THERMALLY-INDUCED DELAMINATION OF MULTILAYERS

Steady-state delamination of multilayered structures, caused by stress es arising during processing due to thermal expansion mismatch, is ana lyzed by a fracture mechanics model based on laminate theory. It is fo und that inserting just a few interlayers with intermediate thermal ex pansion coefficients may be an effective way of reducing the delaminat ion energy release rate. Uneven layer thickness and increasing elastic mismatch are shown to raise the energy release rate. Experimental wor k confirms important trends of the model. (C) Acta Metallurgica Inc.