外科植入物用钛合金研究进展和标准化现状

介绍了外科植入物用钛的研究：（1）纯钛，Ti-6Al-4V合金；（2）Ti-6Al-7Nb合金；（3）新型β钛合金（Ti-13Nb-13Zr,Ti-12Mo-6Zr-2Fe,Ti-15Mo-2.8Nb-0.2Si合金）；（4）Ti-Ni合金，概述了其研究进展，这些合金的性能特点，应用和标准化现状。     

外科植入物用新型TAMZ合金的生物学性能（Ⅰ）

新型医用钛合金是当前生物医用材料的一个重要领域 ,西北有色金属研究院同第四军医大学合作 ,依据我国临床上使用的金属材料现状和医用钛合金存在的问题 ,以外科植入物为目标 ,设计并研制出了具有我国知识产权的新型医用钛合金 TAMZ(Ti- 2 .5Al- 2 .5 Mo- 2 .5 Zr) ,与目前通用的医用 Ti-6 Al- 4V合金相比 ,新合金在生物相容性、综合力学性能、工艺成型性等方面具有显著的优越性 ,是比较理想的生物医用钛合金。TAMZ合金主要用于人体内硬组织的修复和替换 ,该合金已于 2 0 0 0年 7月通过陕西省组织的技术鉴定 ,同时获得国家发明专利授…     

我国首次颁布外科植入物用钛合金加工材的国家标准

钛具有比强度高、抗蚀性与人体相容性好等特点,作为人体植入物已应用多年,在国内外并有大量的成功实例。在植入物标准化方面,欧美发达国家早已建立了相应的钛植入物用材料标准系列,其中包括四种不同强度的纯钛、Ti-6Al-4V、Ti-5Al-2.5Sn、Ti-5Al-2.5Fe等以及新研制的一些新型钛合金。     

外科植入物用钛合金Ti—6Al—7Nb的研究

在工业生产条件下制备了外科植入物用Ti-6Al-7Nb钛合金,并对其化学组成、机械性能和微观组织进行了研究。Ti-6Al-7Nb合金的成分和性能完全达到国际标准ISO5832－11和美国ASTMF1295标准要求,其组织为大量α相＋少量β转相。     

表面机械处理对Ti-54M合金高周疲劳性能的影响

Ti-54M合金是美国由TIMET（Ti-5A14V-0．6Mo-0．4Fe）合金发展而来的一种α＋β两相钛合金,其切削加工性（切割速度和切割工具寿命）可与Ti-6A14V合金相媲美。该合金用电子束冷床炉单次熔炼制得,可以混合少量的Ti-6A1-4V合金或其他含有元素Mo、V和Fe的合金。除了原材料的弹性性能之外,Ti-54M合金的切削加工性能优于Ti-6Al-4V合金。     

热处理制度对Ti-3Al-2.5V钛合金带材组织及性能的影响

Ti-3Al-2.5V合金是一种近α,α-β型的低合金成分的合金,在管材制品中,它是最适合,用的最广泛的钛合金,本文研究了在20辊可逆式冷轧机生产出的0.254mm成品Ti-3Al-2.5V钛合金带材在硬态及620℃～740℃热处理制度下的显微组织与性能,优选出合适的热处理温度范围为620～660℃。     

显微组织及模拟生物体环境对生物体用Ti-5Al-2．5Fe合金疲劳裂纹扩展特性的影响

以整形外科为中心的金属系生物体用材料有不锈钢(Sus316L)以及Co-Cr-Mo合金，最近耐蚀性和生物体相容性好的钛及钛合金使用量增加。由于Ti-6Al-4V中含有对人体有毒的V元素，为此开发了用铁或铌置换B稳定化元素V的Ti-5Al-2．5Fe和Ti-15Al-7Nb合金，合金分别在ISO和ASTM及ISO标准中登录，期待扩大在生物体上使用。但是对两合金的各种特性研究不够，作为生物体用的重要特性之一的疲劳性能也不例外。     

近β型生物医用钛合金在磷酸缓冲液中的电化学行为

<正>根据钛合金在室温下合金元素以及相组成的不同,可以将其分为α型、β型以及α+β型三大类。其中,工业纯钛(α型)、Ti-6Al-4V合金(α+β型)在牙科植入物方面已经有多年的应用。但是,由于这两种合金的弹性模量较高、耐磨性较差,并且Ti-6Al-4V合金在使用过程中释放的铝离子和钒离子会对人体造成伤害,因此,近年来科研工作者将生物医用钛合金的研究重点放在了开发新型β型生物医     

Ti-6Al-4V合金表面改性技术

Ti-6Al-4V合金作为一种重要的钛合金,其使用量占到了钛合金总使用量的75%～85%,但其耐磨性差、阻燃性差、疏水疏冰性能差、生物相容性不理想等性能缺陷在一定程度上限制了其在某些领域中的应用。首先对Ti-6Al-4V合金在各个领域应用时,其性能缺陷的表现形式及危害进行了概述,然后介绍了目前改善Ti-6Al-4V合金性能缺陷所普遍采用的以及具有创新性的表面改性技术,评述了部分表面改性技术的优缺点,最后提出了需对Ti-6Al-4V合金表面改性技术进一步研究的方向。     

用氧化钙系铸型铸造的牙科用TNTZ钛合金的力学性能

β钛合金Ti-29Nb-13Ta-4．6Zr（TNTZ）具有良好的强度一延性匹配，期待用于下一代牙科镶嵌材料，但其熔点高达2300K，明显高于低间隙Ti-15Al-4V ELI合金（1900K）。用原有氢化镁铸型铸造TNTZ合金时，合金表面易被烧伤，为此必须开发在高温领域稳定的铸型材料。已研究了用氧化钙系材料的铸型，可以制备牙科用TNTZ精密铸件，但采用这种铸型的TNTZ铸件的力学性能尚不清楚。     

生物医用Ti6Al4V合金粉末注射成形工艺研究

钛及钛合金具有高比强度、低弹性模量、优良的耐蚀性和绝佳的生物相容性,但较差的加工性能大大限制了其应用范围。钛及钛合金金属粉末注射成形工艺克服了机加工、模压等传统加工工艺的缺点,结合传统粉末冶金和注塑成型的优势,实现了结构复杂的钛及钛合金产品低成本、大批量近净成形,提高了材料利用率。本文利用水溶性黏结剂和粉末粒度为16 μm和22 μm的商用球形Ti6Al4V合金粉制备了注射料和相应的试样,通过实验确定了气氛热脱黏结合真空烧结的最佳工艺,基于该工艺制备得到了两种注射料的烧结试样。结果表明:粉末粒度为16 μm注射料烧结件杂质含量未能满足外科植入用金属注射成形Ti6Al4V组件标准;粉末粒度为22 μm注射料烧结件物理化学性能如下,极限拉伸强度880 MPa,屈服强度830 MPa,延伸率13.2%,相对密度96.8%,氧质量分数为0.195%,氮质量分数为0.020%,碳质量分数为0.022%,该试样整体性能满足外科植入用金属注射成形Ti6Al4V组件标准。     

Review of effect of oxygen on room temperature ductility of titanium and titanium alloys

Abstract

Room temperature tensile ductility is an important property of titanium (Ti) and titanium alloys for structural applications. This article reviews the dependency of tensile ductility on oxygen for α-Ti, (α+β)-Ti and β-Ti alloys fabricated via traditional ingot metallurgy (IM), powder metallurgy (PM) and additive manufacturing (AM) or three-dimensional printing methods and recent advances in understanding the effect of oxygen on ductility. Seven mechanisms have been discussed based on case studies of individual titanium materials reported in literature. The dependency of ductility on oxygen is determined by both the composition and microstructure of the titanium alloy. For Ti–6Al–4V (wt-%), as sintered Ti–6Al–4V shows a critical oxygen level of about 0·33 wt-% while additively manufactured Ti–6Al–4V exhibits different critical levels ranging from about 0·22% to well above 0·4% depending on microstructure. Rare earth (RE) elements are effective scavengers of oxygen in titanium materials even just with a small addition (e.g. 0·1 wt-%), irrespective of the manufacturing method (IM, PM and AM). High cycle fatigue experiments revealed no initiation of fatigue cracks from the resulting RE oxide particles over the size range from submicrometres to a few micrometres. A small addition of RE elements offers a practical and affordable approach to mitigating the detrimental effect of oxygen on ductility.     

Effect of Nanosecond Laser-Textured Ablation on Performance of Ti6Al4V Alloy Prepared by Composite Nitriding Process

As a widely used orthopedic implant, titanium alloy will face the corrosion of body fluid in human body. In addition, the wear of implants and bones in human body will also reduce the service life of implants. To improve the wear resistance and corrosion resistance of biological titanium alloy, Ti6Al4V alloy was modified by plasma nitriding and plasma-enhanced chemical vapor deposition (PN + PECVD) composite process, and then samples were ablated by nanosecond laser to form a regular surface texture. The textured Ti6Al4V and PN + PECVD samples marked as Ti6Al4V-T and PN + PECVD-T samples. The microstructure and phase composition of the samples before and after modification were observed by scanning electron microscope (SEM), energy-dispersive spectrometer (EDS) and X-ray diffraction (XRD). It was found that after PN + PECVD process, a TiN film with a thickness of 2 μm was formed on the surface of Ti6Al4V. The surface texture of Ti6Al4V-T sample was regular, but the PN + PECVD-T sample texture was wide and shallow irregular after nanosecond laser ablation. The Ti–O and Ti–N–O non-stoichiometric compounds appeared on the samples after nanosecond laser ablation. Through the wear and electrochemical corrosion test in SBF, it was found that PN + PECVD sample had the best wear resistance and corrosion resistance. The wear resistance and corrosion resistance of Ti6Al4V-T and PN + PECVD-T samples were much better than that of Ti6Al4V substrate. The results show that, nitrogen oxides formed on the surface had higher microhardness and surface density, which was beneficial to improve the wear resistance and corrosion resistance of implants.

     

Surface films and stress-corrosion cracking in Ti−Al alloys

The characteristics of film growth on a series of binary Ti?Al alloys and on two commercial titanium alloys have been examined by ellipsometry and correlated with the velocity of stress-corrosion cracking in these alloys as a function of both applied potential and pH of the environment. It has been found that factors which stimulate film growth,i. e. high pH and the application of anodic potentials, reduce the velocity of cracking while factors which restrict film formation, such as increasing the aluminum content of the alloy or the presence of Ti₃Al, facilitate cracking. These studies indicate that the occurrence of stress-corrosion cracking in Ti?Al alloys is confined to an environmental regime in which surface films are relatively thin.     

Dry Sliding Wear Behavior of Ti–6Al–4V Implant Alloy Subjected to Various Surface Treatments

Titanium alloys are extensively used in various fields of engineering, medicine, aerospace, marine due to their excellent mechanical properties. Their usage is more pronounced today in the field of biomedical implants due to superior biocompatibility, corrosive resistance and high strength. However, titanium alloys have poor wear resistance due to high coefficient of friction. Poor abrasive wear resistance results in the formation of wear debris at the implant area causing toxicity, inflammation and pain. Surface treatment of the implant alloy through heat treatment, application of protective coatings and introduction of compressive residual stresses by shotpeening are some of the methods to mitigate wear of the implant alloy. In this work Ti?C6Al?C4V implant alloy is treated under various conditions of heat treatment and shotpeening operations on a pin on disc wear testing machine. Scanning electron micrograph along with energy dispersive spectrometry analysis is done to authenticate the experimental results obtained during the wear testing procedure.     

多组元钛合金电子束冷床炉熔炼挥发规律研究

利用电子束冷床炉(EB炉)一次熔炼制备TC4、Ti6242、TA15钛合金铸锭,采用Langmuir定律对熔炼过程中Al、Sn、Zr、Mo等元素的挥发规律做了简要的数值分析,并与实际挥发规律进行了对比分析。结果表明:EB炉熔炼TC4、Ti6242、TA15钛合金过程中,Al元素在3种合金中的挥发率有所不同,挥发率由大到小顺序为TC4>Ti6242>TA15;Al元素是TC4钛合金中主要的挥发元素;Ti6242钛合金中,Al、Sn元素之间存在联合挥发的问题;TA15钛合金中,Al、Zr元素之间亦存在联合挥发的问题,Al元素带动了Zr元素(难挥发元素)的挥发。     

粉末冶金Ti6Al4V合金的研究

采用Ti粉、AlV中间合金粉,通过模压和真空烧结制备了Ti6Al4V合金,并通过随后的锻造和热处理来改变其组织和性能.通过金相显微镜、X射线衍射(XRD)仪、扫描电镜(SEM)及力学性能检测等分析手段,系统研究了压制压力对Ti6Al4V烧结体密度的影响,以及试样状态(烧结态及烧结淬火态)、锻造温度、淬火温度及时效温度等工艺参数对粉末冶金Ti6Al4V合金组织和性能的影响.结果表明:通过模压和烧结可制备出相对密度达97.4%的Ti6Al4V合金;Ti6Al4V烧结态及烧结淬火态合金经过锻造后,相对密度接近100%;通过不同热处理工艺得到不同组织和性能,能获得等轴组织,其α晶粒尺寸在5μm左右.     

加工及热处理对Ti5Zr6Mol5Nb钛合金组织和性能的影响

以新型近β型医用钛合金Ti-5Zr-6Mo-15Nb（TLE）铸锭为实验原料,通过开坯、锻造、轧制、热处理等多道工序制成板材和棒材。分析了不同加工工艺及热处理制度对合金组织与性能的影响。结果表明：TLE合金具有较高的强度、较低的弹性模量、优良的塑韧性与疲劳性能,冷热加工性能好;合金经过适当的固溶与时效处理后可获得良好的综合力学性能匹配,特别适合充当外科植入物材料使用。     

稀土La对粉末冶金钛合金组织和力学性能的影响

在Ti-Fe-Mo合金中以LaH2和LaB6两种形式引入稀土La,制备含La的粉末冶金钛合金,研究La的添加量对钛合金烧结行为以及组织与力学性能的影响,探讨合金中La的存在形式及其在烧结过程中的作用机理。结果表明,钛合金相对密度随LaH2添加量(质量分数)的增加而升高,当LaH2的添加量达到0.6%后,钛合金的相对密度不再发生明显变化;但随着LaB6添加量的增加先升高后降低,在LaB6添加量为0.15%时出现峰值。添加LaH2的钛合金中,稀土元素主要以La2O3颗粒的形式存在,随La含量增加,颗粒发生长大;而在添加LaB6的合金中,烧结反应产物主要是纤维状的TiB、具有规则外形的La2O3颗粒以及含Ti和O的富La絮状颗粒。随LaH2和LaB6的添加量增加,合金的室温抗拉强度和伸长率均先升高后降低。LaH2的添加量达到0.6%时出现强度峰值,添加量达到0.3%时出现伸长率的峰值;而LaB6的添加量达到0.15%时抗拉强度和伸长率均出现峰值。     

Cytokeratin expression in human oral gingival epithelial cells: in vitro regulation by titanium-based implant materials

To evaluate whether cytokeratin expression in human oral epithelial cells could be influenced by implant materials used in dental surgery, passaged human oral gingival epithelial cells were seeded on commercially pure titanium (CP-Ti) or on Ti6Al4V titanium alloy. Confluence was achieved after about 15 days on both substrates. Cells formed at that time, an organized layer of densely packed polygonal cells, and harbored a filamentous cytokeratin network typical of epithelial cells. Immunochemistry and immunoblot analysis were used to detect modifications of the amount of individual CK polypeptides (CK7, 8, 13, 18 and 19) in function of the culture substrate. Results showed that the level of CK8, CK18 and CK19 expression was not altered whatever the culture substrate used. The expression of CK13 was reduced in epithelial cells cultured on the titanium alloy, as compared with commercially pure titanium. Conversely, the level of CK7 was higher on the Ti6Al4V alloy than on commercially pure titanium. This study suggests that titanium-based implant materials could influence differently the phenotype of oral gingival epithelial cells.