Fabrication and application of co-continuous Al2O3/Al composite by reactive infiltration of molten Al into the preform of SiO2 with cordierite addition

Abstract

Abstract Interpenetration Al2O3/Al(Si) composites were fabricated by reactive infiltration of molten Al into the preforms with SiO2–4.6 mol.% cordierite at 1150 °C in air. The formation kinetics and microstructures of the composites were investigated. Experimental results show that the addition of cordierite in SiO2 is favorable for wetting of molten Al on the preform, leading to high growth rate of the composite (8.76 mm min –1). The growth rate of the composite was controlled by the infiltration of molten Al into the preform through the open pores and cracks formed during the preform fabrication or through microcracks created during the infiltration process. Since the addition of cordierite in SiO2 can lower the preform sintering temperature, one of its applications is used for ceramic – ceramic or ceramic – metal joints. A strong Al2O3–Al2O3 joint with a shear strength of 109 MPa was fabricated and investigated using the Al2O3/Al(Si) interlayer formed by this method.