Abstract

The miniature ultrasonic sensor is specially developed for the on-line cure monitoring the matrix of organic composites. The dimensions of sensor can be small enough (diameter 0,3 mm, length 3 mm) that will be possible it embed into composite structure during its processing. Acquired data characterise various curing stages that occur during the polymerisation: increasing of viscosity, gelation and consolidation. Making the sensors of different resonant frequency (1... 2 MHz) it is not complicated they connect into one diagnostic line in odder to control more points of thermosets of interest.

Isothermal curing at 65°C and 0.484 MPa pressure with marked characteristic stages:
A - heating and softening;
B - increasing viscosity due to onset of chain extension;
C - onset of crosslinking with cure rate increasing;
D - consolidation with cure rate degreasing.