Processing of PAEK-graphite fabric composites – Pros and cons of film technique over powder sprinkling technique

Abstract

Fabric-(BD-bi-directionally) reinforced high performance polymer composites are well-known for their exceptional mechanical, thermal and tribological properties. However, their processing is generally challenging, especially for specialty polymers like Polyetheretherketone (PEEK), Polyaryletherketone (PAEK) etc. mainly because of unavailability of a right kind of solvent which restricts exploitation of solution impregnation technique. Having very high melting points along with high melt-viscosity and high oxidation tendency, the possibility of melt-impregnation also gets eliminated. Furthermore, unavailability in fibrous form restricts the processing possibility by commingling technique. The possible options left for developing such composites perhaps are by film-stacking and powder-sprinkling techniques although the major issue of non-wetting at cross-over points remains unaddressed. This paper reports on the maiden effort on developing, characterizing and in depth performance analysis of graphite fabric reinforced PAEK composites. Powder-sprinkling and film-stacking techniques were employed in this work by maintaining identical processing parameters and fabric amount. The comparative performance evaluation led to a conclusion that film-stacking technique excelled in almost all performance properties barring thermal conductivity and thermo-mechanical performance. The performance analysis was based on various techniques such as thermal-conductivity, field emission scanning electron microscopy (FESEM) on polished cross-sections, thermal and thermo-mechanical analysis, mechanical testing, micro-computed tomography, abrasive wear studies etc.