Fabrication and Mechanical Properties of Continuously Graded WSi2–ZrO2(2Y) Materials Using Wet-Molding

Continuously graded WSi2–ZrO2(2Y) materials with high density (99.2% of theoretical) have been fabricated by uniaxial wet-molding, followed by hot pressing (1000°C/1h/30MPa) and hot isostatic pressing (1500°C/2h/196MPa). A mixed solution of glycerin and ethanol with the viscosity of ≈6 mPa·s has been used as a dispersion medium in the molding process. The sintered materials show a linear composition profile with a transition from WSi2/ZrO2(2Y) ≈75/25 to ≈5/95 mol%. Vickers hardness, Hv, for which the value is ≈11.2 GPa, is almost independent of the compositional change. Fracture toughness, KC, increases from 5.6 to 10.3 MPa·m1/2 with increasing ZrO2(2Y) composition.