The influences of Cr3C2 addition on the phase formation and mechanical properties of (Zr,Ti,Nb,Ta,Hf)C

The influences of Cr 3 C 2 addition on phase formation, microstructures and mechanical properties of (Zr,Ti,Nb,Ta,Hf)C prepared from binary carbides mixtures by spark plasma sintering were studied. The introduction of 4/3 mol.% Cr 3 C 2 significantly lowered the minimum temperature for uniform high-entropy phase (Zr,Ti,Nb,Ta,Hf)C from 2200 °C for to 1900 °C. The lower solubility limit of Cr in (Zr,Ti,Nb,Ta,Hf,Cr)C results in excessive Cr 3 C 2 -based carbides, which tends to segregate along grain boundaries at higher sintering temperatures while locate at triple junctions at lower sintering temperatures . High mechanical strength of 599 MPa were obtained when 4/3 mol.% Cr 2 C 3 was added and sintered at 1900 °C. The fine grain size and Cr 3 C 2 -based carbides are responsible for the high mechanical properties. More Cr 2 C 3 addition results in lower mechanical properties due to excessive Cr 3 C 2 -based carbides.