Investigation of wear properties of CaO, MgO added stabilized zirconia ceramics produced by different pressing methods

Abstract

Stabilized zirconia has superior high temperature properties such as high tolerance for thermal shock, low thermal conductivity, mechanical properties, elevated melting point, good phase stability and excellent oxidation resisNtance. The present paper describes the fabrication and wear behaviour of 8 mole% CaO, 4 mole % CaO-4 mole% MgO and 8 mole% MgO - stabilized zirconia (ZrO2) based composites fabricated by the conventional ceramic production process. CaO/MgO added stabilized zirconia ceramics were fabricated by using a combined method of ball milling, cold press-cold isostatic pressing and sintering. The powder blends containing different amounts of % 8 mole CaO/MgO were wet-milled for 1 hr in a vibratory ball-mill using zirconia vial and balls. After drying, powders were compacted to cylindrical preforms with a diameter of 12.7 mm by uniaxial pressing at 300 MPa and by cold isostatic pressing at 300 MPa. The green compacts were sintered at 1600 degrees C for 3 hrs under air. Phase and microstructural characterizations of the sintered materials were carried out by using X-ray diffraction technique (XRD) and scanning electron microscope (SEM). The Micro Vickers hardness testing was performed using the Shimadzu HMV-MIII hardness tester. Plint brand abrasion tester was used for the abrasion tests of ceramics. As a result, it has been observed that the hardness is increased by increasing the amount of MgO and the ceramics produced by cold isostatic pressing are harder.