Continuous carbon fiber-reinforced PEEK composites were 3D printed using DED process. Optical and electron microscope image of the printed samples show low levels of void content. Tensile strength and modulus of the printed composites at 0/90 degrees are 653 MPa and 60 GPa. respectively. TGA results show that the printed composites have high char yield of 81.9 wt.% at 1.000°C. From the MCC data, the PEEK/cCF composite exhibits greatly enhanced flame-resistant properties which is a good indication for the ablation testing. Experimental results from the OTB aerothermal ablation tests show that the PEEK/cCF composites have high mass retention at various heat flux and durations. The low backside temperature also indicates that the PEEK/cCF composites are highly thermally insulative in the through-thickness direction. However, char expansion and first layer delamination occurred at all test conditions. Morphology analysis on the char layer show a skeleton of carbon fibers with majority of the PEEK polymers decomposed.
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