Abstract: Fabrication apparatus is described for improving the ultimate strength of boron and other high strength filaments. In the apparatus, a gradual cooling zone is placed at the exit end of the reaction zone to prevent the sudden thermal shock normally encountered when hot boron filaments exit into the ambient atmosphere. A preheating zone can be added prior to the entrance into the reaction zone if desired. Additionally, the entrance and exit ends of the reaction zone are sealed with a molten metal, such as tin, heated to elevated temperatures close to the reaction temperature. These molten metal electrodes tend to minimize deposition of weak boron due to a low temperature region immediately following the reactor entrance and help to eliminate sudden thermal shocks to the filaments at the exit.

Abstract: A vacuum bag autoclave type procedure for curing layers of phenolic resin pregnated fibrous material to form a composite structural part. A straight up heat rise cure cycle is employed in conjunction with a layup and bagging procedure that ensures a relatively free bleed of excess resin during cure and a high-capacity vacuum system for removal of volatiles generated during cure. This method of fabrication releases the majority of volatiles prior to gelation and produces a part having a pore structure that provides an escape path for gases generated during cure and postcure to prevent delamination.