45° and shows better erosion resistance than TiN coating at 90°. The CrTiAlN coated Ti6Al4V, when tested in 3.5% NaCl aqueous solution, shows a markedly more noble corrosion potential in comparison with the uncoated Ti6Al4V substrate. Furthermore, it demonstrates a wide passive region with a low current density. All these properties make the CrTiAlN coating a good candidate for a variety of industrial applications.