M. Bersani et al., INTERACTIONS BETWEEN LEAD-OXIDE AND CERAMIC SUBSTRATES FOR THICK-FILMTECHNOLOGY, Journal of materials research, 12(2), 1997, pp. 501-508
This paper deals with the mechanisms and kinetics of interactions betw
een screen printed and fired PbO layers and ceramic substrates: alumin
a and beryllia. The interaction with alumina occurs via two main proce
sses: (i) a reaction between PbO and Al2O3 grains, which induces the f
ormation of a crystalline phase, Pb2Al2O5; and (ii) an interdiffusion
process involving Pb and the intergranular amorphous phase in the cera
mic substrate. This latter process results in a compositional change o
f the intergranular phase at considerable depths inside the ceramic su
bstrate, as well as in the formation of a high lead glass layer on the
substrate surface, Since PbO is not completely reacted, the Pb penetr
ation in the ceramic is diffusion limited (penetration depth w approxi
mate to t(d)(1/2) where t(d) is the reaction time) with an activation
energy of 1.20 +/- 0.05 eV. The ceramic microstructure significantly a
ffects the interaction processes.