Effect of agglomeration and calcination temperature on the mechanical properties of yttria stabilized zirconia (YSZ)

Abstract

Effect of azeotropic distillation after co-precipitation process of powder synthesis on powders morphology and mechanical properties of yttria stabilized zirconia was studied. The formation of hard or soft agglomerates during drying or calcination of co-precipitated powder can easily be prevented through azeotropic distillation. The powder prepared by direct co-precipitation and azeotropic treatment after co-precipitation process was calcined at different temperatures and was characterized through X-ray diffraction, transmission electron microscope and BET surface area measurement. The calcined powders were compacted uniaxially and sintered in two step sintering process. Sintered, polished and thermally etched samples were observed under scanning electron microscope. Vickers hardness and indentation fracture toughness were estimated. It is observed that reasonably higher density with better hardness and fracture toughness can be achieved for azeotroped samples in same sintering condition. Azeotropic treatment increases the surface area almost three times which helps to achieve better sintering. Pin on disc wear tests against alumina disc at 20 N and 50 N loads up to 3000 m distance were carried out. The wear depth and coefficient of friction for both the material were compared.