IMPROVED LAMINATE PHYSICAL AND MECHANICAL PROPERTIES USING 'HY-TEST' VACUUM ASSISTED RESIN TRANSFER MOLDING

摘要

The Composite Affordability Initiative (CAI) program has shown that the economical insertion of composite materials in aerospace structural applications is enhanced by the use of integrated structures. A growing number of vacuum assisted resin infusion process methods are being used or developed for the purpose of achieving low cost high performance composite hardware. Originally derived from the boating industry, this Vacuum Assisted Resin Transfer Molding (VARTM) process has been used in recent years to demonstrate the potential manufacturing capability for a variety of composite hardware in the aerospace industry. A known deficiency amongst conventional VARTM methods has been inconsistent laminate thickness and fiber volume fraction. Fiber volume fraction using conventional VARTM processes is generally reported in the 40-55 percent range and below the 57-62 percent range needed for high specific strength and ultimate tensile and compressive properties. This paper compares the conventional VARTM processes and an improved process dubbed "Hy-Test." The process modifications necessary for these improvements and the resulting physical and mechanical properties are discussed. The physical properties include cured resin content and fiber volume fraction. Topographic maps of cured unidirectional and cross ply laminates are presented demonstrating thickness uniformity resulting from the improved process when applied in both vertical and horizontal infusions.