Effect of zirconia stabilized with ceria in the mechanical properties of alumina composites

Abstract

Coatings for machinery and equipment, in consequence of industrial processes, are demaged by erosion, impact and chemical attack, which lead to frequent production shutdown for maintenance actions. This fact encourages the development of higher strength materials to attend the processing needs. The addition of zirconium and cerium oxides into alumina based compounds has shown promising results as to increase the modulus properties of ceramic such as strength, density and hardness. In this context, the objective of this work was to study the influence of the addition of ceria partially stabilized zirconia (ZPEC, 3-10%) in alumina based composites. To obtain these compounds, aluminum oxide, cerium oxide and zirconium oxide were mixed in a ball mill and formed by cold isostatic pressing, dried and sintered at 1500 or 1600 °C. The raw materials were characterized by XRD and laser granulometry. Mechanical properties, density, porosity, strength and hardness of the materials after sintering were evaluated by linear shrinkage, apparent porosity and density and flexural strength. As a compound to be used as coating which will be subject to erosive wear, the erosion rate was determined by applying a test based on ASTM G-76. The results indicate that the increase in ZPEC content in the alumina-based composites tends to increase the values of resistance to erosive attack, density and flexural strength of these materials, which are important properties for application of materials in industrial environments.

Keywords: alumina, ceria-stabilized zirconia, mechanical properties.