Study Of Preparation And Performance Of Honeycomb Cordierite Ceramic For Vehicle Catalyst Carrier

Cordierite (2MgO2-Al2O3-5SiO2), a ceramic material of low coefficient of thermal expansion (CTE) and excellent stability performance, can be used as catalyst carrier for vehicle exhaust, which has broad application prospects. However, most cordierite are synthetic due to low natural content. In foreign, low CTE cordierite has manufactured successfully by one-time sintering while in domestic, only relatively high CTE by two-time sintering can be fabricated.In this thesis, honeycomb cordierite ceramics, with a low CTE, good thermal shock resistance performance and high strength, were sintered from Suzhou earth, talc and alumina powder. The preparation process was studied including raw recipe, optimum sintering temperature and holding time as well as the influence of additives and acid-treatment. The phase composition was investigated by X-Ray diffraction (XRD) and the surface morphology and microstructure were observed by scanning electron microscope (SEM). The optimal preparation process was ultimately determined by comparing the CTE, sintering properties, compressive strength and other parameters. The results indicate that:1.When the mass fraction of MgO, Al2O3and SiO2is consistent with the stoichiometry of cordierite (13.7wt.%MgO,34.9wt.%A12O3and51.4wt.%SiO2), the sample has more cordierite content and the lower CTE and higher strength with the optimum sintering temperature of1350℃and holding time of4h.2.Starch can be adopted as a pore-forming agent. When the added amount is10wt.%, the porosity of cordierite is39.48%and the CTE reaches the minimum of1.163×10-6℃-1. But the strength deceases sharply when the amount more than10wt.%.3.The CTE of cordierite decreases and then increases with the increasing of added amount of TiO2. When the addition amount is2wt.%, the CTE reaches the minimum of1.039x10-6℃-1. The addition of TiO2can decreases porosity evidently.4.As the time of acid treatment increases, the CTE of cordierite decreases continuously. Acid treatment can result in pore’s forming and connecting with other. The compressive strength reduces and the grain boundary is corroded.