Thermal Aging Behavior of SiC Substrate in the Presence of Ash Materials and Alkali Metals

The objective of the study is to clarify the effect of ash materials and alkali metals deposition on SiC-DPF substrate damage with high temperatures on simulated uncontrolled regeneration. The ash materials are selected from engine oil compounds. The alkali metals using for additive catalysts are also examined on the reaction at high temperature. The ash materials used in the experiment were CaCO₃, Fe₂O₃, MgO and SrCO₃ to the substance, and the reaction temperature between SiC and the ash materials were observed. The effects of alkali metals (such as Na, K and Cs) on the substrate damage were observed. Additionally the mixture of the alkali metals and the ash materials were examined. The results were observed by the naked eye, SEM, and XRD. When the individual ash material exists on the surface alone, the SiC surface did not change at a temperature of 1300°C. However, in the presence of ash materials together on the SiC surface, the SiC substrate melting temperature dropped to 1020°C. In the case of alkali metals, Cs shows moderate staining at 1200°C. However when the alkali metals are mixed together, the reaction between the alkali metals and the SiC started from 900°C. The melting temperature of SiC with mixture of all kinds of the ash materials and the alkali metals was observed at 800°C.