A review on alloy design, biological response, and strengthening of β-titanium alloys as biomaterials

https://ro.ecu.edu.au/cgi/viewcontent.cgi?article=6321&context=ecuworkspost2013

Improved deformation behavior in Ti-Zr-Fe-Mn alloys comprising the C14 type Laves and β phases

https://ro.ecu.edu.au/cgi/viewcontent.cgi?article=6986&context=ecuworkspost2013

Deformation and strength characteristics of Laves phases in titanium alloys

An impressive strengthening ability of Laves phases is favorable to develop titanium alloys with an improved trade-off between strength and plasticity. Therefore, the Ti-xZr-7Fe-ySn (x = 25, 30, 35 wt% and y = 1, 2 wt%) alloys were first designed in such a manner that a Laves phase would precipitate in these alloys and then the investigated alloys were produced by cold crucible levitation melting. A hexagonal close-packed C14 type Laves phase along with a dominant fraction of body-centered cubic β phase are formed in all the as-cast Ti-xZr-7Fe-ySn alloys except in Ti-25Zr-7Fe-2Sn. The volume fraction of the Laves-C14 phase is found to be sensitive to the quantities of Zr and Sn. Amongst all the investigated alloys, Ti-35Zr-7Fe-2Sn shows a better dislocation-pinning ability in terms of dislocation density (3.96 × 1015 m−2), yield strength (1359 MPa) and hardness (437 HV), whereas Ti-25Zr-7Fe-1Sn shows a better deformation ability in terms of compressive strain at failure (36.2%) and plastic strain (31.9%). Crack propagation, regions of dimples and deformation bands are examined in the fracture analyses. Moreover, in this work, Ti-25Zr-7Fe-1Sn exhibits the best strength and plasticity trade-off in terms of a product of ultimate strength and compressive strain at failure (77.4 GPa %).

Improved trade-off between strength and plasticity in titanium based metastable beta type Ti-Zr-Fe-Sn alloys

Since the Material Genome Initiative (MGI) was proposed, high-throughput based technology has been widely employed in various fields of materials science. As a theoretical guide, material informatics has been introduced based on machine learning and data mining and high-throughput computation has been employed for large scale search, narrowing down the scope of the experiment trials. High-throughput materials experiments including synthesis, processing, and characterization technologies have become valuable research tools to pin down the prediction experimentally, enabling the discovery-to-deployment of advances materials more efficiently at a fraction of cost. This review aims to summarize the recent advances of high-throughput materials experiments and introduce briefly the development of materials design based on material genome concept. By selecting representative and classic works in the past years, various high-throughput preparation methods are introduced for different types of material gradient libraries, including metallic, inorganic materials, and polymers. Furthermore, high-throughput characterization approaches are comprehensively discussed, including both their advantages and limitations. Specifically, we focus on high-throughput mass spectrometry to analyze its current status and challenges in the application of catalysts screening.

High-throughput experiments facilitate materials innovation: A review

CALPHAD-type modeling was used to describe the single-crystal elastic constants of the bcc solution phase in the ternary Ti-Nb-Zr system. The parameters in the model were evaluated based on the available experimental data and first-principle calculations. The composition-elastic properties of the full compositions were predicted and the results were in good agreement with the experimental data. It is found that the β phase can be divided into two regions which are separated by a critical dynamical stability composition line. The corresponding valence electron number per atom and the polycrystalline Young׳s modulus of the critical compositions are 4.04-4.17 and 30-40GPa respectively. Orientation dependencies of single-crystal Young׳s modulus show strong elastic anisotropy on the Ti-rich side. Alloys compositions with a Young׳s modulus along the direction matching that of bone were found. The current results present an effective strategy for designing low modulus biomedical alloys using computational modeling.

Study of low-modulus biomedical β Ti-Nb-Zr alloys based on single-crystal elastic constants modeling.

Experimental investigation of Ti-Nb-Co ternary system at 1000 °C

Phase relations in the Al-Co-Y ternary system at 1173 K have been established by means of scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and X-ray diffraction (XRD) techniques. Isothermal section at 1173 K of this system was constructed, which consists of 27 three-phase regions and 50 two-phase regions (27wider+23line). The ternary compound τ 5 -AlCo 2 Y 2 has been confirmed to exist and the crystal structure has been preliminarily analyzed with pattern indexing method as well. The intermetallic phase Co 2 Y, Co 3 Y, Co 7 Y 2 , Co 5 Y, Co 17 Y 2, Al 2 Y, τ 4 -AlCoY and τ 5 -AlCo 2 Y 2 were expressed as the formula of Al x Co 2−x Y, Al x Co 3−x Y, Al x Co 7−x Y 2 , Al x Co 5−x Y, Al x Co 17−x Y 2 , Al 2−x Co x Y, Al 1+x Co 1−x Y and Al 1−x Co 2+x Y 2 , respectively.

Experimental investigation of phase relations in Al-Co-Y ternary system

A combinatorial approach has been applied to build the database of composition dependent microstructure and hardness of the Ti5553–Fe system. The relationship between the composition and microstructure as well as the hardness was obtained. (Ti5553)96-Fe4 was found to have almost the same hardness as that of Ti5553, but a relatively coarser intragranular α phase. High-angle annular dark field imaging revealed that Fe mainly concentrated in the β phase, which strengthened the β phase through solution strengthening. This means that (Ti5553)96-Fe4 may have the same strength as that of Ti5553 but higher fracture toughness. The formation of FeCr compound consumed the β stabilizer elements Fe and Cr, which led to unusual increasing of the nucleation rate and the volume fraction of α phase in (Ti5553)88-Fe12.

Investigation of the influence of Fe on the microstructure and properties of Ti5553 near-β titanium alloy with combinatorial approach

The Al-rich region of the ternary Al–Cu–Er system is investigated using the method of X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy. Phase equilibria in the Al-rich region of the Al–Cu–Er system at 673 K have been obtained, and the microstructures of as-cast alloys in the Al-rich region are also investigated. One ternary phase 1-Al8Cu4Er with a composition of 59.4–60.4 at.% Al, 32.2–33.8 at.% Cu, and 6.4–7.7 at.% Er is observed in both as-cast and annealed alloys. At 673 K, the binary Al3Er phase dissolves about 3.51 at.% Cu. The calculated solidification paths (based on the CALPHAD method) of as-cast alloys are in agreement with the experimental results. © 2010 Elsevier B.V. All rights reserved.

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Yun Jiang

Papers

Study of low-modulus biomedical β Ti-Nb-Zr alloys based on single-crystal elastic constants modeling.

Experimental investigation of Ti-Nb-Co ternary system at 1000 °C

Experimental investigation of phase relations in Al-Co-Y ternary system

Investigation of the influence of Fe on the microstructure and properties of Ti5553 near-β titanium alloy with combinatorial approach

Phase relationships in the Al-rich region of the Al-Y-Zr system