Available at: http://digitalcommons.calpoly.edu/theses/1224
Date of Award
MS in Engineering - Materials Engineering
As applications for thermoplastic composites increase, the understanding of their properties become more important. Fabrication methods for thermoplastic composites continually improve to match designs specifications. These advanced thermoplastics have begun to show an improvement in mechanical properties over those found in thermoset composites commonly used in industry. Polyaryletherketones (PEK) have high service temperatures, good mechanical properties, and improved processing capabilities compared to thermoplastics used in the past making them important to the aerospace industry. The wide range of types of PEK make them suitable for a variety of applications, but selection of specific chemistries, processing parameters, and composite stack-ups determine the mechanical properties produced. Differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR) were used to determine crystallinity and chemical properties of several polyaryletherketones. Tensile, compressive, and Mode I interlaminar fracture toughness tests were conducted to analyze mechanical properties of these advanced thermoplastics. Several fabrication processes were also tested to determine optimal consolidation and aesthetic appearance of structural members. All testing was conducted at The Boeing Company in Seattle, Washington. Because all testing and conclusions are proprietary a general synopsis of the experience will be presented.