- Details
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Category: Tungsten Information
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Published on Thursday, 05 February 2015 18:26
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Written by cq
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Hits: 1474
In these years, significantly incremental enhancements and specialized developments in the area of hardmetal continued shift towards ultra-fine and ultra-coarse grades. Compared with conventional cemented carbide (middle grain or fine grain carbides), ultra-coarse grain cemented carbides(>5µm) demonstrate good fracture toughness and thermal fatigue resistance. Thus, they attract much attention from different departments in the area of industry. Currently, it is widely applied in many fields and found increasing usage in areas such as milling tools, punching dies, and boring drills. Coarse grain W and WC powders are key materials for ultra-coarse grain cemented carbides producing. The industrially established method of preparing tungsten and carbide is the hydrogen reduction of tungsten oxide, tungstic acid or ammonium para tungstate at 900-1 200℃ or even higher temperature, initially to the metal powder followed by carburization. The average particle size of the powder obtained in this way is below 12 µm (Fsss).