Diffusion parameters of grain-growth inhibitors in WC based hardmetals with Co, Fe/Ni and Fe/Co/Ni binder alloys

Abstract

Highlights ► Cr diffusion in hardmetals Independent from binder alloy in early sintering stages ► Nitrogen reduces solubility and diffusivity of Cr and V in hardmetals ► Diffusion in hardmetal green bodies is faster than in equilibrated hard metals ► No (W,V)C layer is observable on WC at 1050 °C ► A valuable grain size for VC and Cr 3 C 2 for hardmetal sintering was estimated

The evaluation Of The Non-Toxic Ferrous Matrix Based WC Reinforced Composites: A Review

“…Conversely, in the M12C type, it occurs in the form of small grains scattered all over the matrix when cooling after solidification. Due to the increased grain limit, it provides high strength and less brittleness [28][29][30].…”

“…When the results are evaluated in microstructural and mechanical properties, chemical composition, and process conditions are well determined, these alloy systems could achieve comparable or even superior properties to Co-containing binders. [29]. Also, by carefully controlling the Fe-Ni composition ratio, carbon content, and thermodynamic processes, the desired degree of stability of the binding phase could be achieved.…”

Structure and Magnetic Properties of WC–50% Co Model Alloys Containing TaC Additives

“…Эффективным способом подавления процесса перекристаллизации через жидкую фазу является введение в состав сплава ингибиторов роста карбидного зерна (ИРКЗ), среди которых наиболее сильным ингибирующим эффектом обладают карбиды переходных металлов VC, Cr 3 C 2 , TaC, NbC, ZrC и др. [8][9][10][11][12][13]. Суммарное содержание ИРКЗ в твердых сплавах обычно меньше их предела растворимости в связующей фазе, что позволяет избежать выделения избыточных карбидных фаз на основе ИРКЗ, негативно влияющих на механические свойства твердых сплавов, в частности предел прочности при изгибе.…”

Experimental investigation and thermodynamic assessment of the C–Co–Fe–Ni–W system

“…Also, an increasing demand for hardmetals accompanied by the increasing Co shortage and the high cost requires solution. In this aspect, the alternative binder (Fe,Co,Ni), which replaces at least a portion of Co by Fe or Ni, is of growing interest in the preparation of hardmetals [6][7][8][9][10].…”