Multi-Objective Optimization of Extrusion Parameters for High-Performance Honeycomb Cordierite Ceramics via Orthogonal Design

Cordierite diesel particulate filters (DPFs) were prepared using pure cordierit powder with organic binders, sodium silicate aids and pore formers by extrusion technique. The orthogonal test method was adopted to investigate the optimal value of the multi-objective and multi-factor problems. Based on results from statistical analysis, sintering temperature is the most important factor. The optimal parameters included a 3 h holding time, 10 wt.% pore former, 12 wt.% sintering aid, and a sintering temperature of 1150 °C. As the sodium silicate liquid increased and viscosity decreased with the increasing of temperature, which led to the formation of glass phases and the improvement of density. Therefore, with increasing sintering temperature, the porosity and coefficient of thermal expansion decreased. Both the mechanical properties and chemical stability of the prepared samples are strengthened. When the sintering temperature was 1150 °C, the prepared samples with high porosity (67.82%), compressive strength (5.88 MPa), bending strength (13.10 MPa), low thermal expansion coefficient (CTE, 1.82×10-6/oC) showed the best comprehensive performance of thermal shock resistance and filtration efficiency. These results demonstrate great potential for DPF applications and provide a refrence for the design of other honeycomb ceramics with optimum level of liquid phase.