The Microstructure of Polycarbide Based Hard Alloys

摘要

Polycarbide based hard alloys may replace carbide tungsten based hard alloys in the processesrnof finished and semi-finished turning as well as under condition of intensive wear. Thernmicrostructure and phase composition of TiC-(VC, NbC, WC) polycarbide based hard alloysrnwith nickel-chromium binder and various ratios of carbides and binder were investigated. Thernhard alloys were manufactured by the conventional method (wet milling of the initialrnpowders, cold pressing and vacuum sintering) and a new developed technology, whichrnincludes an additional operation - the preliminary synthesis of the complex carbide. Therninteraction of the components was investigated by metallographic, XRD and SEM analysis.rnThe specific core/rim structure of carbide grains was determined. The effect of technology onrnthe formation of the microstructure of the TiC-(VC, NbC, WC) based hard alloys and therninfluence of the latter on the mechanical properties were investigated.