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A novel ceramic-metal composite with continuous interconnected ceramic and metal phases has been fabricated from sintered porous particulate AlN preforms infiltrated with magnesium. The 48 vol. % AlN composites are fabricated by pressureless infiltration in argon in the temperature range of 870 °C to 960 °C. An increase in the infiltration rate is observed as the temperature increases. Results on the mechanical characterization of the composites indicate an elastic modulus of 90 to 110 GPa and hardness of 70 to 80 HRB. The tensile strength calculated by the shear punch test method ranges from 260 to 390 MPa. As a general rule, it is observed that the lower the infiltration temperature, the higher the tensile strength. The linear coefficient of thermal expansion of the infiltrated composites in the temperature range of 215 to 315 °C is 7.65 x 10-6 °C-1. This value is lower than those found for similar Al/AlN composites reported in the literature.

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Amorphous fibres of the Alsystem were prepared by a melt extraction technique, and subjected to crystallisation. T he quality of the melt extracted fibres is controlled by the wheel edge and rotational speed, with both having a significant eVect on fibre diameter and avoidance of irregularities and instabilities along the fibre length. T ensile strength in the glassy state varied from 0•6 to 1•0 GPa. Crystallisation activation energies calculated f rom scan-rate dependence of DTA peaks are 741 and 1374 kJ mol−1 for E1 (Al 2 O 3 -yttrium aluminium garnet (YAG) eutectic), 390 kJ mol−1 for YAG, and 438 kJ mol−1 for E2 (YAG-yttrium aluminium perovskite (YAP) eutectic) by the Kissinger method; and 698 and 1346 kJ mol−1 for E1, 352 kJ mol−1 for YAG, and 399 kJ mol−1 for E2 by the Augis-Bennett method.BCT /438

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