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The Tungsten Carbide Involving the Nano Metal Cobalt Domains Synthesized by Carburizing the Cobalt Supersaturated‐Tungsten Powder with CO Gas
Author(s) -
Morishita Masao,
Yamamoto Hiroaki,
Okahira Tokitake,
Yoshioka Motohide,
Fukumuro Naoki,
Matsuda Hitoshi,
Ikebe Masaaki,
Iwasaki Masahiro,
Yanagita Hidefumi,
Nishimaki Hiroshi
Publication year - 2012
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.12015
Subject(s) - cobalt , materials science , tungsten carbide , microstructure , hard metal , high resolution transmission electron microscopy , tungsten , cobalt oxide , carburizing , carbide , chemical engineering , metallurgy , oxide , metal , transmission electron microscopy , analytical chemistry (journal) , nanotechnology , chemistry , chromatography , engineering
The WC involving the nano metal cobalt domains has been prepared by a gas‐solid reaction between the cobalt nonequilibrium supersaturated‐tungsten powder and carbon mono‐oxide gas ( CO ). The metal Co domains formed in the WC were found to be spherical with a diameter of approximately 60 nm by observing the microstructure with a high‐resolution transmission electron microscope ( HRTEM ). The 88.36 mass% WC – 11.64 mass% Co hard metal was prepared by liquid‐phase sintering at 1623 K from the powder compact which was mixture of the WC involving the Co domains and the cobalt powder as binder phase. A nano‐scale fine structure composed of the WC with average diameter, d Av , of approximately 500 nm was obtained. Its Vickers hardness was found to be Hv 1663 ± 43, being nearly equal to the 95.5 mass% WC –4.5 mass% Co with 1–2 μm WC grains. That is, reduction of 7 mass% WC was accomplished. The WC involving the Co domains is expected to be used as raw materials to form the nano‐scale microstructure in the hard metals, resulting in reduction in W components.