Influence of Fe Content of Ti-Mn-Fe Alloys on Phase Constitution and Heat Treatment Behavior

2012 ◽  
Vol 706-709 ◽  
pp. 1893-1898 ◽  
Author(s):  
Masahiko Ikeda ◽  
Masato Ueda ◽  
Takahiro Kinoshita ◽  
Michiharu Ogawa ◽  
Mitsuo Niinomi
Keyword(s):  
Vickers Hardness ◽  
Beta Phase ◽  
Optical Microscope ◽  
Alpha Phase ◽  
Omega Phase ◽  
X Ray Diffraction ◽  
Fe Content ◽  
Valence Electrons ◽  
Fe Alloys ◽  
Stabilizing Element

If Mn could be partly substituted by Fe, Ti-Mn-Fe alloys would be less costly than Ti-Mn alloys. Furthermore, the use of iron as a beta-stabilizing element is more suitable than the use of manganese from a situation of an element strategy. In this study, 4.26 was admitted as the average ratio of valence electrons to atoms, e/a. The compositions of Mn and Fe were chosen under 4.26 as e/a. We investigated the influence Fe in selected Ti-Mn-Fe alloys by performing electrical resistivity, Vickers hardness, and X-ray diffraction measurements. In solution-treated and water-quenched 10Mn alloy, the beta and athermal omega phases were identified, while only the beta phase was identified in 8.7Mn-1Fe, 6.1Mn-3Fe, and 3.5Mn-5Fe alloys. In all alloys, equiaxial beta grains were observed by optical microscope. The resistivities at room and liquid-nitrogen temperatures and the Vickers hardness were relatively invariant across all Ti-Mn-Fe alloys, except for the Vickers hardness of the 5Fe alloy. During aging at 773 K, an isothermal omega phase precipitated in only the 3.5Mn-5Fe alloy, whereas only the alpha phase precipitated in the others.

Development and Research of Low-Cost Titanium Alloys, Especially Case of Japan

2016 ◽  
Vol 879 ◽  
pp. 119-124 ◽  
Author(s):  
Masahiko Ikeda ◽  
Masato Ueda
Keyword(s):  
Heat Treatment ◽  
Vickers Hardness ◽  
Low Cost ◽  
Beta Phase ◽  
Omega Phase ◽  
X Ray Diffraction ◽  
Practical Applications ◽  
Al Content ◽  
Ti Alloys ◽  
Fe Alloys

Titanium (Ti) exhibits many attractive properties that enable practical applications. It is also considered to be a ubiquitous element, since it has the ninth highest Clarke number among all the elements. However, the principal beta-stabilizing elements for Ti, molybdenum and vanadium, can be very expensive, and so many Ti alloys are also costly. For this reason, less expensive alloying elements would be preferable. Iron (Fe) and manganese (Mn) are beta stabilizers for Ti alloys that are readily available, since they have the fourth and eleventh highest Clarke numbers, respectively. Furthermore, since Fe has a large diffusion coefficient in the beta phase of Ti, precipitation of the omega phase occurs more quickly when Fe is added. The behaviors of Ti-Mn and Mn-Fe alloys during heat treatment have been investigated and it has been found that, in some alloys, the isothermal omega phase is precipitated. Because this phase can lead to brittleness of the alloy, it is very important to suppress its precipitation. Since it is well known that aluminum (Al) suppresses isothermal omega precipitation, the present work investigated the effects of Al content on the phase constitution and heat treatment behavior of Ti-8.5 mass%Mn-1 mass%Fe-0, 1.5, 3.0 and 4.5 mass%Al alloys using electrical resistivity, Vickers hardness, and X-ray diffraction measurements. In the case of each of these alloys, whether solution-treated or water-quenched, only the beta phase was identified. The resistivities at room and liquid nitrogen temperatures were found to increase monotonically with Al content, while the Vickers hardness decreased up to 3 mass% Al and then remained constant. The addition of Al was found to suppress omega precipitation.

Effect of Al Addition on Phase Constitution and Heat Treatment Behavior in Ti-8.5mass%Mn-1mass%Fe-Al Alloys

2014 ◽  
Vol 783-786 ◽  
pp. 562-567 ◽  
Author(s):  
Masahiko Ikeda ◽  
Masato Ueda ◽  
Yoshinori Sumi ◽  
Mitsuo Niinomi
Keyword(s):  
Heat Treatment ◽  
Vickers Hardness ◽  
Beta Phase ◽  
Al Alloys ◽  
Omega Phase ◽  
X Ray Diffraction ◽  
Phase Constitution ◽  
Al Content ◽  
Fe Alloys ◽  
Iron And Manganese

Titanium is considered to be a ubiquitous element since it has the 9th-highest Clarke number of all elements. Iron and manganese can also be used as beta stabilizers for Ti alloys, and can be considered to be ubiquitous because of their 4th- and 11th-highest Clarke numbers, respectively. However, investigations into the behavior of Ti-Mn-Fe alloys during heat treatment have shown that in some alloys, the isothermal omega phase is precipitated. Because this phase can lead to brittleness, it is very important to prevent it from forming. It is well known that aluminum can suppress the precipitation of the isothermal omega phase. Thus, in the present study, we investigated the effect of Al content on the phase constitution and heat-treatment behavior of Ti-8.5mass%Mn-1mass%Fe-0 to 4.5mass%Al alloys using electrical resistivity, Vickers hardness, and X-ray diffraction measurements. In all solution-treated and quenched alloys, only the beta phase was identified, thus confirming the suppression of omega-phase precipitation. The resistivity was found to increase monotonically with Al content, while the Vickers hardness decreased up to 3 mass% Al and then remained constant.

scholarly journals Structural characterization of liquid phase sintered silicon carbide by high-resolution X-ray diffractometry

Cerâmica ◽  
2005 ◽  
Vol 51 (318) ◽  
pp. 168-172 ◽  
Author(s):  
C. A. Kelly ◽  
P. A. Suzuki ◽  
S. Ribeiro ◽  
S. Kycia
Keyword(s):  
Silicon Carbide ◽  
High Resolution ◽  
Mixed Oxide ◽  
Beta Phase ◽  
Alpha Phase ◽  
X Ray Diffraction ◽  
Solid Solution Formation ◽  
X Ray ◽  
Synchrotron Light

Silicon carbide (SiC) was sintered using two different additives: AlN-Y2O3 or AlN-CRE2O3. CRE2O3 is a mixed oxide formed by Y2O3 and rare-earth oxides. The crystalline structures of the phases were analyzed by high-resolution X-ray diffraction using synchrotron light source. The results of the Rietveld refinement of the mixed oxide show a solid solution formation. In both silicon carbide samples prepared using AlN-Y2O3 or AlN-CRE2O3 3C (beta-phase) and 6H (alpha-phase) polytypes were found. The structural and microstructural results for both samples were similar. This is an indication of the viability of the use of CRE2O3 in substitution for Y2O3 as additive to obtain dense materials.

Microstructure and Mechanical Properties of Cu-Fe Alloys via Powder Metallurgy

2021 ◽  
Vol 1016 ◽  
pp. 1727-1732
Author(s):  
Chen Zeng Zhang ◽  
Cun Guang Chen ◽  
Tian Xing Lu ◽  
Pei Li ◽  
Fang Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Functional Materials ◽  
Shielding Effect ◽  
X Ray Diffraction ◽  
Microstructure Observation ◽  
Fe Content ◽  
Fe Alloys ◽  
Similar Good

Copper Ferro Alloys (CFAs) have an excellent shielding effect in the electromagnetic field, as well as the similar good conductivity and ductility with copper, and strong magnetism and toughness as analogous to iron. Consequently, it is considered to be novel structural and functional materials with huge development potential and wide application foreground. The influence of the content, size and distribution of Fe phase in the Cu matrix on the electromagnetic shielding property of CFAs is crucial. In the present study, CFAs with various Fe content were fabricated via powder metallurgy (P/M) combining with deformation processing. The microstructure, electrical conductivity, magnetic and mechanical properties of CFAs were investigated by optical microscopy (OM), scanning electron microscopy (SEM), X-Ray diffraction (XRD), and tensile test. The results indicated that P/M CFAs with the homogenous and fine in-situ Fe particles showed better comprehensive performance compared to those prepared by conventional casting. Based on the microstructure observation, mechanical properties were discussed.

Influence of Substitution of Fe by Mo on Heat Treatment Behavior in Ti-Mo-Fe Alloys

2021 ◽  
Vol 1016 ◽  
pp. 162-169
Author(s):  
Kyosuke Mizuta ◽  
Shotaro Miyake ◽  
Masahiko Ikeda ◽  
Masato Ueda
Keyword(s):  
Heat Treatment ◽  
Electrical Resistivity ◽  
Diffusion Coefficient ◽  
Vickers Hardness ◽  
Partial Substitution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Ti Alloys ◽  
Fe Alloys

In order to reduce the cost of β-type Ti alloys, the use of Fe as an alloying element has been studied. However, Fe is known to have a very high diffusion coefficient in β-Ti of about 2.6×10-12 m2/s at 1200 K, and its behavior during heat treatment is expected to be difficult to control. By contrast, Mo, which is also a β-stabilizing element, has a diffusion coefficient of only about 2.5×10-14 m2/s at 1200 K, i.e., roughly 100 times smaller than that of Fe1), 2). In this study, the effect of the partial substitution of Fe with Mo on the aging behavior of β-Ti alloys was investigated using X-ray diffraction, electric resistivity, and Vickers hardness measurements. Ti-Mo-Fe alloys were solution-treated by holding at 1173 K for 3.6 ks and then quenching in ice water. In the X-ray diffraction patterns for the resulting samples, only peaks associated with the β phase were identified. It was found that the electrical resistivity and Vickers hardness decreased with increasing Mo content. As the Mo-to-Fe ratio increased, the decrease in electrical resistivity and the increase in Vickers hardness occurred later during the isothermal aging process. This was due to a delay in isothermal ω-phase precipitation.

The influence of prior cold deformation on precipitation of alpha phase and variation of hardness in Ti-10Mo-8V-1Fe-3.5Al during aging treatment

2009 ◽  
Vol 24 (2) ◽  
pp. 452-458 ◽  
Author(s):  
Z.Y. Song ◽  
Q.Y. Sun ◽  
L. Xiao ◽  
L. Liu ◽  
H. Wang ◽  
...  
Keyword(s):  
Cold Deformation ◽  
Aging Treatment ◽  
Beta Phase ◽  
Optical Microscope ◽  
Alpha Phase ◽  
Slip Bands ◽  
Solution Treated ◽  
Plate Shape ◽  
Refinement Mechanism ◽  
Network Pattern

The influence of prior cold deformation on precipitating of alpha phase as well as the variation of hardness during aging has been investigated in solution-treated Ti-10Mo-8V-1Fe-3.5Al alloys. The results show that alpha phase precipitation could be obviously accelerated by the prior cold deformation. In the predeformed samples, a network pattern structure was observed with an optical microscope after aging treatment. It could be attributed to the phenomenon that the plate-shape alpha precipitates prefer to nucleate and grow in the regions with a high density of dislocations, especially inside slip bands. The hardness of both the predeformed and undeformed TB3 specimens after different aging times was measured and further predicted by a proposed strengthening model based on the grain refinement mechanism of the beta phase. The predicted results are consistent with the experimental results, especially in the later aging stages.

Synthesis of New Nitrides Using Solid State Oxide Precursors

1993 ◽  
Vol 327 ◽  
Author(s):  
Joel D. Houmes ◽  
David S. Bem ◽  
Hans-Conrad Zur Loye
Keyword(s):  
Solid State ◽  
Magnetic Measurements ◽  
Reaction Times ◽  
Magnetic Ordering ◽  
Beta Phase ◽  
Alpha Phase ◽  
Transition Metal Nitrides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trigonal Prismatic Coordination

AbstractSeveral novel transition metal nitrides were synthesized via ammonolysis of solid state oxide precursors at temperatures ranging from 700°C-900°C and reaction times ranging from 12 hours to 4 days. Both intermetallic nitrides, Fe3Mo3N and Co3Mo3N, and ionic/covalent nitrides, FeWN2, MnWN2, Ta5N6 and Nb5N6, were prepared by this method. The products were characterized by powder X-ray diffraction and their structures were determined by powder X-ray Rietveld refinement. The intermetallic nitrides were found to be isostructural with the eta-carbide structure, Fe3W3C, while the ionic/covalent nitrides have layered structures, with metals in octahedral and trigonal prismatic coordination environments. Two polymorphs of the MnWN2 composition, α-MnWN2 and β-MnWN2, were isolated after ammonolysis at 700°C and 800°C, respectively. While the alpha phase can be converted into the beta phase by heating to 800°C under ammonia, annealing the beta phase at 700°C did not result in a structural transformation. Magnetic measurements show that FeWN2 orders antiferromagnetically at 45K. The magnetic ordering temperature was confirmed by M6ssbauer spectroscopy. All the other nitrides were paramagnetic down to 5K. Conductivity measurements show that FeWN2 and MnWN2 are metallic.

The Characterization Of Organic Charge Transfer Superconductors By Microreflectance Spectroscopy

1990 ◽  
Vol 48 (2) ◽  
pp. 272-273
Author(s):  
S. L. Hill ◽  
K. Krishnan ◽  
J. R. Ferraro
Keyword(s):  
Charge Transfer ◽  
Single Crystal ◽  
Beta Phase ◽  
Alpha Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Crystallography ◽  
A Value ◽  
Charge Transfer Salts

Certain classes of organic charge-transfer salts demonstrate superconducting behavior at liquid helium temperatures. Single crystal x-ray diffraction and infrared microreflectance analysis have been performed on several conducting systems to associate the nature of the crystalline structure with the electrical conductivity. The infrared spectrum for a single crystal salt exhibits absorptions which correlate with superconducting behavior.Discussion Williams and coworkers have performed x-ray Crystallography experiments to demonstrate the presence of an anion cavity between radical cation stacks- of bis(ethylenedithio)- tetrathiafulvalene (ET). The sulfur…sulfur interstack distance in a beta or kappa phase salt assumes a value less than the Vanderwaals distance and exhibit a superconducting (two dimensional) metal behavior (verified by Fermi surface calculations) at 1-20K. The structures of alpha and beta phase ET2I3 suggest the potential for several potential intermolecular interaction modes. It may be observed that the beta phase permits both interstack as well as H … X anionic interactions, whereas these interactions are less likely to occur in the alpha phase.

Direct Alpha Ta Formation on TaN by Resputtering for Low Resistive Diffusion Barriers

2008 ◽  
Vol 8 (5) ◽  
pp. 2582-2587 ◽  
Author(s):  
Jung-Chih Tsao ◽  
Chuan-Pu Liu ◽  
Ying-Lang Wang ◽  
Kei-Wei Chen
Keyword(s):  
Surface Treatment ◽  
Resistivity Measurement ◽  
Beta Phase ◽  
Alpha Phase ◽  
Phase Changes ◽  
X Ray Diffraction ◽  
Body Center Cubic ◽  
Argon Ion Bombardment ◽  
Body Center ◽  
Two Phases

The Ta/TaN bilayer exhibits the best performance in the Cu metal multilevel interconnects, because it provides good coherence between Cu and dielectric layer. In the Ta/TaN bilayer, Ta has two phases: alpha-phase of body center cubic is preferred due to its lower resistivity (15–60 μΩ-cm), whereas beta-phase of tetragonal should be avoided due to high resistive (∼150–250 μΩ-cm). However, beta Ta most commonly forms on fcc TaN. Here we provide a simple scheme to bypass this high resistive phase by resputtering TaN prior to Ta deposition. We found that, with surface treatment by argon ion bombardment for enough time, alpha Ta phase can be directly formed, which is supported both by X-ray diffraction and resistivity measurement. Depth profiles of all elements from Auger electron spectroscopy reveals that the surface treatment induces a nitrogen deficient surface layer due to different sputtering yield, which causes phase changes from fcc TaN to hcp Ta2N followed by bcc Ta(N) and provide a favorable lattice constant for Ta alpha-phase formation.

scholarly journals Plastic deformation of beta-Ti-Mo alloys with isothermal omega phase

2020 ◽  
Vol 321 ◽  
pp. 11087
Author(s):  
Koichi Tsuchiya ◽  
Satoshi Emura ◽  
Xin Ji ◽  
Ivan Gutierrez ◽  
Toru Hara
Keyword(s):  
Volume Fraction ◽  
Shear Bands ◽  
Median Plane ◽  
Beta Phase ◽  
Significant Loss ◽  
Omega Phase ◽  
X Ray Diffraction ◽  
Ti Alloys ◽  
Metastable Beta ◽  
Hardness Values

Aging of metastable beta-Ti alloys leads to the precipitation of omega phase, resulting in a significant loss in ductility (omega brittleness). This presentation reports the results of 3D observations of isothermal omega phase by an orthogonal FIB/SEM system. It was revealed that the shape of omega phase particles varies with the particle size. By serial sectioning, it was possible to obtain a 3D image for the volume of several micrometer cube containing numerous omega particles. The volume fraction of omega phase was qualitatively determined. The value was much lower than the previous investigation by X-ray diffraction by Hickman in 1969. The SEM and TEM revealed the formation of shear bands in the cold rolled samples, where the shearing of omega phase and transformation into beta phase while maintaining the depletion of Mo was found. After the HPT deformation, white etching layers are formed near the median plane of the disc, where the omega phase particles were absent and exhibit significantly lower hardness values. These findings may help to clarify the cause of brittleness in beta Ti alloys with isothermal omega phase.

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