Purification of Niobium by Electron Beam Melting
Pure niobium metal, produced by alumino-thermic reduction of niobium oxide, contains various impurities which need to be reduced to acceptable levels to obtain aerospace grade purity. In the present work, an attempt has been made to refine niobium metals by electron beam drip melting technique to ac...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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De Gruyter
2016-06-01
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| Series: | High Temperature Materials and Processes |
| Subjects: | |
| Online Access: | https://doi.org/10.1515/htmp-2014-0218 |
| _version_ | 1818720473386582016 |
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| author | Sankar M. Mirji K.V. Prasad V.V. Satya Baligidad R.G. Gokhale A.A. |
| author_facet | Sankar M. Mirji K.V. Prasad V.V. Satya Baligidad R.G. Gokhale A.A. |
| author_sort | Sankar M. |
| collection | DOAJ |
| description | Pure niobium metal, produced by alumino-thermic reduction of niobium oxide, contains various impurities which need to be reduced to acceptable levels to obtain aerospace grade purity. In the present work, an attempt has been made to refine niobium metals by electron beam drip melting technique to achieve purity confirming to the ASTM standard. Input power to the electron gun and melt rate were varied to observe their combined effect on extend of refining and loss of niobium. Electron beam (EB) melting is shown to reduce alkali metals, trace elements and interstitial impurities well below the specified limits. The reduction in the impurities during EB melting is attributed to evaporation and degassing due to the combined effect of high vacuum and high melt surface temperature. The % removal of interstitial impurities is essentially a function of melt rate and input power. As the melt rate decreases or input power increases, the impurity levels in the solidified niobium ingot decrease. The EB refining process is also accompanied by considerable amount of niobium loss, which is attributed to evaporation of pure niobium and niobium sub-oxide. Like other impurities, Nb loss increases with decreasing melt rate or increase in input power. |
| first_indexed | 2024-12-17T20:23:24Z |
| format | Article |
| id | doaj.art-7a170175e7a843b290e79a054f856f53 |
| institution | Directory Open Access Journal |
| issn | 0334-6455 2191-0324 |
| language | English |
| last_indexed | 2024-12-17T20:23:24Z |
| publishDate | 2016-06-01 |
| publisher | De Gruyter |
| record_format | Article |
| series | High Temperature Materials and Processes |
| spelling | doaj.art-7a170175e7a843b290e79a054f856f532022-12-21T21:33:52ZengDe GruyterHigh Temperature Materials and Processes0334-64552191-03242016-06-0135662162710.1515/htmp-2014-0218Purification of Niobium by Electron Beam MeltingSankar M.0Mirji K.V.1Prasad V.V. Satya2Baligidad R.G.3Gokhale A.A.4Defence Metallurgical Research Laboratory, Hyderabad 500058, Telangana, IndiaNuclear Fuel Complex, Hyderabad 500062, Telangana, IndiaDefence Metallurgical Research Laboratory, Hyderabad 500058, Telangana, IndiaDefence Metallurgical Research Laboratory, Hyderabad 500058, Telangana, IndiaDefence Metallurgical Research Laboratory, Hyderabad 500058, Telangana, IndiaPure niobium metal, produced by alumino-thermic reduction of niobium oxide, contains various impurities which need to be reduced to acceptable levels to obtain aerospace grade purity. In the present work, an attempt has been made to refine niobium metals by electron beam drip melting technique to achieve purity confirming to the ASTM standard. Input power to the electron gun and melt rate were varied to observe their combined effect on extend of refining and loss of niobium. Electron beam (EB) melting is shown to reduce alkali metals, trace elements and interstitial impurities well below the specified limits. The reduction in the impurities during EB melting is attributed to evaporation and degassing due to the combined effect of high vacuum and high melt surface temperature. The % removal of interstitial impurities is essentially a function of melt rate and input power. As the melt rate decreases or input power increases, the impurity levels in the solidified niobium ingot decrease. The EB refining process is also accompanied by considerable amount of niobium loss, which is attributed to evaporation of pure niobium and niobium sub-oxide. Like other impurities, Nb loss increases with decreasing melt rate or increase in input power.https://doi.org/10.1515/htmp-2014-0218niobiumelectron beam meltingalumino-thermic reductiondrip melting |
| spellingShingle | Sankar M. Mirji K.V. Prasad V.V. Satya Baligidad R.G. Gokhale A.A. Purification of Niobium by Electron Beam Melting High Temperature Materials and Processes niobium electron beam melting alumino-thermic reduction drip melting |
| title | Purification of Niobium by Electron Beam Melting |
| title_full | Purification of Niobium by Electron Beam Melting |
| title_fullStr | Purification of Niobium by Electron Beam Melting |
| title_full_unstemmed | Purification of Niobium by Electron Beam Melting |
| title_short | Purification of Niobium by Electron Beam Melting |
| title_sort | purification of niobium by electron beam melting |
| topic | niobium electron beam melting alumino-thermic reduction drip melting |
| url | https://doi.org/10.1515/htmp-2014-0218 |
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