Processability and reusability of CF/PEEK mixture for Powder Bed Fusion of high strength composites

As an Additive Manufacturing (AM) technology, Powder Bed Fusion (PBF) of Polyether-ether -ketone (PEEK) with high strength had a great potential in many fields. However, the very high preheating temperature in the printing process, shrinkage and warpage of parts, poor reusability of powder limited the industry opportunities. Concurrently, carbon fiber (CF) was added in the PEEK powder to prepare higher strength composites, and yet the processability of the powder was seldom discussed, which was very crucial for the industry application. In this paper, the processability of CF/PEEK mixture powder was focused. The results showed the preheating efficiency of mixture powder was highly enhanced, and the preheating temperature could be lower (305 °C) than pure PEEK (>320 °C), which decreased the process difficulty. Meanwhile, the sintered CF/PEEK composite parts had much smaller shrinkage and warpage, thereby improving the accuracy of the parts significantly. Beyond that, the CF/PEEK mixture showed a better reusability compared with PEEK. For the CF/PEEK mixture, the strength of composite built with the fourth recycled powder showed a slight decrease comparing with the virgin powder. While, the strength of pure PEEK part built with the second recycled powder began declining sharply. Therefore, the enhanced processability and better reusability of CF/PEEK mixture powder manifested the significant potentiality in the industry.