Fracture of silicon nitride joined with an aluminium braze

Mechanical Properties of silicon nitride joined with aluminium braze have been investigated using fracture mechanics. The highest bonding temperature, 1133 K, produced the highest four-point bend strength of 417 MPa, the strength depending strongly on stress rate. The fracture parameter,N, for slow crack growth in the joint was 29.7 which was near to that of the silicon nitride. Stress corrosion cracking is believed to be one of the serious problems associated with ceramic joining.