Refractory metals: Tungsten, tantalum, columbium, and rhenium

Pugh, J. W.

doi:10.1007/bf03398215

Cited by 10 publications

(6 citation statements)

References 7 publications

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“…[2,12] Pugh [2] measured the harders. [1,23,28] Es-Said et al [23] observed an increase in hardness, ening rate of rhenium to be almost 3.5 times that of molybdetensile strength, and yield strength by a factor of 3 when num and tungsten.…”

Section: Resultsmentioning

confidence: 99%

“…ing point (second only to tungsten), creep strength superior to any other metal, high strength at elevated temperatures, good ductility, and corrosion and wear resistance. [1,2] In II. MATERIALS recent years, the interest in rhenium metal has grown considRhenium plates of various thicknesses ranging from 1.5 erably due to its wide spread use in high-temperature applicato 5 mm were obtained from Ultramet (Pacoima, CA).…”

Section: Introductionmentioning

confidence: 99%

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Influence of cold rolling and strain rate on plastic response of powder metallurgy and chemical vapor deposition rhenium

Koeppel

Subhash

1999

Metall Mater Trans A

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The plastic response of two kinds of rhenium processed via powder metallurgy (PM) and chemical vapor deposition (CVD) were investigated under uniaxial compression over a range of strain rates. The PM rhenium, further cold rolled to 50 and 80 pct of the original thickness, was also investigated to assess the influence of cold work on the plastic behavior. A strong basal texture was detected in all the preceding materials as a result of processing and cold work. Both CVD and PM rhenium exhibited an increase in yield strength and flow stress with increasing strain rate. In PM rhenium, cold work resulted in an increase in hardness and yield strength and a decrease in the work hardening rate. The deformed microstructures revealed extensive twinning in CVD rhenium. At large strains, inhomogeneous deformation mode in the form of classical cup and cone fracture was noticed.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Influence of cold rolling and strain rate on plastic response of powder metallurgy and chemical vapor deposition rhenium

Koeppel

Subhash

1999

Metall Mater Trans A

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“…With approximately 35 percent ductility as measured in elongation, and a tensile strength dropping from 1,172 MPa at room temperature to 48 MPa at 2,7008C, rhenium is virtually inert to thermal shock (Sims et al, 1956). Of the refractory metals, rhenium has the greatest tensile and creep-rupture strength at elevated temperatures (Pugh, 1958). Rhenium also possesses a wear resistance second only to osmium among the metallic elements (Duchart et al, 1946), and the highest strain hardening coefficient of any metal.…”

Section: Multilayer Rhenium Coating Using Cvdmentioning

confidence: 99%

Rapid manufacturing of rhenium components using EB‐PVD

Prabhu

Fuke

Cho

et al. 2005

Rapid Prototyping Journal

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Rapid manufacturing of rhenium components using EB-PVD Vittal V. Prabhu Indraneel V. Fuke Sohyung Cho Jogender Singh Article information:To cite this document: Vittal V.If you would like to write for this, or any other Emerald publication, then please use our Emerald for Authors service information about how to choose which publication to write for and submission guidelines are available for all. Please visit www.emeraldinsight.com/authors for more information. About Emerald www.emeraldinsight.comEmerald is a global publisher linking research and practice to the benefit of society. The company manages a portfolio of more than 290 journals and over 2,350 books and book series volumes, as well as providing an extensive range of online products and additional customer resources and services.Emerald is both COUNTER 4 and TRANSFER compliant. The organization is a partner of the Committee on Publication Ethics (COPE) and also works with Portico and the LOCKSS initiative for digital archive preservation. AbstractPurpose -The purpose of this paper is to provide insights for understanding the relationship between rapid manufacturing process for rhenium components in jet nozzle fabrication using electron beam-physical vapor deposition (EB-PVD). Specifically, to develop a methodology to characterize and improve this new process through motion planning for maintaining uniformity in the deposition thickness. Design/methodology/approach -This research first identifies several important objectives for the process, and then develops an optimized heuristic method based on a look-ahead approach to generate motion plans for uniform thickness objective. In this heuristic, the surface of the workpiece is modeled using finite element method and the accumulated thickness of each layer on each element is computed based on its location in the vapor plume using a ray casting algorithm. Findings -Computational experiments show that the proposed algorithm can potentially provide significant improvements in the uniformity of the layers and cost savings in manufacturing compared to prevailing practice, especially for low-volume production such as aerospace applications.Research limitations/implications -In this research, net-shaped jet nozzle has been fabricated using a graphite mandrel. Therefore, the mandrelbased approach can be limited to producing hollow components. Practical implications -The proposed method is very generic and thus can be applied for multi-material manufacturing process identifying the sweet spot of the intersecting vapor plumes. Originality/value -This research can help the EB-PVD process for rapid manufacturing which has been considered as financially expensive to be accepted in real practice by providing a relationship of the process-to-product transformation through the developed motion planning methods.

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“…It is a refractory metal with a very high melting point (3180°C) and is resistant to wear and corrosion even at low pH and high salt condition . Among the refractory metals (niobium, molybdenum, tantalum and tungsten), Re element exhibits the greatest tensile and creep‐rupture strength . Moreover, Re does not form carbides, nor does it have a ductile‐to‐brittle transition temperature as it is ductile over a wide range of temperatures .…”

Section: Introductionmentioning

confidence: 99%

“…[11][12][13] Among the refractory metals (niobium, molybdenum, tantalum and tungsten), Re element exhibits the greatest tensile and creep-rupture strength. 11,14 Moreover, Re does not form carbides, nor does it have a ductile-to-brittle transition temperature as it is ductile over a wide range of temperatures. 13 Thus, it has the capability to be utilized in various applications.…”

Section: Introductionmentioning

confidence: 99%

Neutron‐activatable needles for radionuclide therapy of solid tumors

Kim

Narayan

Lü

et al. 2017

J Biomedical Materials Res

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Various approaches have been undertaken to enhance the delivery of therapeutic agents, including tissue-killing radionuclides, into solid tumors. Here we describe the preparation of conical needles composed of Ti and Mo coated by pulsed laser deposition or chemical vapor deposition with elements (Ho and Re) that can readily yield radioactive isotopes following irradiation in a neutron flux. The radioactive needles, whose design were based on solid microneedle arrays used in transdermal drug delivery, can be produced with minimal handling of radioactivity and subsequently inserted into tumors as a means of internal radiation therapy. Ho and Re, were specifically chosen because of their large neutron capture cross-sections as well as the desirable radiotherapeutic properties of the resultant radionuclides. Neutron-absorbing shields were also developed to prevent the production of unwanted radionuclides after neutron irradiation of the needle base materials. Neutron activation calculations showed that therapeutically significant amounts of radionuclides can be produced for treating solid tumors. Stability studies demonstrated that Re did not leach off the Mo needles. These coated neutron-activatable needles offer a new approach to internal radiation therapy of tumors that allows precise tailoring of the absorbed radiation dose delivered to the tumor by controlling the coating thickness and the irradiation time.

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Refractory metals: Tungsten, tantalum, columbium, and rhenium

Cited by 10 publications

References 7 publications

Influence of cold rolling and strain rate on plastic response of powder metallurgy and chemical vapor deposition rhenium

Influence of cold rolling and strain rate on plastic response of powder metallurgy and chemical vapor deposition rhenium

Rapid manufacturing of rhenium components using EB‐PVD

Neutron‐activatable needles for radionuclide therapy of solid tumors

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