ANALYSIS OF METAL-CERAMIC BONDING BY FRETTAGE

Metal-ceramic bonds have been produced by sintering a metallic hollow cold-pressed cylinder (iron-based powder) around a ceramic insert (silicon nitride). Pushout tests were carried out to characterize the bond strength. An analytical model considering a strain-hardening plastic matrix was developed and used to analyze the pushout tests in terms of residual stresses. Dilatometry and tensile tests were also carried out on the matrix materials in order to characterize phase transformations and mechanical behavior. These data are then used in the model to calculate a friction coefficient between the steel and the ceramic at different temperatures. The validity of the model is checked by comparing measured and calculated hoop deformations of the metal ring during pushout.