Graphite-PEEK

Bucher, R.A, and Hinkley, J.A. (1992). Fiber/matrix adhesion in graphite/peek composites. J. Thermoplastic Composite Mater. 5, 2-13. 

The Li-Loos intimate contact model was verified for compression molded unidirectional graphite-polysulfone and graphite-PEEK (APC-2) laminae and graphite-PEEK (APC-2) cross-ply laminates. The degrees of intimate contact of the unidirectional and cross-ply specimens were measured by optical microscopy and scanning acoustic microscopy, respectively. The predicted degrees of intimate contact agreed well with the measured values for both the unidirectional and cross-ply specimens processed at different temperature and pressures. 

In the following example, scanning acoustic microscopy is combined with optical microscopy to measure intimate contact at the ply interfaces of a [0o/90o/0°]r graphite-PEEK laminate. First, eight holes, 1.5 mm (0.059 in.) in diameter, were drilled into the composite specimen. These holes, shown in Figure 7.12, were used to locate where on the composite specimen the scanning acoustic microscope images were taken. 

For TP tapes, a TP welding head has been developed, in conjunction with a hot gas torch. This uses the latter as a heat source to melt the prepreg tow prior to lying down and consolidation with the pressure roller. It does not rely on tension and can therefore be used for concave surfaces. Winding speeds of more than 0.15 m (6 in.)/s has been achieved with graphite/PEEK prepregs. 

As you can see, bone is a very complex composite material and, as snch, is difficult to artificially replicate. Nonetheless, there are a nnmber of materials of all types that are being nsed as bone replacements. Polymethylmethacrylate (PMMA), titaninm, graphite/polyethyletherketone (PEEK) composites, and tricalcinm phosphate, among... 

Yoon TH, McGrath JE (1992) Enhanced adhesive performance of thermoplastic po-ly(imide siloxane) segmented copolymer with peek-graphite composites by gas plasma treatment. High Perform Polym 4(4) 203... 

Yoon TH (1991)AdhesionstudyofthermoplasticpolyimidesandTi-6Ai-4v allow and peek-graphite composites. PhD thesis, Virginia Polytechnic Institute and State University, Blacksburg... 

Yoon TH, McGrath JE (1991) Effect of surface preparation and thermoplastic ahesive structure on the adhesion behavior of peek-graphite composites. Mater Res Soc Symp Proc 190 (Plasma Process Synth Mater) 3 137-142... 

Gruman has developed an automated triangular truss-type beam builder using graphite-reinforced polyether sulfone. This beam can be formed in outerspace at the rate of 1.5m per min. from flat stock which is heated and forced continuously around a die. The sections are Induction welded and may be protected from deterioration by the application of a coating of polyether ether ketone (PEEK).(30)... 

RTP produces series of engineering thermoplastics lubricated with PTFE, molybdenum disulfide, graphite powder, silicone and glass, carbon and aramid fibers. Grades AR, TEE and SI include respectively aramid fibers, PTFE (10-20%) and silicone fluid (0.5%). Matrix materials used include PA-6, PA-66, PA-6,10, PA-12, PC, POM, PET, PBT, PSF, PPS, PEI, PEEK and polyphthalamide. The blends have been developed for injection molding of various parts for engineering applications. 

Besides graphite, carbon and glass fibers, organic fibers, e.g., Kevlar, have also been used to reinforce thermosetting resins, e.g., epoxy resin (38). One of the newest developments is fiber-reinforced thermoplastics, e.g., carbon fiber-reinforced polyether ether ketone (PEEK) ( ). These materials are rather tough as demonstrated in the interlaminar toughness values (Table... 

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