Reaction hot-pressing and property-composition relationships of modified sialon - boron nitride hetero-modulus ceramics

Hetero-modulus ceramics (HMC) present the combination of a ceramic matrix with inclusions of a dispersed phase with considerably lower values of Young's modulus, resulting in a material with significantly advanced properties. Densified '-Si6-xAlxOxN8-x based HMC materials, with various volume contents of low-modulus alpha-BN phase and modifiers such as TiN or ZrO2 in sialon matrix, were prepared by high-temperature reaction hot-pressing in nitrogen atmosphere. The pristine blend composition for reaction hot-pressing consisted of mixed fine powders of Si, Al, B, Ti nitrides and Al, Zr oxides. Statistical design of 2(5-2) fractional factorial and third-order simplex-grid types was used for the experimental studies to estimate the effects of some technological factors on the densification of hot-pressed products and the property-composition relationships of modified HMC materials.