Characterization by acoustic microscopy of adhesion in poly ethylene terephtalate/films coated by aluminium

The adhesion of aluminium deposits on poly ethylene terephtalate. PET. films is studied by acoustic microscopy. The contrasts observed on the acoustic images recorded in different conditions of focusing are consistent with unbonds. The comparison of experimental acoustic signatures V z. with acoustic signatures modelling different types of contacts and of lacks of adhesion explains the defects by adhesion losses and corroborates the observations by imaging. The cohesion between the PET matrix and the other phases, ceramic grains and cyclic oligomers, is discussed. q1998 Elsevier Science B.V