WC/Co 초경 스크랩 산화물의 환원/침탄 반응 |
권철민1, 이길근1, 하국현2 |
1부경대학교 신소재시스템공학과 2한국기계연구원부설 재료연구소 |
Carbothermal Reduction of Oxide of WC/Co Hardmetal Scrap |
CheolMin Kwon1, Gil-Geun Lee1, Gook-Hyun Ha2 |
1Department of Materials System Engineering, Pukyong National University, Busan 48547, Republic of Korea 2Powder Technology Department, Korea Institute of Materials Science, Changwon 51508, Republic of Korea |
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Received: 18 April 2016; Accepted: 10 May 2016. Published online: 5 October 2016. |
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ABSTRACT |
This study conducted an analysis of the carbothermal reduction of oxidized WC/Co hardmetal scrap with solid carbon under an argon and hydrogen gas atmosphere. The WC/Co hardmetal scrap oxide consisted of WO3 and CoWO4. WO3 was reduced before CoWO4 by the solid carbon regardless of gas atmosphere. The simple oxide WO3 transformed to a tungsten carbide phase without the formation of tungsten under the argon atmosphere. However, WO3 reduced to tungsten and then tungsten carbide was formed under the hydrogen atmosphere. Further, the complex oxide CoWO4 transformed to tungsten carbide and cobalt phases via a Co-W-C system complex carbide phase under the argon atmosphere. However, in contrast to the reaction under the argon atmosphere, under the hydrogen atmosphere an additional phase transformation route was observed, i.e., the formation of tungsten carbide and cobalt phases from CoWO4 through the formation of tungsten oxide and cobalt-tungsten alloy phases. The tungsten carbide formation under argon and hydrogen atmospheres occurred at about 950 ℃ and 850 ℃, respectively. |
Keywords:
powder, tungsten carbide, hardmetal, carbothermal reduction, phase transformation |
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