Structure and mechanical properties of ZrO<inf>2</inf> (MgO) — CaSiO<inf>3</inf> composites

Abstract

Composites based on zirconium and wollastonite has structural properties, which combines good mechanical properties, thermal resistance and high hardness, as well as the ability to withstand considerable compressive stress. The developed techniques improve the toughness provide for the inclusion of wollastonite (CaSiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) fiber “whiskers” the increase in fiber content improves strength and toughness, the volume of wollastonite (CaSiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) 1-25%. Sintering is the process of processing used to produce materials with controlled density and details of the ceramic. Raising the temperature led to an increase in the density of ceramic composites, a structure that combines the high mechanical properties, thermal resistance and high hardness, as well as the ability to withstand considerable compressive stress. It is shown that the maximum density and hardness is achieved at the sintering temperatures 1400-1500°C, thus there is a transformation of tetragonal zirconia in a mixture of three phases of the cubic, tetragonal and monoclinic, and monoclinic is the main phase containing up to 90%. It is shown that the maximum material strength is reached at 5-10% wollastonite, sintered at 1300°C. Estimated activation energy of sintering, which is equal to 50 kJ/mol, corresponding to the mechanism of surface diffusion.