Another Breakthrough In Continuous Fiber Reinforced Composites: CCF / PEEK 3D Printing Explores The Manufacturing Prospect Of High-Performance Composite Structures

  As a high melting point semi crystalline engineering plastic, Peek (polyether ether ketone) has attracted attention and research in various application fields such as aviation, aerospace, automotive industry and medical treatment because of its good thermal stability, corrosion resistance, excellent mechanical properties and biological compatibility.

  Continuous Carbon Fiber Reinforced PEEK (CCF / PEEK) composites have been used in aerospace and other fields in the 20th century. However, due to the manufacturing method, the parts with complex structure can not be obtained in this way, which has also become a crucial problem restricting the application of CCF / PEEK composites.

  Researchers of Xi'an Jiaotong University took advantage of the technical advantages of continuous fiber reinforced thermoplastic resin matrix composite additive manufacturing equipment to promote the manufacturing of CCF / PEEK composite additives. As shown in Figure 1, the researchers used the combo-i printer to introduce the laser real-time auxiliary heat treatment process, and combined with the fiber pre impregnation process to effectively improve the z-direction performance in printing, so as to improve the overall mechanical properties of the parts.

Fig. 1 printing and testing process of CCF / PEEK Composite

  It is found that, as shown in Figure 2, before the implementation of laser real-time heat treatment, the introduction of continuous fiber is very easy to form a multi-scale weak bonding interface inside the workpiece, while the introduction of laser and pre impregnation technology can greatly improve various internal weak bonding, so as to avoid premature failure and poor mechanical properties, The interlaminar shear properties and tensile properties reached 35MPa and 480mpa respectively. Not only for CCF / PEEK composites, researchers have found that for the melting deposition 3D printing process of pure peek materials, laser preheating is of great benefit to the performance improvement of parts, and the interlaminar shear performance is improved by 45%. By rapidly absorbing and heating the laser locally by the material, on the one hand, the large-area volume shrinkage is avoided, and at the same time, its sufficient crystallization is ensured, so as to greatly improve the modulus, mechanical properties and thermal stability of the parts.

Fig. 2 Comparison of performance improvement

  This project is supported by the national key R & D Program - Research on manufacturing mechanism of continuous fiber reinforced composites (2017YFB1103401).