The effect of 3 mol% Y2O3 stabilized ZrO2 produced by a steric entrapment method on the mechanical and sintering properties of Cr3C2 based cermets

Abstract

The aim of the study was to increase the toughness and strength of the Cr3C2 based cermets without compromising other mechanical properties by reinforcing Cr3C2–NiCr with yttria stabilized tetragonal zirconia particles (3Y-TZP). The TZPs were produced by a steric entrapment process. Cr3C2–NiCr (master) and 2wt% 3Y-TZP reinforced Cr3C2–NiCr “73C2Z3” cermets were sintered and the sintering kinetics and resulting mechanical properties were determined. The master cermets were sintered to 97% of theoretical density at 1350°C while 73C2Z3 cermets achieved a relative density of 98.5% even at 1300°C. Elastic modulus, transverse rapture strength, hardness, and fracture toughness values were measured. For the master cermets, all mechanical properties showed an increasing trend by increasing the sintering temperature to 1350°C. On the other hand, the mechanical properties of 73C2Z3 cermets reached maximum or near maximum values at 1300°C. Moreover, 73C2Z3 cermets had higher strength and fracture toughness compared to that of the master cermets and this observation was attributed to smaller carbide grains, a homogeneous 3-D network structure of Ni–Cr metal binder phase and a good distribution of fine 3Y-TZPs.