scholarly journals Influence of the Processing Method on the Properties of Ti-23 at.% Mo Alloy

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 931 ◽  
Author(s):  
Patrycja Sochacka ◽  
Andrzej Miklaszewski ◽  
Kamil Kowalski ◽  
Mieczyslaw Jurczyk
Keyword(s):  
Corrosion Resistance ◽  
Young’S Modulus ◽  
Hot Pressing ◽  
Single Phase ◽  
Young's Modulus ◽  
Synthesis Method ◽  
Indentation Modulus ◽  
Powder Preparation ◽  
Mechanically Alloyed ◽  
Β Phase

In this paper, binary β type Ti-23 at.% Mo alloys were obtained by arc melting as well as by mechanical alloying and powder metallurgical process with cold powder compaction and sintering or, interchangeably, hot pressing. The influence of the synthesis method on the microstructure and properties of bulk alloys were studied. The produced materials were characterized by an X-ray diffraction technique, scanning electron microscopy and chemical composition determination. Young’s modulus was evaluated with nanoindentation testing method based on the Oliver and Pharr approach. The mechanically alloyed Ti-23 at.% Mo powders, after inductively hot-pressed at 800 °C for 5 min, allowed the formation of single Ti(β) phase alloy. In this case, Young’s modulus and Vickers hardness were 127 GPa and 454 HV0.3, respectively. Among the examined materials, the porous (55%) single-phase scaffold showed the lowest indentation modulus (69.5 GPa). Analytical approach performed in this work focuses also on the surface properties. The estimation includes the corrosion resistance analyzed in the potentiodynamic test, and also some wettability properties as a contact angle, and surface free energy values measured in glycerol and diiodomethane testing fluids. Additionally, surface modification of processed material by micro-arc oxidation and electrophoretic deposition on the chosen samples was investigated. Proposed procedures led to the formation of apatite and fluorapatite layers, which influence both the corrosion resistance and surface wetting properties in comparison to unmodified samples. The realized research shows that a single-phase ultrafine-grained Ti-23 at.% Mo alloy for medical implant applications can be synthesized at a temperature lower than the transition point by the application of hot pressing of mechanically alloyed powders. The material processing, that includes starting powder preparation, bulk alloy transformation, and additional surface treatment functionalization, affect final properties by the obtained phase composition and internal structure.

Phase Stability and Mechanical Properties of Ti-Cr-Sn-Zr Alloys Containing a Large Amount of Zr

2016 ◽  
Vol 879 ◽  
pp. 1344-1349 ◽  
Author(s):  
Yonosuke Murayama ◽  
Erdnechuluun Enkhjavkhlan ◽  
Akihiko Chiba
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Deformation Behavior ◽  
Single Phase ◽  
Young's Modulus ◽  
Martensitic Structure ◽  
Β Phase ◽  
Microstructural Transition ◽  
Zr Alloy ◽  
Zr Alloys

The Young’s modulus of Ti-Cr-Sn-Zr alloy varies with the composition of Cr, Sn and Zr, in which the elements act as β stabilizers. Some Ti-Cr-Sn-Zr alloys show very low Young’s modulus under 50GPa. The amount of Zr in alloys with very low Young's modulus increases with the decrease of Cr. We investigated the Young’s modulus and deformation behavior of Ti-xCr-Sn-Zr (x=0~1mass%) alloys containing a large amount of Zr. The quenched microstructure of Ti-Cr-Sn-Zr alloys changes from martensitic structure to β single-phase structure if the amounts of β stabilized elements are increased. The Ti-Cr-Sn-Zr alloys with compositions close to the transitional composition of microstructure from martensite to β phase show minimum Young’s modulus. The clear microstructural transition disappears and the minimum Young’s modulus increases if the amount of Cr becomes too small. In Ti-Cr-Sn-Zr alloys containing a large amount of Zr, Young’s modulus depends on β phase that is intermingled with martensite.

scholarly journals First principles computation of composition dependent elastic constants of omega in titanium alloys: implications on mechanical behavior

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Salloom ◽  
S. A. Mantri ◽  
R. Banerjee ◽  
S. G. Srinivasan
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
First Principles ◽  
Young's Modulus ◽  
Group Vi ◽  
Group V ◽  
Β Phase ◽  
Ti Alloys ◽  
Ω Phase ◽  
Stabilizer Concentration

AbstractFor decades the poor mechanical properties of Ti alloys were attributed to the intrinsic brittleness of the hexagonal ω-phase that has fewer than 5-independent slip systems. We contradict this conventional wisdom by coupling first-principles and cluster expansion calculations with experiments. We show that the elastic properties of the ω-phase can be systematically varied as a function of its composition to enhance both the ductility and strength of the Ti-alloy. Studies with five prototypical β-stabilizer solutes (Nb, Ta, V, Mo, and W) show that increasing β-stabilizer concentration destabilizes the ω-phase, in agreement with experiments. The Young’s modulus of ω-phase also decreased at larger concentration of β-stabilizers. Within the region of ω-phase stability, addition of Nb, Ta, and V (Group-V elements) decreased Young’s modulus more steeply compared to Mo and W (Group-VI elements) additions. The higher values of Young’s modulus of Ti–W and Ti–Mo binaries is related to the stronger stabilization of ω-phase due to the higher number of valence electrons. Density of states (DOS) calculations also revealed a stronger covalent bonding in the ω-phase compared to a metallic bonding in β-phase, and indicate that alloying is a promising route to enhance the ω-phase’s ductility. Overall, the mechanical properties of ω-phase predicted by our calculations agree well with the available experiments. Importantly, our study reveals that ω precipitates are not intrinsically embrittling and detrimental, and that we can create Ti-alloys with both good ductility and strength by tailoring ω precipitates' composition instead of completely eliminating them.

Fabrication of Be-Ta Ti Alloys without Pre-Alloyed Powders via SLM

2021 ◽  
Vol 1016 ◽  
pp. 1797-1801
Author(s):  
Mitsuharu Todai ◽  
Takeshi Nagase ◽  
Takayoshi Nakano
Keyword(s):  
Young’S Modulus ◽  
Melting Temperature ◽  
Crystallographic Texture ◽  
Crystal Orientation ◽  
Single Phase ◽  
Young's Modulus ◽  
Laser Melting ◽  
Ti Alloys

In this study, we sucsess the fabrication of dense compornent of Ti-20at.%X (X = Cr and Nb) alloys by Selected laser melting (SLM) pwocess, from a mixture of poweder element powders. The volume rasio of pore and non-molten particles is dependent of the enegy density. The difficulty of fabrication of Ti-X alloy comporment is dependent of melting temperature of X element. Thus, Ti-20at.%Cr alloys, which has the lowest melting temperature of X is easier to monufacture of dense comporment. The Ti-20at.%Cr alloys and Ti-20at.%Nb comprise β-Ti single-phase components without any non-molten particles and macroscopic defects. In addtion, the {001}〈100〉 crystallographic texture of these Ti-Cr and Ti-Nb alloys can be controlled effectively by optimizing the SLM parameters. This means that the SLM is key techmelogy of controlling of Young’s modulus and shape at the same time because Young's modulus of be-ta phase in Ti alloys is strongly related to the crystal orientation.

Mechanical Properties of Ti-Cr-Sn-Zr Alloys

2010 ◽  
Vol 638-642 ◽  
pp. 635-640 ◽  
Author(s):  
Yonosuke Murayama ◽  
Shuichi Sasaki ◽  
Hisamichi Kimura ◽  
Akihiko Chiba
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Biomedical Application ◽  
Young's Modulus ◽  
Mechanical Twinning ◽  
Β Phase ◽  
Low Modulus ◽  
Deformation Modes ◽  
Zr Alloy ◽  
Zr Alloys

Low modulus β Ti alloys are attractive for biomedical application. This work examines the mechanical properties of Ti-Cr-Sn-Zr system alloys, especially the effect of the varying alloy composition on the microstructure, the Young’s modulus and the deformation mechanism.The Young’s modulus of the alloy varies with the composition, which variation is caused mainly from the competition between the meta-stable β phase and ω phase.The deformation modes of the Ti-Cr-Sn-Zr alloy, which are the mechanical twinning, the deformation by slip and the deformation-induced transformation, also change depending on the composition of the alloy. The minimum of the Young’s modulusof the Ti-Cr-Sn-Zr alloy in this experiment was shown in the composition where the microstructure of the alloy changes from the martensitic structure to the meta-stable β structure.

Mechanical Properties of Transparent Polycrystalline Silicon Nitride

2006 ◽  
Vol 317-318 ◽  
pp. 305-308 ◽  
Author(s):  
Rak Joo Sung ◽  
Takafumi Kusunose ◽  
Tadachika Nakayama ◽  
Yoon Ho Kim ◽  
Tohru Sekino ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Silicon Nitride ◽  
Young’S Modulus ◽  
Fracture Strength ◽  
Polycrystalline Silicon ◽  
Volume Fraction ◽  
Young's Modulus ◽  
Β Phase ◽  
Α Phase

A novel transparent polycrystalline silicon nitride was fabricated by hot-press sintering with MgO and AlN as additives. The mixed powder with 3 wt.% MgO and 9 wt.% AlN was sintered at 1900oC for 1 hour under 30 MPa pressure in a nitrogen gas atmosphere. Transparent polycrystalline silicon nitride was successfully fabricated. The mechanical properties such as density, hardness, young’s modulus, fracture strength and fracture toughness were evaluated. The effect of α/β phase on the mechanical properties of transparent polycrystalline silicon nitride was investigated. The properties were changed depending on the amount of α/β phase. The hardness and Young's modulus increased with increasing the volume fraction of α-phase fraction as a reflection of the higher hardness of α-phase Si3N4. The fracture toughness and fracture strength decreased with decreasing the volume fraction of β-phase Si3N4.

scholarly journals Improving the Mechanical Properties of a β-type Ti-Nb-Zr-Fe-O Alloy

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1491 ◽  
Author(s):  
Vasile Danut Cojocaru ◽  
Anna Nocivin ◽  
Corneliu Trisca-Rusu ◽  
Alexandru Dan ◽  
Raluca Irimescu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Solution Treatment ◽  
Tensile Tests ◽  
Research Directions ◽  
Biomedical Implant ◽  
Advantages And Disadvantages ◽  
Β Phase

The influence of complex thermo-mechanical processing (TMP) on the mechanical properties of a Ti-Nb-Zr-Fe-O bio-alloy was investigated in this study. The proposed TMP program involves a schema featuring a series of severe plastic deformation (SPD) and solution treatment (STs). The purpose of this study was to find the proper parameter combination for the applied TMP and thus enhance the mechanical strength and diminish the Young’s modulus. The proposed chemical composition of the studied β-type Ti-alloy was conceived from already-appreciated Ti-Nb-Ta-Zr alloys with high β-stability by replacing the expensive Ta with more accessible Fe and O. These chemical additions are expected to better enhance β-stability and thus avoid the generation of ω, α’, and α” during complex TMP, as well as allow for the processing of a single bcc β-phase with significant grain diminution, increased mechanical strength, and a low elasticity value/Young’s modulus. The proposed TMP program considers two research directions of TMP experiments. For comparisons using structural and mechanical perspectives, the two categories of the experimental samples were analyzed using SEM microscopy and a series of tensile tests. The comparison also included some already published results for similar alloys. The analysis revealed the advantages and disadvantages for all compared categories, with the conclusions highlighting that the studied alloys are suitable for expanding the database of possible β-Ti bio-alloys that could be used depending on the specific requirements of different biomedical implant applications.

Fabrication of Al2O3/BN Nanocomposites by Chemical Processing and Their Mechanical Properties

2005 ◽  
Vol 20 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Takafumi Kusunose ◽  
Yoon-Ho Kim ◽  
Tohru Sekino ◽  
Takuya Matsumoto ◽  
Norihito Tanaka ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Boundaries ◽  
Young’S Modulus ◽  
Hot Pressing ◽  
Young's Modulus ◽  
High Strength ◽  
Synthesis Process ◽  
Chemical Processing ◽  
Chemical Route ◽  
Nanocomposite Structures

Al2O3/BN nanocomposites were fabricated through a novel chemical route involving hot-pressing of α–Al2O3 powders covered partly with turbostratic BN (t-BN). The nano-sized hexagonal BN (h-BN) particles were found to be homogeneously dispersed within the Al2O3 grains as well as at grain boundaries, which is indicative of nanocomposite structures. Thus, the present nanocomposites exhibited the unique properties of high strength and low Young’s modulus associated with nanocomposites. This paper discusses in detail the synthesis process and microstructural features of these materials.

Mechanocyclic and Time Stability of the Loading-Unloading Diagram Parameters of Nanostructured Ti-Nb-Ta and Ti-Nb-Zr SMA

2013 ◽  
Vol 738-739 ◽  
pp. 481-485 ◽  
Author(s):  
Sergey Prokoshkin ◽  
Vladimir Brailovski ◽  
Mikhail Petrzhik ◽  
Mikhail R. Filonov ◽  
Vadim Sheremetyev
Keyword(s):  
Young’S Modulus ◽  
Tensile Strain ◽  
Room Temperature ◽  
Young's Modulus ◽  
Cold Drawing ◽  
Half Cycle ◽  
Time Stability ◽  
Mechanical Hysteresis ◽  
Β Phase ◽  
Superelastic Behavior

The Ti-21.8Nb-6Zr and Ti-19.7Nb-5.8Ta (at.%) shape memory alloys are thermomechanically treated by cold drawing and post-deformation annealing at 550-600°C forming a nanosubgrained structure in the β-phase. Cyclic mechanical testing using a “loading-unloading” mode with 2% tensile strain in each half-cycle reveals the non-perfect superelastic behavior of both alloys during the very first cycles of testing, which becomes perfect during further mechanocycling. The Young’s modulus of thermomechanically-treated alloys is low (about 45 GPa), and it decreases during mechanocycling (n=10 cycles) down to 25-35 GPa, approaching the Young’s modulus of cortical bone tissues. The Young’s modulus obtained in the 10th cycle is stable or changes only slightly during a further 40-day pause at room temperature and then during repeated mechanocycling. The residual strain per cycle, the transformation yield stress and the mechanical hysteresis decrease during mechanocycling. Subsequent to a 40-day pause at room temperature, they restore their initial values. Repeated mechanocycling is accompanied by a repeated decrease of these parameters.

Microstructure Formation Mechanism of (Al2O3+TiB2+Al3Ti)/Al Composites Fabricated by Reactive Hot Pressing

2007 ◽  
Vol 353-358 ◽  
pp. 1439-1442 ◽  
Author(s):  
Gui Song Wang ◽  
Lin Geng
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Formation Mechanism ◽  
Hot Pressing ◽  
Young's Modulus ◽  
Microstructure Formation ◽  
Sem And Tem ◽  
Reactive Hot Pressing ◽  
Tib2 Particles

The two (Al2O3+TiB2+Al3Ti)/Al composites were fabricated from Al-B2O3-TiO2 and Al-B-TiO2 raw powders by reactive hot pressing, respectively. The microstructure of in situ two composites was analyzed by OM, SEM and TEM. The results showed that coarse Al3Ti blocks with several tens of micrometers size were formed during hot pressing. The equiaxed Al2O3 particulates and hexagonal TiB2 particulates with finer sizes were formed in the composites simultaneously. The microstructure formation mechanism of (Al2O3+TiB2+Al3Ti)/Al composites were discussed. The results showed that Al2O3 reinforcements were formed on the surface of TiO2 or B2O3 powder and TiB2 particles were formed on B or B2O3 powders. The formation of coarse Al3Ti block is result from continuous diffusion of Ti in liquid Al during reactive hot pressing. In addition, there are fine Al3Ti precipitates exist in the composite fabricated from Al-B-TiO2 powders. This contributes to the improved mechanical properties in terms of yield and ultimate stresses and Young’s modulus of the composite.

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