Effect of zirconium content on the microstructure and corrosion behavior of Ti-6Al-4V- x Zr alloys

Gao

et al. 2021

Coatings

Plasma alloying technique capable of producing metallic coatings with metallurgical bonding has attracted much attention in dental and orthopedic fields. In this study, the effects of temperature and time of plasma tantalum (Ta) alloying technique on the mechanical, electrochemical, and osteoblastic properties of Ta coatings were systematically investigated. Ta coatings prepared at 800 °C possess better interfacial strengths than those prepared at 750 and 850 °C, and the interfacial strength increases with prolonged alloying time (30–120 min). At 800 °C, however, the increased proportion of the soft Ta deposition layer with alloying time in the whole coating impairs the surface mechanical properties of the entire coating, as convinced by decreased microhardness and wear resistance. Moreover, Ta coatings exhibit better corrosion resistance than the Ti6Al4V substrate in Dulbecco’s modified Eagle medium. The enhanced adhesion and extracellular matrix mineralization level of osteoblasts demonstrate the better cytocompatibility and osteogenic activity of the Ta coating. Ta30 (Ta coating prepared at 800 °C for 30 min) exhibits excellent mechanical, electrochemical, and osteoblastic behaviors and is promising in biomedical applications.

Section: Introductionmentioning

confidence: 99%

Mechanical, Electrochemical, and Osteoblastic Properties of Gradient Tantalum Coatings on Ti6Al4V Prepared by Plasma Alloying Technique

Gao

et al. 2021

Coatings

“…The service life of β Ti alloys is dependent on their corrosion behavior, and it was reported that their metallurgical defects and different service environments (such as those in chemical and marine industries) cause various types of corrosion damages [8,9]. According to literature [10][11][12], the formed passive protective layer can be gradually in the electrolyte due to the concentrated corrosive ions (such as Fand Cl -), and pitting corrosion appears after the oxide layer is destroyed [8,13]. This process can be explained by the preferred adsorption of corrosive ions [9].…”

Section: Introductionmentioning

confidence: 99%

“…It is well known that corrosion resistance and passivation behavior of Ti alloys are relied on the microstructures and relative density of passive layer [13,14]. Some studies [15][16][17] reported that the passive film formed on Ti alloy surface is mainly composed of titanium oxide (TiO 2 ), and also a small amount of suboxides (TiO and Ti 2 O 3 ).…”

Section: Introductionmentioning

confidence: 99%

“…In addition, the microstructure is also a key factor to influence the corrosion performance of β Ti alloys [13]. Some studies showed that the α+β interphase acted as a preferential dissolution locations to trigger the pitting reaction [5,13]. However, there are still a lot of unsolved problems for improving the corrosion performance of Ti alloy.…”

Section: Introductionmentioning

confidence: 99%

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Influence of αs precipitates on electrochemical performance and mechanical degradation of Ti-1300 alloy

Xirong

Journal of Alloys and Compounds

et al. 2019

The influence of α s precipitates on electrochemical behavior and mechanical degradation of Ti-1300 alloy in artificial seawater have been studied. The results show that corrosion resistance and mechanical degradation have been significantly affected by the formation of acicular α s precipitates. The precipitated α s phase with an acicular shape around 40 ~ 60 nm in width are uniformly distributed inside β grain. Many α s precipitates are intersected each other and keep a well-defined Burgers orientation relationship with β matrix, which restricts the growth of other α s phases due to pinning effect. Within the electrolyte, the α s phases can form "microgalvanic cells" with their adjacent intergranular β phases, which dramatically deteriorate its corrosion resistance. The mechanical properties of the alloy are also degraded with the increase of immersion time due to the pitting reaction. The precipitated microstructure exhibits an inferior mechanical degradation behavior, and this is mainly because a lot of corrosion cavities are nucleate d and propagated at the interface between α s precipitates and prior β grains.

“…Ti alloys are applied in many fields due to their many excellent properties such as exceptional strength-to-weight ratio, high performance at elevated temperatures, high hardenability, outstanding corrosion resistance, good biocompatibility and excellent fatigue propagation properties [ 1 , 2 , 3 , 4 , 5 ]. However, their poor tribological properties and high thermal expansion coefficient restrict their application [ 6 , 7 ], especially as structural materials in the extreme space environment.…”

Section: Introductionmentioning

confidence: 99%

Novel Anisotropic Ductility of a High Strength Annealed Ti-20Zr-6.5Al-4V Alloy

Jia

et al. 2018

Materials

Self Cite

In this work, we investigate the mechanical properties of an annealed high strength Ti-20Zr-6.5Al-4V alloy in uniaxial tensile tests in different directions. The results show that the alloy exhibits obvious anisotropic ductility in different directions, while the tensile strength of the alloy remains almost unchanged. This phenomenon is closely related to α laths with similar orientations along the prior-β grain boundaries. These α laths significantly affect the initiation and propagation of cracks when the alloy reaches its yield limit, thereby affecting the ductility of the alloy, such that it exhibits anisotropic ductility.