Glass formation and properties of Ti-based bulk metallic glasses as potential biomaterials with Nb additions

Ti_(47)Cu_(38-x)Zr_(7.5)Fe_(2.5)Sn_2Si_1Ag_2Nb_x (x=0, 1,2; at%) bulk metallic glasses (BMGs) with superior biocorrosion resistance were synthesized by copper mold casting. Although the minor addition of Nb to the Ti-CuZr-Fe-Sn-Si-Ag BMG slightly decreases the glass-forming ability (GF A), the Nb-bearing Ti-based alloys could be casted in a bulk glassy rod form with diameters up to3 mm. It is found that partial substitution of Cu with Nb is effective on enhancing the bio-corrosion resistance of the Ti-based BMG. Potentiodynamic polarization measurements show that Nb addition to Ti-based BMG leads to higher open-circuit potential and pitting potential as well as lower passive current density in Hank's solution. Electrochemical impedance spectroscopy (EIS) results indicate that with Nb content increasing, the charge transfer resistance values of the Ti-based BMGs become larger,demonstrating that the surface oxide films are more protective. The Nb-bearing Ti-based BMGs also exhibit good in vitro biocompatibility comparable to that of Ti-6Al-4V alloy. The enhanced bio-corrosion resistance, excellent in vitro biocompatibility and good mechanical properties of the Nb-bearing Ti-based BMGs are favorable for biomedical applications.     

Enhanced Mechanical Properties,Corrosion Behavior and Bioactivity of Ti-based Bulk Metallic Glasses with Minor Addition Elements

In this research, corrosion behavior, mechanical properties and bioactivity of Ti–Zr–Cu–Pd–Sn bulk metallic glasses with minor addition of Au, Pt, Nb or Ta elements were investigated. The results revealed that minor additions of the elements were beneficial to enhancing mechanical properties and corrosion resistance of Ti-based bulk metallic glasses.Minor addition of the element(especially with Nb and Ta addition) results in the improvement in plastic deformation ability due to the existing of nanoparticles with a size smaller than 10 nm in glassy matrix, inhibiting the deformation of the shear bonds. Enrichments of Ti and Zr elements in oxide layer were responsible for high corrosion resistance. The bioactivity of Ti-based bulk metallic glasses was also investigated. The best combination of large plastic deformation ability, good corrosion resistance and bioactivity in Ti_(40)Zr_(10)Cu_(33)Pd_(14)Sn_2Ta_1 BMG was obtained.     

Synthesis,properties and XPS analysis of Cu-,Ni-,Ti-based metallic glasses

Metallic glasses（MG）represent an interesting group of materials as they possess outstanding physical,chemical and mechanical properties compared to their crystalline counterparts.This paper reviews the synergistic influence of Ni and Nb elements on thermal stability of supercooled liquid and corrosion resistance of as-cast Cu-Zr（Hf）-Ti-Ni-Nb bulk metallic glasses（BMGs）.Additionally,in-situ second phase reinforced Cu-based BMG composites with high corrosion resistance and excellent mechanical properties are investigated.On the other hand,this paper reports the development of ultra-high corrosion resistant Ni-based metallic glasses at high temperatures for their potential applications.Corrosion resistance and XPS analysis of the Nifree Ti-based BMG are also introduced.     

Formation and properties of Ti-based Ti–Zr–Cu–Fe–Sn–Si bulk metallic glasses with different (Ti + Zr)/Cu ratios for biomedical application

Ti-based Ti–Zr–Cu–Fe–Sn–Si bulk metallic glasses (BMGs) free from highly toxic elements Ni and Be were developed as promising biomaterials. The influence of (Ti + Zr)/Cu ratio on glass-formation, thermal stability, mechanical properties, bio-corrosion resistance, surface wettability and biocompatibility were investigated. In the present Ti-based BMG system, the Ti₄₇Zr_7.5Cu₄₀Fe_2.5Sn₂Si₁ glassy alloy exhibited the highest glass forming ability (GFA) corresponding to the largest supercooled liquid region, and a glassy rod with a critical diameter of 3 mm was prepared by copper-mold casting. The Ti-based BMGs possess high compressive strength of 2014–2185 MPa and microhardness of 606–613 Hv. Young's modulus of the Ti₄₇Zr_7.5Cu₄₀Fe_2.5Sn₂Si₁ glassy alloy was about 100 GPa, which is slightly lower than that of Ti–6Al–4V alloy. The Ti₄₇Zr_7.5Cu₄₀Fe_2.5Sn₂Si₁ glassy alloy with high GFA exhibited high bio-corrosion resistance, and good surface hydrophilia and cytocompatibility. The mechanisms for glass formation as well as the effect of (Ti + Zr)/Cu ratio on bio-corrosion behavior and biocompatibility are discussed.     

Corrosion behaviour of porous Ni-free Ti-based bulk metallic glass produced by spark plasma sintering in Hanks' solution

Porous bulk metallic glasses (BMGs) are promising biomedical materials to be used for surgical implants. Here we report on successful formation of porous Ni-free Ti-based BMGs with a diameter exceeding 15 mm by spark plasma sintering the mixture of the gas-atomized Ti-based (Ti₄₅Zr₁₀Cu₃₁Pd₁₀Sn₄) glassy alloy powder and solid salt powder, followed by leaching treatment into water to eliminate the salt phase. Corrosion behaviour of the produced porous Ti-based BMGs was investigated in Hanks' solution. The potentiodynamic polarization curves showed that the anodic current density in the porous Ti-based BMGs slowly increased during anodic polarization, suggesting the crevice corrosion.     

Influence of Minor Addition of In on Corrosion Resistance of Cu-Based Bulk Metallic Glasses in 3.5% NaCl Solution

研究了铜基块体非晶合金Cu55-x Zr37Ti8Inx(x=0～5,at%)及Cu61-x Zr34Ti5Inx(x=0～3,at%)在质量分数3.5%NaCl溶液中的耐蚀性。极化曲线结果表明,在铜基非晶合金中添加In元素能明显提高合金的腐蚀电位、降低腐蚀电流密度,即能明显提高耐蚀性。含In的铜基块体非晶合金的腐蚀电流密度(Icorr)值比不含In的铜基块体非晶合金低约1个数量级。而且,利用In适量取代Cu可进一步提高耐蚀性。但过量添加In不利于形成富Zr保护膜,从而降低合金的耐蚀性。     

Mechanical properties of ZrCuTi thin film metallic glass with high content of immiscible tantalum

The ZrCuTi thin film metallic glasses (TFMGs) with immiscible Ta were successfully fabricated via co-sputtering. The glass forming composition for ZrCuTi-Ta TFMGs ranges from 0 to ~ 75 at.% of immiscible Ta, distinctly different from bulk metallic glasses (BMGs). When Ta content is over 75 at.%, the amorphous TFMG structure gradually transforms to nanocrystalline β-Ta. The mechanical properties are strongly influenced by Ta content. The elastic modulus remains nearly constant over 0-50 at.% Ta, and increase rapidly over 50-100% Ta. The key factor appears to be the population of the Ta-Ta strong bonds. The highest elastic modulus and hardness up to ~ 140 GPa and 10 GPa, respectively, of the Ta-rich TFMGs, much higher than the Zr-, Cu- and Ti-based amorphous alloys, might be useful for applications.     

Dual phase metallic glassy composites with large-size and ultra-high strength fabricated by spark plasma sintering

Two-phase bulk metallic glasses (BMGs) have attracted increasing interest since phase separation might produce metallic glasses with new physical and mechanical properties. In this study, we fabricated the dual phase glassy BMG composites by a spark plasma sintering process using a mixed powder of the gas-atomized Ni-based and Fe-based metallic glassy alloy powders. The thermal stability, microstructure, mechanical and magnetic properties of the obtained dual-phase glassy composites were investigated. The dual-phase glassy composites exhibited ultra-high strength and good soft magnetic properties which satisfy large-size requirements.     

Effects of Nitrogen on the Glass Formation and Mechanical Properties of a Ti-Based Metallic Glass

Effects of nitrogen addition on glass formation and mechanical properties of the Ti42.5Cu40Zr10Ni5Sn2.5metallic glass were systematically investigated. It was found that a small amount of nitrogen addition facilitated the glass formation by suppressing formation of the competing eutectic structure. Unlike large atomic size elements such as Hf and Pd which usually deteriorate specific strength, nitrogen can also increase the specific strength of the current Ti-based BMGs. The results are not only helpful for understanding glass-forming ability in general, but also useful in developing cost-effective, high-performance Ti-based bulk metallic glasses with enhanced glass-forming ability.     

非晶及纳米结构钛合金研究进展

综述了钛基大块非晶的成分-非晶形成能力的对应关系，总结了已知的钛基大块非晶的一次结晶相及力学性能，并阐述了钛基大块非晶的塑性变形机制，以及造成低塑性的因素和改善塑性的方法，着重介绍了铸造纳米结构钛合金的成分、组织和力学性能。通过精巧的成分设计，结合金属模铸造技术，制备出了直径小于5mm，并具有微米尺度β-Ti（M）一次树枝晶相＋纳米尺度棒状β-Ti／γ-TiCu共晶结构的复合组织，其中棒状β-Ti相尺寸在30nm～300nm范围；γ-TiCu共晶基体相由小于10nm的晶粒或亚晶粒组成，这种多层次纳米结构的钛合金具有高强度，同时县有明显的延伸性。     

Electrochemical properties and surface analysis of Cu–Zr–Ag–Al–Nb bulk metallic glasses

The electrochemical properties and surface characteristics of Cu–Zr–Ag–Al–Nb bulk metallic glasses (BMGs) were investigated. The alloys exhibit excellent corrosion resistance after immersion in 1N H₂SO₄ and 1N NaOH. The corrosion rates of the alloys in chloride-ion-containing solutions significantly decrease by alloying with Nb element. The formation of Zr- and Nb-enriched surface films could be responsible for the high corrosion resistance.     

Thermal stability,mechanical properties and corrosion behavior of a Mg–Cu–Ag–Gd metallic glass with Nd addition

By the minor addition of Nb to a Mg-Cu-AgGd alloy,a Mg-Cu-Ag-Gd-Nb bulk metallic glass(BMG)with improved thermal stability and corrosion resistance as well as good mechanical properties was developed.Mg_(54)Cu_(26.5)Ag_(8.5)Gd_(11_x)Nb_x(x = 0,1) BMGs with a diameter of 2 mm were fabricated by copper-mold casting.The Mg_(54)Cu_(26.5)Ag_(8.5)Gd_(10)Nb_1 BMG exhibits enlarged supercooled liquid region of 58 K.Electrochemical measurements indicate that the addition of Nb improves the corrosion resistance of the Mg-based BMG in NaCl solution evidenced by the increased corrosion potential,though no significant effect of Nb on the corrosion behavior of the BMG in NaOH solution is observed.The Mg-Cu-Ag-GdNb BMG also shows high compressive strength up to890 MPa and elastic strain of about 1.9%.     

Preparation and electrochemical characterization of Ti-based amorphous metallic glass with high strength

Ti-based amorphous metallic glasses have excellent mechanical, physical, and chemical properties, which is an important development direction and research hotspot of metal composite reinforcement. As a stable, simple, efficient, and large-scale preparation technology of metallic powders, the gas atomization process provides an effective way of preparing amorphous metallic glasses. In this study, the controllable fabrication of a Ti-based amorphous powder, with high efficiency, has been realized by using gas atomization. The scanning electron microscope, energy-dispersive spectrometer, and X-ray diffraction are used to analyze surface morphology, element distribution, and phase structure, respectively. A microhardness tester is used to measure the mechanical property. An electrochemical workstation is used to characterize corrosion behavior. The results show that as-prepared microparticles are more uniform and exhibit good amorphous characteristics. The mechanical test shows that the hardness of amorphous powder is significantly increased as compared with that before preparation, which has the prospect of being an important part of engineering reinforced materials. Further electrochemical measurement shows that the corrosion resistance of the as-prepared sample is also significantly improved. This study has laid a solid foundation for expanding applications of Ti-based metallic glasses, especially in heavy-duty and corrosive domains.     

Enhancement on GFA and mechanical properties of Ni-based bulk metallic glasses through Fe addition

Bulk Ni_76-xFe_xP₁₄B₆Ta₄ (x = 10, 20, 30, all in at.%) glassy alloy rods with diameters of 1.5–3.0 mm are synthesized by combining fluxing treatment and J-quenching technique, and the effects of Fe substitution for Ni on the glass forming ability (GFA), thermal stability, mechanical properties, and corrosion resistance of the present Ni-based bulk metallic glasses (BMGs) have been studied systematically in this work. It is found that the appropriate substitution of Fe for Ni can greatly enhance the GFA of the present Ni-based alloys, and the critical diameter for fully glass formation gets to the maximum value of 3.0 mm when the substitution content of Fe for Ni is 20 at.%. The corrosion tests show that the substitution of Fe for Ni causes a certain reduction of the corrosion resistance of the present Ni-based BMGs, but the corrosion current densities in both 1 M NaCl and 1 M HCl solutions are below the order of magnitude of 10⁻⁵ A/cm² and the corrosion rate in1 M HCl solution is in the order of magnitude of 0.1 mm/year, still exhibiting a good corrosion resistance. The present Ni-based BMGs exhibit a compressive strength of more than 2.6 GPa and, more significantly, the substitution of Fe for Ni greatly enhances the compressive plasticity of the present Ni-based BMGs and the compressive plastic strain gets up to 6.6% when 20 at.% of Ni is substituted by Fe. This work indicates that the GFA and mechanical properties of Ni-based BMGs can be enhanced significantly through the Fe addition.     

Zr–(Cu,Ag)–Al bulk metallic glasses

In this paper, we report the formation of a series Zr–(Cu,Ag)–Al bulk metallic glasses (BMGs) with diameters at least 20 mm and demonstrate the formation of about 25 g amorphous metallic ingots in a wide Zr–(Cu,Ag)–Al composition range using a conventional arc-melting machine. The origin of high glass-forming ability (GFA) of the Zr–(Cu,Ag)–Al alloy system has been investigated from the structural, thermodynamic and kinetic points of view. The high GFA of the Zr–(Cu,Ag)–Al system is attributed to denser local atomic packing and the smaller difference in Gibbs free energy between amorphous and crystalline phases. The thermal, mechanical and corrosion properties, as well as elastic constants for the newly developed Zr–(Cu,Ag)–Al BMGs, are also presented. These newly developed Ni-free Zr–(Cu,Ag)–Al BMGs exhibit excellent combined properties: strong GFA, high strength, high compressive plasticity, cheap and non-toxic raw materials and biocompatible property, as compared with other BMGs, leading to their potential industrial applications.     

添加微量Mo对铜基块体非晶合金耐蚀性的影响

采用动电位极化和交流阻抗谱技术(EIS)研究了(Cu47Zr11Ti34Ni8)100-x Mox(x=0,2)块体非晶合金在1mol/L H2SO4溶液中的室温电化学行为.结果表明,x=2的钝化膜破裂电位(Eb)显著上升,致钝化电位(E0)与维钝电流密度(ip)明显减小.这主要是由于在稳定的钝化区内,微量Mo的添加增加了基体合金中的"氧空位"和表面活性,抑制了阴离子空位在金属/表面膜(M/F)界面上的形成,促使元素Zr和Ti在M/F界面上快速形成相应的氧化物,并增加了钝化层中氧化层的厚度和稳定性.根据该体系在电解质中的电化学反应,基于点缺陷模型(PDM)建立了简单的动力学模型.利用该模型,结合EIS数据,分析了微合金化提高铜基块体非晶合金耐蚀性能的机理.     

Ti基大块金属玻璃的研究与应用

阐述了Ti基大块金属玻璃(BMG)的成分设计原则及制备方法，并对Ti基非晶合金及其部分晶化复合材料的力学性能及断裂机理进行了评述。结果表明：Ti基大块金属玻璃具有较高的断裂强度、弹性延伸率及一定的塑性延伸率，而经过部分晶化获得的非晶合金基纳米颗粒复合材料，其室温塑性获得很大的改善。在此基础上探讨了该合金目前所存在的问题、研究热点以及其应用前景。     

Misch metal based metallic glasses

In this paper, a glass-forming range of metallic glasses based on Ce-rich misch metal (Mm) was pinpointed in Mm-Al-Co composition map by melt spinning. The thermal analysis indicated that the wide supercooled liquid region (above 60 K) can be found out in a large composition range in Mm-Al-Co system. The investigation of the glass-forming ability (GFA) in this system indicated a glassy composition with a larger supercooled liquid region wouldn’t be the glassy former with higher GFA. The reduced glass transition temperature is a better indicator to explore metallic glasses with high GFA. Furthermore, the mechanical properties of Mm₆₅Al₁₀Co₂₅ bulk glassy samples were evaluated in a compressive measurement. The obvious advantages of the Mm-based BMGs with high GFA, good mechanical properties and low material cost make these BMGs hopeful to be applied in the future.     

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.     

高耐腐蚀Fe-(Cr,Ni)-Mo-P-C-B块体非晶合金

Fe-Mo-P-C-B铁基块体非晶合金具有高强度、高塑性和良好的软磁性,作为结构和功能材料具有较好的应用前景。本研究通过Cr、Ni合金化制备了耐腐蚀Fe-(Cr,Ni)-Mo-P-C-B块体非晶合金,其非晶形成临界直径达5mm。Cr、Ni合金化显著提高了Fe-Mo-P-C-B块体非晶合金在HCl、H2SO4、NaCl溶液中的耐腐蚀性能,使钝化电流密度降低、腐蚀速度降低、电化学反应电阻增大。