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.

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.

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.

Phase Constitution and Heat Treatment Behavior of Ti-7mass% Mn-Al Alloys

2010 ◽  
Vol 654-656 ◽  
pp. 855-858 ◽  
Author(s):  
Masahiko Ikeda ◽  
Masato Ueda ◽  
R. Matsunaga ◽  
Mitsuo Niinomi
Keyword(s):  
Heat Treatment ◽  
Electrical Resistivity ◽  
Titanium Alloys ◽  
Beta Phase ◽  
Al Alloys ◽  
Omega Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Al Content ◽  
Solution Treated

Titanium exhibits many attractive properties. It is considered to be ubiquitous since it has the 9th-highest Clarke number of all the elements. However, the principal beta-stabilizing elements for titanium can be very expensive, making many titanium alloys expensive. Manganese is a beta stabilizer for titanium alloys and it is also considered to be ubiquitous since it has the 11th-highest Clarke number of all the elements. The behavior of Ti-Mn alloys during heat treatment has been investigated and it was found that in some alloys the isothermal omega phase is precipitated. Because this phase can lead to brittleness, it is very important to suppress its precipitation. Since it is well-known that aluminum suppresses isothermal omega precipitation, we investigated the effect of adding aluminum using Ti-7mass% Mn-0, 1.5, 3.0 and 4.5mass% Al alloys by performing electrical resistivity, Vickers hardness, and X-ray diffraction measurements. In solution-treated and water-quenched 0 and 1.5 alloys, only beta phase was identified, while hcp martensite and bate phase were identified in 3.0 and 4.5Al alloys. The resistivities at room and liquid-nitrogen temperatures were found to increase monotonically with increasing Al content. Isothermal  precipitation was suppressed by aluminum addition, while alpha precipitation was accelerated by Al addition.

Phase Constitution and Heat Treatment Behavior of Low Cost Ti-Mn System Alloys

2013 ◽  
Vol 551 ◽  
pp. 217-222 ◽  
Author(s):  
Masahiko Ikeda ◽  
Masato Ueda ◽  
Kaoru Imaizumi ◽  
Mitsuo Niinomi
Keyword(s):  
Heat Treatment ◽  
Titanium Alloys ◽  
Low Cost ◽  
Metallic Elements ◽  
X Ray Diffraction ◽  
Phase Constitution ◽  
Specific Strength ◽  
Good Biocompatibility ◽  
Fe Alloys ◽  
The Cost

This paper is a review of results for Ti-Mn [1], Ti-Mn-Al [2] and Ti-Mn-Fe [3] alloys that have been previously published. Titanium alloys, especially beta-type titanium alloys, have high specific strength, excellent corrosion resistance and good biocompatibility. Unfortunately, applications of titanium alloys are limited by their relatively higher cost. One reason is the use of rare and expensive metallic elements, such as vanadium and molybdenum, as a beta stabilizer. In order to reduce the cost, inexpensive and abundantly available metallic elements should be used as beta stabilizers. Manganese was adopted as a beta stabilizer because it is an abundant metallic element in the Earth’s crust and is relatively low in cost. The heat treatment behavior of Ti-Mn, Ti-Mn-Al and Ti-Mn-Fe alloys was investigated through electrical resistivity and Vickers hardness measurements, X-ray diffraction measurements to identify phase constitution, and observations using a light microscope [1], [2] and [3].

Development of Low-Cost Titanium-Manganese Shape Memory Alloys

2018 ◽  
Vol 941 ◽  
pp. 1254-1259
Author(s):  
Masahiko Ikeda ◽  
Masato Ueda
Keyword(s):  
Heat Treatment ◽  
Low Cost ◽  
Liquid Nitrogen Temperature ◽  
Al Alloys ◽  
X Ray Diffraction ◽  
Al Content ◽  
Orthorhombic Martensite ◽  
Β Phase ◽  
Heat Treated ◽  
Ice Water

Ti alloys are attractive materials for such applications, they are expensive due to the costly alloying elements such as Nb or Mo. The present authors have adopted Mn as a low-cost alloying element, and melted Ti-7, 7.5 and 8 mass%Mn-1.5 and 3mass%Al alloys using a laboratory-scale arc furnace. All specimens prepared from bottom ingots were heat treated at 1223 K for 3.6 ks and quenched in ice water. In the 7 and 7.5Mn-Al alloys, the β phase and orthorhombic martensite were identified using X-ray diffraction. In the 8Mn-Al alloys, only the β phase was identified. In the 7, 7.5, and 8Mn-Al alloys, the electrical resistivity at room and liquid nitrogen temperature increased with increasing Al content due to dissolution of Al into the β phase, whereas the Vickers hardness decreased with increasing Al content due to decreasing formation of athermal omega by the addition of Al. Heat treatment at 673 K for 60 s almost completely returned deformed Ti-7 and 7.5Mn-3Al specimens to their original shapes, and heat treatment at 773 K for 60 s almost returned deformed Ti-8Mn-Al specimens to their original shapes.

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.

Mechanical Properties of Ti-Mn-Al-Fe Alloys after Solution Heat Treatment

2014 ◽  
Vol 783-786 ◽  
pp. 597-601 ◽  
Author(s):  
Yoshinori Sumi ◽  
Shigeki Ueta ◽  
Masato Ueda ◽  
Masahiko Ikeda
Keyword(s):  
Mechanical Properties ◽  
Low Cost ◽  
Solution Treatment ◽  
Charpy Impact ◽  
Beta Phase ◽  
Β Phase ◽  
Ti Alloys ◽  
Solution Treated ◽  
Fe Alloys ◽  
Stabilizing Element

To develop a low-cost β Ti alloy, the influence of Mn in Ti-Al-Fe alloys on solution treatment behavior and mechanical properties was investigated. Although it has been known that Mn is a β stabilizing element in Ti alloys, Mn has not often been used for Ti alloys in spite of its low cost and sustainability so far, since Mn easily evaporates under low-pressure atmosphere, which is a common condition when melting Ti alloys. Therefore, general β Ti alloys include a high amount of expensive elements such as V, Mo and Nb to stabilize the β matrix phase. In this paper, Ti-8 to 10Mn-1Fe-3Al alloys (mass%) were produced by cold crucible levitation melting under atmospheric pressure to inhibit Mn loss by vaporization. As results, it was found that the β transus was lowered with increasing Mn amount, but the full β phase was obtained in solution-treated alloys over 1113 K, even in the 8%Mn alloy. Through tensile and Charpy impact tests of the full beta-phase samples, the ductility and toughness increase monotonically with increasing Mn amount from 8 to 10% in spite of the tensile strength having almost constant value. Ti-10Mn-1Fe-3Al alloy has the best mechanical properties among the alloys used in this study.

Effect of Heat Treatment on Microstructure and Corrosion Resistance of Ni-Cr-Mo-Fe Alloys

2012 ◽  
Vol 581-582 ◽  
pp. 773-776
Author(s):  
Er Chao Ding ◽  
Zhen Yong Man ◽  
Xin Xin Yang ◽  
Jing Tai Zhao
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Electrochemical Analysis ◽  
X Ray Diffraction ◽  
Homogeneous Microstructure ◽  
X Ray ◽  
Arc Melting ◽  
Distribution Of Elements ◽  
Microstructure Morphology ◽  
Fe Alloys

The effects of heat treatment on microstructure and corrosion resistance of Ni-Cr-Mo-Fe nickel-based alloys were investigated by X-ray diffraction (XRD), metallographic microscope (MM), scanning electron microscopy (SEM) and electrochemical analysis, respectively. Experimental results indicated that the samples which were prepared via electric arc melting shielded by argon were pure solid solutions with homogeneous microstructure. Segregation of chromium element and slightly smaller grain size were found after heat treatment. Better corrosion resistance of samples was achieved after heat treatment, due to improvement of microstructure, morphology and distribution of elements.

Enhancement of Characteristics of a Touch Sensor by Controlling the Multi-Layer Architecture of a Low-Cost Metal Mesh Pattern

2015 ◽  
Vol 15 (10) ◽  
pp. 7645-7651 ◽  
Author(s):  
Seung-Hoon Kwak ◽  
Min-Gi Kwak ◽  
Byeong-Kwon Ju ◽  
Sung-Jei Hong
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Corrosion Resistance ◽  
Low Cost ◽  
Optical Transmittance ◽  
Good Adhesion ◽  
Metal Mesh ◽  
Practical Applications ◽  
Dc Sputtering ◽  
Touch Sensor

In this study, the characteristics of a metal mesh touch sensor were enhanced by optimizing the multi-layer architecture of the metal mesh pattern. Low-cost metal such as an aluminum (Al) layer was mainly applied to the architectures for practical applications in touch screen panel (TSP) industries. As well, molybdenum (Mo) was added to the architectures in order to minimize the drawbacks of Al. Three types of Mo/Al, Al/Mo and Mo/Al/Mo layers were fabricated by DC sputtering. The thickness of the Al and Mo layer was optimized at 150 and 30 nm, respectively. Low sheet resistance below 0.27 Ω/□ was achieved with good adhesion on a glass substrate. Especially, in the case of architectures in which the Al layer was covered with an Mo layer, thermal stability and corrosion resistance was enhanced. The change in resistance of the Mo/Al/Mo architecture was less than 0.056 even after heat-treatment at 260 °C. By using the optimized layer architecture, the mesh pattern with a 4 μm line width showed good optical transmittance (86.7%) and reflectivity (13.1%) at 550 nm, respectively. Also, a touch sensor fabricated by using the Mo/Al/Mo mesh pattern operated well indicating that the mesh pattern is feasible in a TSP application.

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