Abstract
Deformation behavior of four kinds of polycrystalline cordierites, fabricated by firing glass powder compacts at 1373K for 1h (heating rate of 6K/min or 20K/min) was characterized by a four-point-bending creep test. The powder compacts had a composition 2MgO⋅2Al2O3⋅5SiO2 and were eventually added with a small amount of ZrO2. The deformation of stoichiometric cordierite bodies obeyed a diffusional creep law at lower applied stresses, over the temperature range 1473-1523K. On the other hand, accelerate creep deformation was observed with increasing the applied stress and over the whole range of stress applied at 1573K, resulting from crack nucleation and coalescence. Deformation behavior, considered to be represented by the steady state creep rate over the temperature range 1423-1473K, was monitored in cordierite bodies added with 1.8mass% ZrO2 as a nucleation agent. However, this creep deformation was due to intergranular crack growth, whose opening increased proportional to time. Creep rupture of cordierite bodies added with ZrO2 occurred at lower applied stresses and temperatures as compared to stoichiometric cordierite bodies.
