Method for Out-of-autoclave Fabrication of High Fiber Volume Fraction Fiber Reinforced Polymer Composites.

摘要

The U.S. Army Research Laboratory (ARL) has a long history in the fabrication of composite materials for both lightweight structures and vehicular armor. Through the years, ARL research has focused on cost-efficient materials and processes with Army-specific goals in mind. While retaining the Army perspective, we are focusing on basic scientific fundamentals that lead to high quality, cost-effective composite systems for uses across the scientific spectrum. In our research, we have been increasing the fiber-volume fraction by vacuum-assisted resin transfer molding (VARTM) in order to produce composite structures with aerospace-grade qualities. Of specific focus is the control of processing parameters during resin infusion to obtain fiber-volume fractions like those of autoclave-processed composites. Using a combination of viscosity control, ARL-based VARTM techniques, and a pressure control system, we increased the fiber-volume content from 50% (ARL s normal processing range for a particular material system and VARTM process) to over 60%. Future work will focus on achieving a 65% fiber-volume fraction with this material system. This jump in fiber-volume fraction can provide higher strength-to-weight ratios in composite parts while cutting the fabrication cost. As a result, we are well on the way to providing cost-effective advanced composite materials. Processing characteristics are presented and evaluations are discussed.