新型TiNbTaZr合金的生物腐蚀性和细胞毒性(英文)

通过真空自耗电弧炉开发一种新型β钛合金Ti35Nb2Ta3Zr,其弹性模量仅为48GPa,探讨该合金的耐腐蚀性能和细胞毒性。在Ringer模拟体液中,通过测量开路电位、极化阻抗谱和极化曲线发现Ti35Nb2Ta3Zr的腐蚀性优于Ti6Al4V和Ti。细胞毒性试验证明Ti35Nb2Ta3Zr的生物相容性与目前临床常用的Ti6Al4V和Ti相当。因此,该新型β钛合金Ti35Nb2Ta3Zr具有良好的耐腐蚀性和生物相容性,未来作为生物材料具有广阔前景。     

Corrosion behavior of Ti‐xNb‐13Zr alloys in Ringer's solution

Ti‐6Al‐4V alloy has been widely used in restorative surgery due to its high corrosion resistance and biocompatibility. Nevertheless, some studies showed that V and Al release in the organism might induce cytotoxic effects and neurological disorders, which led to the development of V‐free alloys and both V‐ and Al‐free alloys containing Nb, Zr, Ta, or Mo. Among these alloys, Ti‐13Nb‐13Zr alloy is promising due to its better biomechanical compatibility than Ti‐6Al‐4V. In this work, the corrosion behavior of Ti, Ti‐6Al‐4V, and Ti‐xNb‐13Zr alloys (x = 5, 13, and 20) was evaluated in Ringer's solution (pH 7.5) at 37 °C through open‐circuit potential measurements, potentiodynamic polarization, and electrochemical impedance spectroscopy. Spontaneous passivity was observed for all materials in this medium. Low corrosion current densities (in the order of 10^?7 A/cm²) and high impedance values (in the order of 10⁵ Ωcm² at low frequencies) indicated their high corrosion resistance. EIS results showed that the passivating films were constituted of an outer porous layer (very low resistance) and an inner compact layer (high resistance), the latter providing the corrosion resistance of the materials. There was evidence that the Ti‐xNb‐13Zr alloys were more corrosion resistant than both Ti and Ti‐6Al‐4V in Ringer's solution.     

Corrosion behaviors of a new titanium alloy TZNT for surgical implant application in Ringer’s solution

A new near α-titanium alloy Ti12.5Zr2.5Nb2.5Ta (TZNT) for surgical implants was designed. The potentiodynamic technique was performed to investigate the corrosion behaviors of TZNT in Ringer's solution, and Ti6Al4V, Ti6Al7Nb, and TA2 were taken as comparison. The structure of the passive film was analyzed using an X-ray photoelectron spectrometer (XPS). The results indicate that TZNT possesses better corrosion resistance, when compared with Ti6Al4V, Ti6Al7Nb, and TA2. The passive film formed on the TZNT surface is composed of oxides, such as TiO2, ZrO2, Nb2O5, and Ta2O5. The elements Zr and Ta are rich, whereas Ti and Nb are poor in the passive film. The addi-tion of Zr, Nb, and Ta with relatively low electrochemical reaction potentials can reduce the anode activity and improve passive properties. Other than that, oxides such as ZrO2, Nb2O5, and Ta2O5 with the nobler equilibrium constants make the passive film more stable.     

Characterization of the Ti-10Nb-10Zr-5Ta Alloy for Biomedical Applications. Part 1: Microstructure, Mechanical Properties, and Corrosion Resistance

Ti-10Nb-10Zr-5Ta alloy was investigated as possible material candidate for replacing Ti6Al4V in medical applications. The alloy was prepared in a levitation melting furnace and characterized in terms of elemental and phase composition, microstructure, mechanical properties, and corrosion resistance in simulated body fluid and Fusayama Meyer artificial saliva solutions. The characteristics of the new alloy were compared to those of the Ti6Al4V alloy. The Ti-10Nb-10Zr-5Ta system was found to posses of a polyhedral structure consisting in α′ and β phases. X-ray structural analysis revealed a mixture of hexagonal α′ martensite (main phase, with grain size of about 21 nm) and β bcc phase. The Ti-10Nb-10Zr-5Ta alloy exhibited some better mechanical properties (Young modulus, tensile properties) and corrosion resistance (polarization resistance, corrosion current density, and corrosion rate), as compared to Ti6Al4V alloy.     

Composition and processing effects on the electrochemical characteristics of biomedical titanium alloys

The electrochemical behaviour of the Ti–13Nb–13Zr and Ti–6Al–4V ELI alloys with martensitic microstructures was investigated by polarization and electrochemical impedance spectroscopy (EIS) in Ringer’s solution. The impedance spectra were interpreted by a two time-constants equivalent circuit. Both investigated alloys showed high corrosion resistance, but the thin and uniform passive film on the Ti–6Al–4V ELI alloy surface was more protective. The inner barrier and outer porous layer were highly resistant and capacitive. However, thicker and more porous passive film on the Ti–13Nb–13Zr alloy surface may be beneficial for osteointegration. The suitable thermomechanical processing improved the corrosion resistance of Ti–13Nb–13Zr alloy.     

Corrosion behaviors of a new titanium alloy TZNT for surgical implant application in Ringer's solution

A new near α-titanium alloy Ti12.5Zr2.5Nb2.STa (TZNT) for surgical implants was designed. The potentiodynamic technique was per-formed to investigate the corrosion behaviors of TZNT in Ringer's solution, and Ti6A14V, Ti6A17Nb, and TA2 were taken as comparison. The structure of the passive film was analyzed using an X-ray photoelectron spectrometer (XPS). The results indicate that TZNT possesses better corrosion resistance, when compared with Ti6A14V, Ti6A17Nb, and TA2. The passive film formed on the TZNT surface is composed of oxides, such as TiO_2, ZrO_2, Nb_2O_5, and Ta_2O_5. The elements Zr and Ta are rich, whereas Ti and Nb are poor in the passive film. The addi-tion of Zr, Nb, and Ta with relatively low electrochemical reaction potentials can reduce the anode activity and improve passive properties. Other than that, oxides such as ZrO_2, Nb_2O_5, and Ta_2O_5 with the nobler equilibrium constants make the passive film more stable.     

Electrochemical characteristics of titanium based biomaterials in artificial saliva

In the last decade, new titanium alloys have been developed in different areas of dentistry, such as Ti6Al7Nb, Ti6Al2Nb1Ta1Nb, and Ti5Al2.5Fe. The aim of this study was to compare the Ti6Al7Nb, Ti6Al2Nb1Ta1Nb, Ti5Al2.5Fe, and Ti6Al4V alloys with the commercial titanium, regarding the corrosion resistance in artificial saliva. In the electrochemical estimations the polarization data are converted into instantaneous corrosion rate values (I_corr). The passivation properties were comparable for the four alloys. The EIS spectra are best fitted using an equivalent circuit (EC), which corresponds to the model of a two‐layer structure for the passive film. High impedance values (in the order of 10⁶ Ω cm²) were obtained from medium to low frequencies for all materials suggesting high corrosion resistance in artificial saliva. The electrochemical and corrosion behavior of Ti6Al4V is not affected on substituting vanadium with niobium, iron, molybdenum, and tantalum.     

Outstanding Mild Wear Performance of Ti–29Nb–14Ta–4.5Zr Alloy Through Subsurface Grain Refinement and Supporting Effect of Transformation Induced Plasticity

Metals and Materials International - The tribological performance of Ti–29Nb–14Ta–4.5Zr alloy against Ti–6Al–4V ELI was investigated for the mild condition, emphasized...     

合金元素对新型Co-Al-W合金热腐蚀行为的影响

研究了由γ'-Co₃(Al,W)相沉淀强化的新型钴基Co-Al-W 高温合金在800℃、75% Na₂SO₄+25% NaCl熔盐中的热腐蚀动力学及合金元素Mo、Nb、Ta和Ti对合金热腐蚀行为的影响。研究发现,2Mo、2Nb、 2Ta和2Ti合金比9.8W合金具有更好的抗热腐蚀能力,Mo和Ti对提高合金耐热腐蚀能力的效果比Ta和Nb显著。加入合金元素的合金热腐蚀膜由三层组成,即主要由Co氧化物CoO和Co₃O₄组成的腐蚀膜外层,由合金元素、Al、 Co及W复杂氧化物组成的中间过渡层和由Al、Co氧化物组成的腐蚀膜内层。随着腐蚀时间的增加,中间过渡层厚度逐渐增加,热腐蚀膜内、外层厚度变化不大,但内层致密性逐渐增加。     

Influence of Zr content on microstructure and mechanical properties of implant Ti–35Nb–4Sn–6Mo–xZr alloys

The influence of Zr content on the microstructure and mechanical properties of implant Ti–35Nb–4Sn–6Mo–xZr (x=0, 3, 6, 9, 12, 15; mass fraction) alloys was investigated. It is shown that Ti–35Nb–4Sn–6Mo–xZr alloys appear to have equiaxed single β microstructure after solution treatment at 1023 K. It is found that the grains are refined first and then coarsened with the increase of Zr content. It is also found that Zr element added to titanium alloys has both the solution strengthening and fine-grain strengthening effect, and affects the lattice parameters. With increasing the Zr content of the alloys, the strength increases, the elongation decreases, whereas the elastic modulus firstly increases and then decreases. The mechanical properties of Ti–35Nb–4Sn–6Mo–9Zr alloy are as follows: σ_b=785 MPa, δ=11%, E=68 GPa, which is more suitable for acting as human implant materials compared to the traditional implant Ti–6Al–4V alloy.     

Large gap joining of Ti–6Al–4V alloy with mixed powder interlayers

Abstract

Titanium based brazing alloys containing chromium, iron, copper, and nickel as β stabilisers have been studied for joining the titanium alloy Ti–6Al–4V. Two of these alloys were selected for use in producing large gap joints. The first brazing alloy, Ti–12Zr–14Cr–12Cu–12Ni (type 1), can be used to braze Ti–6Al–4V below its β transus temperature. Joints of thickness up to 150 μm can be made in a normal brazing cycle without prolonged holding. The interlayer consists of a β titanium alloy with no precipitation of intermetallic compounds. The second brazing alloy, Ti–12Zr–14Cr–6Fe–5Cu–5Ni (type 2), has to be brazed above the β transus temperature of Ti–6Al–4V. Its powders were mixed with pure titanium and Ti–6Al–4V powders and the mixture was used as the joining interlayer. Interlayers 5 mm in thickness were used to produce joints for microstructural examination and mechanical testing. It was found that residual pores in the interlayers were related to the amount of the brazing alloy in the interlayer. A fully dense interlayer could be obtained with 60 wt-% brazing alloy in the interlayer. The as bonded joints revealed tensile strength equal to 50% of that of the base metal. Diffusional treatment of the joints improved the joint efficiency to about 70%, compared with the base metal.     

The effects of spark anodizing treatment of pure titanium metals and titanium alloys on corrosion characteristics

This study evaluated the surface characteristics of oxide films on commercially pure titanium metals (CP-Ti; Grade 2 and Grade 3) and titanium alloy (Ti6Al4V and Ti6Al7Nb) samples formed by an anodic oxidation treatment, and investigated the effects of anodization on the corrosion characteristics. FE-SEM, XRD, and Raman spectroscopy were used to evaluate the micromorphology and crystalline structure of the oxide films. The corrosion resistance of the sample groups was evaluated using open-circuit potential and cyclic polarization tests. After anodic oxidation up to dielectric breakdown with the same electric current, 150-200 nm-sized pores were distributed homogeneously on pure titanium metal samples, partially occluded pores were observed on the Ti6Al4V alloy, and there was an inhomogeneous size and distribution of pores on the Ti6Al7Nb alloy. The titanium dioxide films formed through anodic oxidation contained a phase mixture of anatase and rutile. The cyclic polarization tests showed that all the tested sample groups were not susceptible to localized corrosion. The as-received and anodically oxidized CP-Ti grade 3 groups showed a higher corrosion resistance than the other groups. The mean E_corr values of the anodically oxidized sample groups, except for the anodized Ti6Al7Nb alloy, showed higher values than those of the respective as-received sample groups. In particular, the Ti6AL7Nb alloy showed a statistically higher E_corr value in the anodized group than in the as-received group (p < 0.05).     

Effects of the Zr and Mo contents on the electrochemical corrosion behavior of Ti–22Nb alloy

Ti–22Nb–xZr and Ti–22Nb–xMo (x = 0, 2, 4, 6, in atom percent) were prepared by an arc melting method. The alloys were solution‐treated at 1073 K for 1.8 ks followed by quenching them into ice water, and the electrochemical corrosion behavior in a 0.9% NaCl solution at 25 °C and neutral pH range of the solution‐treated alloys was evaluated by using electrochemical impedance spectroscopy, polarization curves and an equivalent circuit analysis. It was found that the microstructure of the solution‐treated Ti–22Nb alloy mainly contains β phase with small amount of α″ phase, and the addition of Zr or Mo to a Ti–22Nb alloy is efficient to stabilize the β phase. The resulting impedance parameters and passive current densities indicated that the corrosion resistance of the Ti–22Nb alloy was promoted significantly with the addition of Zr and Mo.     

金属材料在液态Al-Mg合金中的腐蚀行为

本文对 Fe、Ni、Mo、Zr、Nb、Cr、V、Ta 等金属或以它们为基的合金进行了抗液态 Al-Mg 合金腐蚀试验.材料的耐蚀性系借助金相观察测定溶解扩散层厚度和测定蚀损这两项指标来予以评定的。结果表明绝大多数金属及其合金均不耐液态 Al-Mg 合金的腐蚀,仅 Nb 和合金化程度低的Nb 基合金(如 Nb-2Al,Nb-1Cr)以及 Ta 显示山具有良好的耐蚀性.     

Characterization of the Ti-10Nb-10Zr-5Ta Alloy for Biomedical Applications. Part 2: Wettability, Tribological Performance and Biocompatibility

The Ti-10Nb-10Zr-5Ta alloy, prepared in a levitation melting furnace, was investigated as a possible candidate for replacing Ti6Al4V alloy in medical applications. The sessile drop method, pin-on-disc and in vitro tests were used to analyze wettability, wear resistance, and biocompatibility of the new alloy. The characteristics of the Ti-10Nb-10Zr-5Ta alloy were assessed in comparison to those of the Ti6Al4V alloy. The Ti-10Nb-10Zr-5Ta system was found to have hydrophilic characteristics with similar contact angle as the Ti6Al4V alloy. In all environments (deionized water, simulated body fluid and Fusayama Meyer artificial saliva), the friction coefficient showed a stable evolution versus sliding distance, being similar for both alloys. On overall, the wear resistance of Ti-10Nb-10Zr-5Ta alloy was lower than that of Ti6Al4V for all testing environments. The Ti-10Nb-10Zr-5Ta alloy exhibited good biocompatibility characteristics at in vitro test compared to Ti6Al4V alloy. The cell viability on Ti-10Nb-10Zr-5Ta surfaces was higher than the one observed on Ti6Al4V samples, regardless the number of days spent in osteoblast-like cells culture. A high degree of cell attachment and spreading was observed on both alloys.     

钛合金中原子迁移性质的第一原理研究

钛合金作为一种重要的航空材料,具有比强度高,耐蚀性好等优异性能,并具有一定的高温蠕变抗力。但是在更高温度下,有限的蠕变抗力限制了钛合金的进一步应用。实验研究表明,钛合金稳态蠕变过程蠕变激活能与合金的表观扩散激活能非常接近,说明原子的扩散与蠕变过程密切相关。本文采用第一性原理的方法,计算了钛合金中常见的杂质及合金原子的迁移能垒。结果表明,对以空位机制扩散的合金原子,其在基面内迁移的能垒从高到低为Al、V、Ti、Sn、Ta、Mo、Nb、Zr,面间原子迁移由难到易为Al、Sn、V、Ti、Ta、Mo、Nb、Zr。以间隙机制迁移的Co、Fe、Ni迁移能垒较低,与实验观测到的这些原子为快扩散原子相符。     

Relationship between phase composition and corrosion resistanceof Ni-Ti-Nb based shape memory alloys

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Corrosion behaviour of a new Ti‐6Al‐2Nb‐1Ta alloy in various solutions

A new Ti‐6Al‐2Nb‐1Ta alloy was obtained for to satisfy the mechanical and anticorrosion requirements in neutral corrosive environment. The corrosion behaviour of this new Ti‐6Al‐2Nb‐1Ta alloy in 0.1 M Na₂SO₄, 3% NaCl solutions and synthetic sea water was studied in this paper, using potentiodynamic and linear polarisation method, electrochemical impedance spectroscopy (EIS) and monitoring of the open circuit potentials. The structure of the alloy represents an α + β uniform structure with un‐oriented grains. From the potentiodynamic polarisation curves it resulted that the studied alloy is self‐passivated in all three solutions having a very good and very easy tendency to passivation. The most favourable values of the electrochemical parameters were registered in 0.1 M Na₂SO₄ solution due to its reduced corrosivity. EIS measurements proved the improvement of the passive layer resistance with the immersion time. An electric equivalent circuit with two time constants was fitted. The values of the polarisation resistances showed very good protective capacities which improved in time. The open circuit potentials have the general tendency to ennoble in time, suggesting the thickening of the passive films and the increase of their protective capacities.     

The site occupancies of alloying elements in TiAl and Ti3Al alloys

The site occupancies of V, Cr, Mn, Fe, Ni, Zr, Nb, Mo, Ta, Ga and Sn (1–5 at.%) in TiAl alloys with different compositions, and in Ti₃Al with the compositions of Ti–26 at.%Al–(1–2 at.%)X, were measured by the atom location channelling enhanced microanalysis (ALCHEMI) method. For TiAl alloys, the results show that Zr, Nb and Ta atoms invariably occupy Ti sites, while Fe, Ni, Ga and Sn atoms occupy Al sites, the alloy composition having no significant influence on their site preference. By contrast, the site preference of V, Cr, and Mn changes considerably with alloy composition (the Ti/Al ratio in particular), the probability of these elements substituting for Ti decreasing in the above order. For quaternary Ti–Al–V–Cr alloys, the site occupancies of V and Cr do not show much mutual influence. In general, with increasing atomic number, elements in the same period show increasing tendency to substitute for Al, as is the tendency to substitute for Ti for elements in the same group of the periodic table. For Ti₃Al alloys, Ga and Sn atoms occupy Al sites, while V, Cr, Mn, Zr, Nb, Mo and Ta atoms occupy Ti sites, the site preference of V, Cr, Mn and Mo in TiAl alloys being different from that in Ti₃Al. The experimental results are interpreted in terms of a Bragg–Williams-type model and bond-order data obtained from electronic structure calculation. Qualitative agreement between the model and measurements is reached.     

The relation between electrochemical tests and in vitro evaluation of titanium alloy biocompatibility

In this paper, the electrochemical behaviour of the titanium and Ti‐6Al‐7Nb alloy in artificial saliva (Tani&Zucchi and Carter–Brugirard), ion release tests and in vitro biocompatibility of human osteoblasts (HOB) were studied. Titanium and its implant Ti‐6Al‐7Nb alloy present self‐passivation and very stable passive films in Tani&Zucchi artificial saliva of pH = 2.5; 5; 6.7; 9; the total quantity of ions released in the artificial saliva and corrosion rates are very low, proving a very good corrosion resistance and very low toxicity. In undoped and doped Carter–Brugirard saliva, the open circuit potentials have highly electropositive values, denoting passive state and good stability; the open circuit potential gradients, simulating the non‐uniformity of the saliva composition, show very low values, no danger for the implant integrity. The in vitro cytotoxicity of Ti‐6Al‐7Nb alloy was evaluated on the basis of cell morphology and cell viability. The results obtained revealed a high biocompatibility between HOB and Ti‐6Al‐7Nb alloy.