Alloying titanium and tantalum by cold crucible levitation melting (CCLM) furnace

Morita, Arimichi; Fukui, Hisao; Tadano, Hideaki; Hayashi, Shizuo; Hasegawa, Jiro; Niinomi, Mitsuo

doi:10.1016/s0921-5093(99)00668-1

Cited by 70 publications

(38 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The melting method has two merits for Ti alloys. Levitation allows the alloys to be melted without contamination and the strong electromagnetic stirring produces an alloy with uniform composition [19]. The prepared Ti-25 at % Nb base alloy ingots were segmented and remelted in the same cold-crucible furnace, which was followed by the addition of TiO 2 powder in order to obtain the desired Ti-25 Nb-O alloys with different oxygen concentrations.…”

Section: Methodsmentioning

confidence: 99%

Snoek‐Type High‐Damping Alloys Realized in β‐Ti Alloys with High Oxygen Solid Solution

et al. 2006

View full text Add to dashboard Cite

High-damping alloys are finding more and more applications as a passive damping measure in mechanical structures in attempts to eliminate noise and vibration, especially in circumstances where traditional structural damping or system damping methods are not suitable, for example, in high-temperature environments.[1] High-damping alloys have the ability to damp out noise and vibration, and are expected also to possess adequate mechanical properties such as rigidity and strength. In high-temperature working environments, both high damping capacity and strength at elevated temperatures are required. The damping capacity of high-damping alloys (equivalent to the internal friction of a material) is defined as the capacity of a material to convert its mechanical energy of vibration into heat, which is dissipated in the material. With the exception of thermoelastic damping, the majority of damping mechanisms are associated with the stress-induced movement of crystalline defects. Point defects give rise to damping in the range of low to intermediate levels, dislocations give rise to damping levels in the intermediate to high range, and planar defects (twin boundaries and magnetic domain boundaries) give rise to damping levels in the high range.[2] Three groups of high-damping alloys have been developed in the past 50 years, which apply the mechanisms of dislocation damping, ferromagnetic damping, and twinboundary damping, respectively. However, there are some deficiencies in the damping behavior of the alloys, which have affected the application of high-damping alloys. In the case of dislocation-type damping alloys, rearrangement of the pinning points during continued vibration leads to a damping capacity that varies with service time. [2] Similarly, for twin boundarytype damping alloys, it is reported that degradation of damping capacity occurs when they are held at room temperature, which is induced by the diffusion of interstitial carbon atoms to the twin boundaries.[3] And for ferromagnetic high-damping alloys, the damping capacity will be considerably reduced in the presence of a magnetic field or a static load. While the optimization of the damping microstructure is an important research topic for the already developed high-damping alloys, [4][5][6] it is noted that both dislocation damping and boundary damping are influenced by the interstitial impurities in the alloys. While interstitial impurities are easily introduced into the alloys in the conventional fabrication processes, no work has been done to show the advantage of interstitial solid solution atoms in improving the damping capacity of those alloys. We took up the challenge of obtaining a high damping capacity in alloys by making use of the interstitial solid solution atoms. Point defects in crystalline solids can generate a time-dependent strain under the application of an external stress due to the reorientation of the point defects. This phenomenon was experimentally investigated in body-centered cubic (bcc) metals with interstitial impurities of carbo...

show abstract

Section: Methodsmentioning

confidence: 99%

Snoek‐Type High‐Damping Alloys Realized in β‐Ti Alloys with High Oxygen Solid Solution

et al. 2006

View full text Add to dashboard Cite

show abstract

“…Titanium and tantalum ingots were obtained in the same way. The obtainment of Ti-Ta alloys by conventional arc-melting is difficult [12] due to the great difference between the melting point and density of both titanium and tantalum (respectively 1702 8C and 4.51 g cm À3 for titanium and 2996 8C and 16.6 g cm À3 for tantalum) and the relatively large two-phase (liquid þ solid) field in the binary Ti-Ta phase diagram [13]. The latter factor leads to a great segregation during solidification and to the necessity of thermal treatment for homogenization.…”

Section: Methodsmentioning

confidence: 99%

Electrochemical behavior of titanium‐tantalum alloys in sulfuric acid solutions

Souza¹,

Robin²

2004

Materials & Corrosion

View full text Add to dashboard Cite

Titanium exhibits a good corrosion resistance in oxidizing acids and neutral media but it is severely attacked in reducing acids. On the contrary, tantalum presents an excellent resistance in both oxidizing and reducing acids, but its high cost limits its use to very aggressive conditions. The titanium-tantalum alloys are promising materials for use in reducing acids, due to their lower cost and density when compared to tantalum, and their higher corrosion resistance when compared to titanium. Titanium-20, 40, 60 and 80 wt% tantalum alloys were prepared by arc-melting and their microstructures were characterized by scanning electron microscopy and Xray diffractometry. Their electrochemical behaviors were studied in 20 to 80 wt% sulfuric acid solutions at room temperature, using open-circuit potential measurements, potentiodynamic polarization and electrochemical impedance spectroscopy. Different behaviors were observed depending on the tantalum content and acid concentration. A clear tendency of increase in corrosion resistance with the increase of tantalum content is observed, especially in 80 wt% sulfuric acid solutions.

show abstract

“…Crucible cooling is also a reason for a solidified layer formation that does not allow any contact of the remaining material with the crucible wall. Moreover, the melted metal partly levitates due to Lorentz forces [20][21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

The Influence A Crucible Arrangement On The Electrical Efficiency Of The Cold Crucible Induction Furnace

Smalcerz

Oleksiak

Siwiec

2015

Archives of Metallurgy and Materials

View full text Add to dashboard Cite

A big interest in application of cold crucible furnace (CCF) for industrial, particularly metallurgical, processes has been observed in recent years. They are mainly utilised for melting of metal, glass and other materials. Analyses of processes that occur in such devices are performed; however, computer modelling is rarely applied. As a precise determination of the electromagnetic field distribution is essential for a proper analysis of processes in furnaces with cold crucibles, a complex 3D model development is necessary. In the paper, effects of a crucible design and current frequency on the efficiency of the induction furnace with cold crucible are presented. Numerical calculations were performed with the use of the Flux 3D professional software.

show abstract

Alloying titanium and tantalum by cold crucible levitation melting (CCLM) furnace

Cited by 70 publications

References 2 publications

Snoek‐Type High‐Damping Alloys Realized in β‐Ti Alloys with High Oxygen Solid Solution

Snoek‐Type High‐Damping Alloys Realized in β‐Ti Alloys with High Oxygen Solid Solution

Electrochemical behavior of titanium‐tantalum alloys in sulfuric acid solutions

The Influence A Crucible Arrangement On The Electrical Efficiency Of The Cold Crucible Induction Furnace

Contact Info

Product

Resources

About