Deformation induced nanoscale twinning improves strength and ductility in additively manufactured titanium alloys

CP-Ti, Ti 6A l 4V (ELI), and Ti 6Al 7Nb are often used for manufacturing osteosynthesis products or implants. However, researches have revealed that Al and V can have detrimental effects on the human body. Therefore, several Al- and V-free near-α and (α+β) titanium alloys have been developed on the basis of CP-Ti Grade 4+ (Ti 0.4O 0.5Fe 0.08C). They should possess similar or better mechanical properties than Ti 6Al 4V (ELI) combined with an improved biocompatibility and good corrosion resistance. O, C, Fe, Au, Si, Nb, or Mo have been used as alloying elements, which are either already present in the human body or are biocompatible. Several of the studied alloys show a strength and ductility fulfilling the requirements of Ti 6Al 4V ELI as specified in ASTM F136. For instance, Ti 0.44O 0.5Fe 0.08C 2.0Mo exhibits a YTS of approx. 1005 MPa, an UTS of approx. 1015 MPa, and an elongation at rupture of at least 17%. Therefore, one or more of the studied alloys are promising candidates for replacing Ti 6Al 4V ELI in osteosynthesis and implant applications.

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Microstructure-Based Estimation of Strength and Ductility Distributions for $$\alpha +\beta $$ Titanium Alloys

Metallurgical and Materials Transactions A ◽

10.1007/s11661-021-06233-5 ◽

2021 ◽

Author(s):

McLean P. Echlin ◽

Matthew Kasemer ◽

Kamalika Chatterjee ◽

Donald Boyce ◽

Jean Charles Stinville ◽

...

Keyword(s):

Titanium Alloys ◽

Beta Titanium ◽

Alpha Beta ◽

Strength And Ductility ◽

Beta Titanium Alloys

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Effect of strain rate on the strength and ductility of titanium alloys

Strength of Materials ◽

10.1007/bf01118035 ◽

1980 ◽

Vol 12 (5) ◽

pp. 584-586 ◽

Cited By ~ 3

Author(s):

G. V. Stepanov ◽

B. A. Kovalev

Keyword(s):

Strain Rate ◽

Titanium Alloys ◽

Strength And Ductility

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Enhancement of Mechanical Biocompatibility of Titanium Alloys by Deformation-Induced Transformation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.879.125 ◽

2016 ◽

Vol 879 ◽

pp. 125-130

Author(s):

Mitsuo Niinomi

Keyword(s):

Fracture Toughness ◽

Titanium Alloy ◽

Phase Transformation ◽

Titanium Alloys ◽

Biomedical Applications ◽

Hard Tissue ◽

Β Phase ◽

Ω Phase ◽

Increased Strength ◽

Strength And Ductility

Metastable β-type titanium alloys are highly suitable for use as structural biomaterials applied to hard tissue, i.e., as cortical bone (hereafter, bone) replacing implants. However, their mechanical biocompatibitities, such as the Young’s modulus, strength and ductility balance, fatigue strength, resistance against fatigue crack propagation and fracture toughness, require improvenent for increased compatibility with bone. Through deformation, the metastable β-phase in a metastable β-type titanium alloy is transformed into various phases, such as α’ martensite, α” martensite, and ω-phases with exact phase depending by metastable β-phase stability. In addition, twinning is also induced by deformation. Deformation twinning effectively enhances the work hardening in the metastable β-type titanium alloy, leading to increased strength and ductility. This improvement is accompanied by with other deformation-induced transformations including the appearance of deformation-induced martensite and ω-phase transformation. The enhancement of the mechanical biocompatibility of various materials using the abovementioned deformation-induced transformation is described in this paper, for both newly developed metastable β-type Ti-Mo and Ti-Cr alloys for biomedical applications.

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Superplastic Grade Titanium Alloy: Comparative Evaluation of Mechanical Properties, Microstructure, and Fracture Behavior

Journal of Materials ◽

10.1155/2016/2309232 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 5

Author(s):

K. V. Sudhakar ◽

Ethan Wood

Keyword(s):

Heat Treatment ◽

Titanium Alloys ◽

Comparative Evaluation ◽

Fracture Behavior ◽

Test System ◽

The Other ◽

Static Fracture ◽

Strength And Ductility ◽

Biomedical Fields ◽

Made In

In this investigation, static fracture, microstructure, and the mechanical behavior of SP-700 alloy (a superplastic grade) were evaluated and compared with two other titanium alloys. The comparisons were made in terms of suitably designed heat treatment cycles. The heat treatment cycles included annealing and a combination of solutionizing and aging treatments for all three alloys. Tensile properties were determined using MTS Landmark Servohydraulic Test System. Tensile tested samples’ fracture surfaces were investigated with LEO-VP SEM instrument. Ti-15-3-3-3 alloy exhibited relatively a higher combination of strength and ductility in comparison to the other two alloys. All three types of titanium alloys demonstrated a very good level of tensile strength and ductility suitable for applications in military and biomedical fields.

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Electron Beam Cold Hearth Melted Titanium Alloys and the Possibility of Their Use as Anti-Ballistic Materials

MATEC Web of Conferences ◽

10.1051/matecconf/202032111036 ◽

2020 ◽

Vol 321 ◽

pp. 11036

Author(s):

P.E. Markovsky ◽

V.I. Bondarchuk ◽

S.V. Akhonin ◽

A.V. Berezos

Keyword(s):

Titanium Alloys ◽

Plate Thickness ◽

Two Phase ◽

Ballistic Resistance ◽

Commercial Titanium ◽

Final Aging ◽

Gradient Microstructure ◽

Rapid Heat Treatment ◽

Strength And Ductility ◽

Hardened Surface

Three commercial titanium alloys: two-phase α+β Ti-6Al-4V (low alloyed), and T110 (Ti-5.5Al-1.5V-1.5Mo-4Nb-0.5Fe, higher-alloyed), and β-metastable Ti-1.5Al-6.8Mo-4.5Fe were melted using EBCHM approach in the form of 100 mm in diameter ingots with the weight of about 20 kg each. After 3D hot pressing at single β-field temperatures ingots were rolled at temperatures below β-transus onto plates with thickness varying from 3 mm to 25 mm. Different heat treatments, including annealing at α+β or β-field temperatures, and special strengthening Surface Rapid Heat Treatment (SRHT) which after final aging provided special gradient microstructure with a hardened surface layer over ductile basic core, were employed. Mechanical properties were studied with tensile and 3-point flexure tests. It was established that the best combination of tensile strength and ductility in all alloys studied was obtained after SRHT, whereas at 3-point flexure better characteristics were obtained for the materials annealed at temperatures of (α+β)-field. At the same time, ballistic tests made at a certified laboratory with different kinds of ammunition showed essential superiority of plates having upper layers strengthened with SRHT. The effect of microstructure of the alloys, plate thickness and type of used ammunition on ballistic resistance is discussed.

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Strength and ductility of titanium alloys at low temperatures

Metal Science and Heat Treatment ◽

10.1007/bf00668852 ◽

1970 ◽

Vol 12 (6) ◽

pp. 464-466

Author(s):

V. A. Moskalenko ◽

V. N. Puptsova ◽

R. A. Ul'yanov

Keyword(s):

Titanium Alloys ◽

Low Temperatures ◽

Strength And Ductility

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Effect of graphene nanoplatelets (GNPs) addition on strength and ductility of magnesium-titanium alloys

Journal of Magnesium and Alloys ◽

10.1016/j.jma.2013.09.004 ◽

2013 ◽

Vol 1 (3) ◽

pp. 242-248 ◽

Cited By ~ 91

Author(s):

Muhammad Rashad ◽

Fusheng Pan ◽

Aitao Tang ◽

Yun Lu ◽

Muhammad Asif ◽

...

Keyword(s):

Titanium Alloys ◽

Graphene Nanoplatelets ◽

Strength And Ductility

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Direct Observation of the Diffusionless β → β + ω Transformation in Titanium Alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100064669 ◽

1971 ◽

Vol 29 ◽

pp. 122-123

Author(s):

N. E. Paton ◽

D. de Fontaine ◽

J. C. Williams

Keyword(s):

Electron Microscope ◽

Titanium Alloys ◽

Direct Observation ◽

Dark Field ◽

X Ray Diffraction ◽

Resistivity Measurements ◽

Selected Area Electron Diffraction ◽

Ti Alloys ◽

Thin Foils ◽

Field Device

The electron microscope has been used to study the diffusionless β → β + ω transformation occurring in certain titanium alloys at low temperatures. Evidence for such a transformation was obtained by Cometto et al by means of x-ray diffraction and resistivity measurements on a Ti-Nb alloy. The present work shows that this type of transformation can occur in several Ti alloys of suitable composition, and some of the details of the transformation are elucidated by means of direct observation in the electron microscope.Thin foils were examined in a Philips EM-300 electron microscope equipped with a uniaxial tilt, liquid nitrogen cooled, cold stage and a high resolution dark field device. Selected area electron diffraction was used to identify the phases present and the ω-phase was imaged in dark field by using a (101)ω reflection. Alloys were water quenched from 950°C, thinned, and mounted between copper grids to minimize temperature gradients in the foil.

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