Thermally compensated clamps - for carbonation of carbon fibre or graphitic laminates, to prevent overstressing of clamping plates

摘要

A jig for clamping together a composite structure involving carbon fibres or compacted graphite prior to hot deposition of carbon from a vapour phase (i.e. CH4 at 1100 degrees C), comprises spacers made of a thickness and composition which compensates for thermal expansion and contraction parallel to the clamping length of the main jig components during the thermal cycle. The sepn. distance of the clamping plates may be maintained constant or allowed to contract or dilate by a small and controlled amt. during the thermal cycle. Exposure and coating of the core faces and consequent distortion or cracking of the (carbon) clamping plates on cooling about an over-size core is thus avoided.