The effect of 3 mol% Y_2O_3 stabilized ZrO_2 produced by a steric entrapment method on the mechanical and sintering properties of Cr_3C_2 based cermets

摘要

The aim of the study was to increase the toughness and strength of the Cr_3C_2 based cermets without compromising other mechanical properties by reinforcing Cr_3C_2-NiCr with yttria stabilized tetragonal zirconia particles (3Y-TZP). The TZPs were produced by a steric entrapment process. Cr_3C_2-NiCr (master) and 2 wt% 3Y-TZP reinforced Cr_3C_2-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℃ while 73C2Z3 cermets achieved a relative density of 98.5% even at 1300 ℃. 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℃. On the other hand, the mechanical properties of 73C2Z3 cermets reached maximum or near maximum values at 1300℃. 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.