Influence of Interlayer's Thickness on Strength of Joints between LAS Glass-ceramic and Carbon/Carbon Composites

Surface modified carbon/carbon (C/C) composites were joined to Li2CO3-Al2O3-SiO2 (LAS) glass ceramic by hot pressing bonding using MgO-Al2O3-SiO2 (MAS) glass with different thicknesses as the joining material. The effect of interlayer thickness on the joint strength was discussed. Microstructures and morphologies of the as-received joints and fractured surfaces were characterized by scanning electron microscope. The results indicated that the LAS glass was directly joined to the surface modified C/C composites at 1200 degrees C, and the room-temperature shear strength of the joints was only 10MPa, due to its poor wettability with base material. When the MAS glass was applied as interlayer, the joint shear strength increased at first and then decreased with the increase of the interlayer thickness. The maximum value of the shear strength reached 26.61MPa when interlayer thickness was 80 mu m.