Mechanisms and orientation dependence of the corrosion of single crystal Cordierite by model diesel particulate ashes

Degradation Resistance of Cordierite Diesel Particulate Filters to Diesel Fuel Ash Deposits

“…For these species to form, aluminum must be extracted from the cordierite with the result that the cordierite–ash interface should become richer in Mg and Si. Maier et al . have observed a similar effect for the interaction of single crystal cordierite with an equimolar mixture of Mg, Ca, and Zn phosphates.…”

“…However, the enrichment of Mg and Si in the corrosion product may reduce liquidus temperatures to facilitate this as the process goes on. Given the findings reported herein and those reported by Maier et al ., it is clear that cordierite degradation to form a ZnAl 2 O 4 spinel is due to solution by phosphate‐based liquids. The gettering of phosphorus from the ash system by ceria, as discussed above, reduces the probability of liquid phase formation and this is why the zinc aluminate spinel occurs in less significant amounts in the X‐ray phase assemblage.…”

“…While the above chemical durability experiments were of benefit in assessing the durability of cordierite to potential diesel ash impurities, lead and sodium impurity levels in diesel fuels are miniscule (typically 2 ppm for sodium, although sodium levels may increase as Biodiesel becomes more commonly used) . O'Sullivan et al .…”

“…Results showed again that only sodium and lead oxides induced significant chemical interaction by the formation of sodium and lead zirconates. Maeir et al 13 have investigated the chemical interaction between single crystal cordierite and a soda-silica mixture of composition Na 4 Si 3 O 8 with a lowest liquidus of 830°C. As might be expected, the cordierite reacted rapidly with the liquid alkali-silicate at temperatures of 900°C and 1000°C allowing cordierite dissolution.…”

Processing and properties of pressable ceramic with non-uniform reinforcement for selective-toughening

“…A strong interface between brittle ceramic-matrix and ductile metal reinforcements is essential for nearly all ceramic/metal composites [1][2][3][4][5][6][7][8][9][10], particularly if strength improvement is required besides toughness enhancement. A weak ceramic/metal interface is conditionally desirable for the pull-out and frictionalsliding toughening mechanisms, important to crack-bridging [11,12], but should generally be avoided if long-term reliability, environmental influence, surface contact and wear resistance, important to many bio-materials and industrial applications, are key concerns to the design and processing of a metal reinforced ceramic-matrix composite.…”