Cemented carbide(s) with improved hardness and toughness - produced by sintering under high pressure

摘要

Hard alloy articles, comprising gp. IVa, Va or VIa metal carbide(s) in an iron gp. metal binder, are produced by pressing, opt. pre-sintering and sintering at 1300-1500 degrees C under 8000-40000 bars pressure. Method is esp. useful in prodn. of cutting tools and produces a very fine grain structure resulting in increased hardness and toughness. In an example, ISO K10 alloy (94.5% WC/5.5% Co) powder was compacted at 1000 bars pressure into cylindrical specimens of dia. 4.5 mm, height 4.5 mm and density 8g/cm3, heated at 100 degrees C/min to the sintering temp., sintered under an isostatic pressure of 25000 bars and rapidly cooled.