Strengthening and toughening of cordierite by the addition of silicon carbide whiskers, platelets and particles

Abstract

Cordierite containing silicon carbide of different morphologies has been fabricated to produce composites with superior properties to the unreinforced cordierite. It has been demonstrated that the morphology of the silicon carbide affects the densification and the mechanical properties of the composites they constitute. The densification process was controlled by the degree of mutual contact of the silicon carbide phase within the cordierite matrix and by the rigidity of the resulting networks. The operative toughening mechanisms and their relative contributions were also dependent on the morphology of the silicon carbide. Fracture strength of the composites was governed by the relative contributions of an improvement in fracture toughness and by the magnitude of the critical flaw size.

Characterisation of borosilicate glass matrix composites reinforced with SiC or ZrO2

“…33 SiC whiskers have been widely used to reinforce glass ceramics, resulting in composites with excellent properties. 21 Figure 8 shows the cold crushing strength of composite samples sintered at 875uC as a function of SiC content.…”

Fabrication of Nitrogen‐Containing Cordierite Ceramics

“…Therefore, several researches have focused on improving the mechanical properties of a-cordierite ceramics through the dispersion of a secondary phase such as SiC, ZrO 2 , or mullite in a cordierite matrix. [10][11][12][13][14][15][16] After oxynitride glass was developed in the mid-1960s, 17 considerable research has been carried out on oxynitride glass fabrication, revealing that nitrogen incorporation into the oxide glass network enhances the mechanical and chemical properties of oxide glasses significantly. 18 These changes in the properties have been explained on the basis of the Mulfinger model, 17 in which the glass structure of silicate becomes dense because of the presence of three Si(O,N) 4 structural units in the local region around an N atom, and the structure is strengthened on average because of the existence of three bonds per N atom as a substitute for the two bonds of the O atom.…”

Toughening of Glass by a Piezoelectric Secondary Phase

“…N UMEROUS studies exist that describe the many mechanisms leading to toughening and strengthening in glass-matrix and glass-ceramic-matrix composites, which include, for example, crack bowing, crack deflection, load transfer, residual internal stresses, inclusion (fiber) pullout, interface debonding, crack bridging, and inclusion plastic deformation. [1][2][3][4][5] Usually, the toughening and strengthening achieved by the incorporation of long fibers is much greater and impressive than that achieved by a dispersion reinforcement, e.g., addition of a discontinuous particulate phase. 1 However, composites that consist of particulate reinforcement are easier to produce than fiber-reinforced composites and their fabrication involves cost-effective and simple powder technology techniques.…”