钛合金表面湿法制备磷灰石涂层

钛合金经不同碱热处理后,浸泡在快速钙化溶液(FCS)中,使基体表面化学沉积出磷灰石涂层.文中讨论了碱热处理对基体表面诱导沉积磷灰石的影响,以及在沉积过程中磷灰石涂层在不同生长时期的形态.     

Thermal Treatment Optimization of Electrodeposited Hydroxyapatite Coatings on Ti6Al4V Substrate

Thermal behavior of electrodeposited hydroxyapatite (HAP) coating on a titanium alloy (Ti6Al4V) is investigated in order to optimize the heat treatment conditions for this prosthetic material. The synthesized coatings are annealed in air atmosphere at 400, 600, 800, and 1000 °C, and then characterized by X‐ray diffraction (XRD) and selected area electron diffraction (SAED) for structure and phases analysis. Scanning and transmission electron microscopy associated to energy dispersive X‐ray microanalysis (SEM‐EDXS and STEM) are used for morphology and composition analysis. The results show that when the electrodeposited coating is annealed at temperatures greater than 600 °C, a well‐crystallized HAP is obtained with a notable change of its morphology. However, at these temperatures the surface of Ti6Al4V alloy (uncoated zones of the implant) is deteriorated by the formation of a thick surface oxide layer. Therefore, we limit the heat treatment temperature for the electrodeposited coatings on a Ti6Al4V alloy at 550 °C. At this optimized temperature it is demonstrated that the link between the coating and the substrate is improved and the crystallinity of the coating is controlled which make it well bioactive.     

Cu调控的TiN-Cu纳米复合膜包覆钛合金的抗菌性研究

利用磁控共溅射技术在钛合金(Ti6Al4V)表面包覆氮化钛-铜纳米(TiN-Cu)复合膜,并通过控制Cu靶溅射功率实现对TiN-Cu薄膜中Cu含量的调节,进而实现对材料耐蚀性和抗菌性的协同调控。采用扫描电子显微镜、原子力显微镜、X射线衍射仪、能谱仪分析了包覆TiN-Cu纳米复合膜的钛合金的表面形貌、相结构、元素成分及价态,并在模拟体液条件下测试了该材料的耐腐蚀性能,通过体外抗菌实验评价了Cu含量对材料抗菌性的影响。结果表明:通过在Ti6Al4V表面包覆TiN-Cu纳米复合薄膜显著增强了材料的抗菌性;并抑制了有毒性的V⁴⁺、Al³⁺离子在体液中的释放。Cu靶溅射功率升高在提高TiN-Cu薄膜中Cu含量和薄膜沉积速率的同时,也导致了薄膜中大量柱状晶体结构的生成,加速了薄膜的腐蚀,但提高了抗菌性。综上,合理调控Cu的含量是协同提升TiN-Cu薄膜的耐腐蚀性及抗菌性的关键。     

Ti6Al4V磁控溅射沉积Ti-Ag-(N)薄膜及其抗菌性的研究

利用磁控溅射法在医用钛合金Ti6Al4V表面制备Ti-Ag、Ti-Ag-N薄膜。采用扫描电子显微镜、X射线衍射、X射线能量色散谱、X射线光电子能谱分析薄膜的表面形貌、微观结构、化学成分和化学价态。采用平板计数法测试薄膜对大肠杆菌的抗菌性。研究结果表明:薄膜主要由Ti、Ag、(N)组成,且Ag是以Ag~0形式存在;与基材相比,两种薄膜对大肠杆菌(E.coli)均有抗菌性,且Ti-Ag-N薄膜表现出更优越的抗菌性能。     

电沉积磷酸钙生物陶瓷涂层的研究进展

综述了用电沉积法在金属生物材料表面沉积磷酸钙盐生物活性陶瓷工艺及工艺进展,分析了电沉积的主要控制因素,总结了该技术的特点并展望了其应用前景.     

Ti6Al4V合金表面耐磨涂层的研究进展

评述了Ti6Al4V合金表面耐磨涂层的最新研究进展，特别对新的微弧氧化陶瓷涂层予以关注，并由此提出了深入研究的方向。     

Tribological Properties of Mo-N Hard Coatings on Ti6Al4V by Double Glow Discharge Technique

Mo-N hard coatings on Ti6Al4V were formed using double glow discharge technique. The fundamental coating properties, such as the phase, hardness and elastic modulus were investigated. The tribological performances of the coatings in dry wear condition were studied by means of ball-on-disc wear machine. The experimental results showed that the thickness of the Mo-N hard coating was about 10 µm. The coating was single fcc γ-Mo2N phase with (200) preferred orientation. The hardness and the elastic modulus of the coating was 13.80 GPa and 261.65 GPa respectively. The surface treatment enhanced the hardness and elastic modulus of the surface of Ti6Al4V base greatly. With GCr15 slider ball, the friction coefficient of the Mo-N hard coating was in the range of 0.56~0.65 at the steady state. Though the coating did not show friction reducing effect, it improved the wear resistance of Ti6Al4V greatly.     

AZ31和Ti6Al4V表面Nb2O5涂层的微观结构与性能研究

采用射频溅射技术在AZ31镁合金和Ti6Al4V钛合金表面分别沉积Nb2O5陶瓷涂层,对比研究其微观结构、残余应力、附着力和耐腐蚀性能。研究结果表明：两种涂层试样表面组织致密,颗粒大小均匀,无明显的裂纹和孔洞等缺陷。当Nb2O5涂层的厚度为1.98 μm时,Ti6Al4V涂层试样的残余应力（27.1 MPa）比AZ31涂层试样的小65.1%,附着力（9.24 N）比AZ31涂层试样的大13.2倍。Nb2O5陶瓷涂层能明显提高Ti6Al4V和AZ31的耐腐蚀性能,但在腐蚀电流密度的降低幅度、极化电阻的增大程度和保护效率方面,镁合金涂层试样优于钛合金涂层试样。     

Ti、Ti6Al4V和Ti6Al7Nb对成骨细胞生物活性影响的研究

研究Ti、Ti6Al4V和Ti6Al7Nb 3种钛金属表面经喷砂酸蚀处理后的表面形貌、亲水性及对成骨细胞生物活性的影响。在Ti、Ti6Al4V和Ti6Al7Nb 3种钛金属表面进行Al2O3喷砂和盐酸、硫酸混合物酸蚀的表面改性处理(SLA),通过扫描电子显微镜(scanning electron microscope,SEM)观察样品的表面形貌,通过接触角测量仪在显微镜下测量接触角的大小;将SD大鼠成骨细胞以1×104cells/m L密度接种于Ti、Ti6Al4V和Ti6Al7Nb表面后通过MTT活性实验观察成骨细胞在样品表面的增殖,通过SEM观察细胞在样品表面生长的形态,通过碱性磷酸酶(AKP)活性实验,检测成骨细胞的分化能力。Ti、Ti6Al4V和Ti6Al7Nb在经过喷砂酸蚀处理后,表面均呈现出微米级多孔形貌,3种样品均为亲水性表面;细胞在SLA处理后的Ti、Ti6Al4V和Ti6Al7Nb表面增殖良好,细胞伸展显著;其中在Ti6Al7Nb表面细胞的增殖、黏附、分化能力最强。大颗粒喷砂酸蚀技术的表面处理方法能够促进Ti、Ti6Al4V和Ti6Al7Nb的生物活性;经SLA处理的Ti6Al7Nb比Ti和Ti6Al4V表现出更好的生物学活性,成骨细胞在其表面呈现出更好的增殖、黏附及分化能力。     

Ti6Al4V表面HAF/YSZ梯度复合涂层的制备和性能

采用射频磁控溅射技术在Ti6Al4V基体上制备含氟羟基磷灰石(HAF)梯度复合涂层,对涂层的氟含量、物相组成及形貌进行了表征,并分析了梯度复合涂层在模拟人体条件下的生物活性和稳定性。结果表明:复合涂层中的氟呈梯度分布,n(Ca)/n(P)随着涂层中氟含量的增加逐渐减小。HAF/YSZ(Y_2O_3稳定的ZrO_2,简称YSZ)复合涂层在SBF环境下生成的新物质为碳酸类骨磷灰石,氟促进磷灰石相的发育,氟含量呈梯度分布能有效提高涂层的抗体液溶解能力和与基体间的结合性能;HAF/YSZ梯度复合涂层比无氟羟基磷灰石及氟含量单一的涂层具有更好的生物活性和稳定性。     

电参数对Ti6Al4V合金微弧氧化陶瓷膜结构特性的影响

采用交流微弧氧化法于Na₂SiO₃-KOH-(NaPO₃)₆。溶液中在Ti6A14V表面形成了氧化物陶瓷膜.研究了微弧氧化电压与频率对陶瓷膜的生长速率、组织形貌和相组成的影响.结果表明:随电压的升高或频率的减小,膜层的生长速率增加,膜层的表面质量变得粗糙.相对致密均匀的膜层主要由TiO₂(锐钛矿相及金红石相)相组成,电压与频率电参数影响膜层的相组成,随电压的升高和频率的减小,膜层中锐钛矿相TiO₂的相对含量减小,金红石相TiO₂的相对含量增加,并成为主晶相.     

Tribological behaviour of Ti6Al4V modified by surface treatments

At present, there are no good materials that can substitute ultra-high molecular weight polyethylene (UHMWPE), therefore the only way forward is to find a material for femoral heads with high wettability and hardness able to minimize the wear phenomena between metal and UHMWPE. In this work, the effects of surface treatments to improve the tribological behaviour of titanium alloy (Ti6Al4V) were studied. Ion implantation, CVD and PVD were the surface treatments investigated. Ti6Al4V modified and not modified samples were tested against -ray sterilized UHMWPE pins using a pin-on-flat wear test machine. The results have been compared with the wear behaviour of stainless steel (AISI 316L). Tests were carried out in accordance with ASTM F 732-82 practice, a specific wear test for materials used in total joint prostheses. Metal samples were characterized by SEM micrographs, roughness and hardness measurements, wettability and friction coefficient. UHMWPE wear rates were assessed by weighing the pins at intervals of 250 000 cycles and were expressed by linear regression analysis applied to the weight losses. Ion implantation of the titanium alloy results in lower wear of UHMWPE pins, in particular, chromium implantation is the most efficient among all surface treatments. A tentative explanation of the results is given.This paper was accepted for publication after the 1995 Conference of the European Society of Biomaterials, Oporto, Portugal, 10–13 September.     

A comparative study of the impurity segregation from commercially pure Ti, Ti6Al4V and Ti3Al8V6Cr4Zr4Mo

The surface composition of commercially pure Ti, Ti6Al4V and Ti3Al8V6Cr4Zr4Mo during annealing at different constant temperatures was experimentally investigated. Auger electron spectroscopy was used to monitor the APPHs of the specified elements present on the surfaces. The surfaces of Ti and its alloys were contaminated by oxygen and carbon, and the contamination is attributed to the continual uptake of the background gases, even in the UHV chamber. It was found that mainly C and S segregated at 400 °C, and Cl at higher temperatures (500–630 °C) for commercially pure Ti. However, S was the main segregating species for all three samples. The segregation of Al was measured for the Ti6Al4V and Ti3Al8V6Cr4Zr4Mo samples at higher temperatures. The linear least-square fit method was employed to determine the contribution of pure Ti and TiC from the measured APPH's. The AES fitting confirmed the formation of TiC on the surface at temperatures 400–500 °C.     

Improved thrombogenicity on oxygen etched Ti6Al4V surfaces

Thrombus formation on blood contacting biomaterials continues to be a key factor in initiating a critical mode of failure in implantable devices, requiring immediate attention. In the interest of evaluating a solution for one of the most widely used biomaterials, titanium and its alloys, this study focuses on the use of a novel surface oxidation treatment to improve the blood compatibility. This study examines the possibility of using oblique angle ion etching to produce a high quality oxide layer that enhances blood compatibility on medical grade titanium alloy Ti6Al4V. An X-ray photoelectron spectroscopy (XPS) analysis of these oxygen-rich surfaces confirmed the presence of TiO₂ peaks and also indicated increased surface oxidation as well as a reduction in surface defects. After 2 h of contact with whole human plasma, the oxygen etched substrates demonstrated a reduction in both platelet adhesion and activation as compared to bare titanium substrates. The whole blood clotting behavior was evaluated for up to 45 min, showing a significant decrease in clot formation on oxygen etched substrates. Finally, a bicinchoninic acid (BCA) total protein assay and XPS were used to evaluate the degree of key blood serum protein (fibrinogen, albumin, immunoglobulin G) adsorption on the substrates. The results showed similar protein levels for both the oxygen etched and control substrates. These results indicate that oblique angle oxygen etching may be a promising method to increase the thrombogenicity of Ti6Al4V.     

凝胶注模成形Ti6Al4V钛合金的组织和性能研究

目的 为了实现低成本、低能耗、高效率制备大尺寸复杂形状钛合金的问题,以凝胶注模技术为成形手段,制备近净成形Ti6Al4V合金,并研究其组织及性能.方法 通过溶液包覆法,在Ti6Al4V钛合金球形粉末表面包覆石蜡(PW),分析有机包覆层在凝胶注模过程中的作用机制及流变行为的影响,测定包覆前后不同粉末进行凝胶注模烧结后的组...     

置氢Ti6Al4V合金的微观组织演变规律

为研究置氢Ti6Al4V合金的高温加工改性机理,从微观组织的角度对合金进行了对比分析.利用OM、SEM、XRD等研究了置氢对Ti6Al4V合金变形前后微观组织演变的影响.研究结果表明:氢的加入不仅使置氢Ti6Al4V合金中β相比例明显增大,而且改变了α相与β相之间的电势差,在氢含量为0.3%~0.5%两相颜色将发生互换,氢含量增加到0.50%以上时,合金中将出现面心立方结构的δ氢化物;随氢含量的增加,合金超塑拉伸变形后的组织由α+β两相等轴晶粒变为粗大的β晶粒,造成α与β界面的协调能力下降,并改变了合金的变形机制.     

Damage evolution in Ti6Al4V–Al3Ti metal-intermetallic laminate composites

The crack propagation and damage evolution in metal (Ti6Al4V)-intermetallic (Al₃Ti) laminate composites were investigated. The composites (volume fractions of Ti6Al4V: 14%, 20% and 35%) were tested under different loading directions (perpendicular and parallel directions to laminate plane), to different strains (1%, 2%, 3%) and at different strain rates (0.0001 and 800–2000 s⁻¹). Crack densities and distributions were measured. The crack density increases with increasing strain, but decreases (at a constant strain) with increasing volume fraction of Ti6Al4V. Differences in crack propagation and damage evolution in MIL composites under quasi-static (10⁻⁴ s⁻¹) and dynamic (800–2000 s⁻¹) deformation were observed. The fracture stress does not exhibit significant strain-rate sensitivity; this is indicative of the dominance of microcracking processes in determining strength. Generally, the crack density after dynamic deformation is higher than that after quasi-static deformation. This is attributed to the decreased time for crack interaction in high-strain rate deformation. The effect of crack density, as quantified by a damage parameter, on elastic modulus and stress–strain relation were calculated and compared with experimental results.