Effect of Fiber Type and Content on Mechanical Property and Lapping Machinability of Fiber-Reinforced Polyetheretherketone

Abstract

Polyetheretherketone (PEEK) is a novel polymer material with excellent material properties. The hardness and strength of PEEK can be further improved by introducing fiber reinforcements to meet the high-performance index of the aerospace industry. The machinability will be influenced when the material properties change. Therefore, it is crucial to investigate the influence of material properties of the fiber-reinforced PEEK on machinability. In this paper, the main materials include pure PEEK, short carbon-fiber-reinforced PEEK (CF/PEEK), and short glass-fiber-reinforced PEEK (GF/PEEK). The effects of the fiber type and mass fraction on the tensile strength, hardness, and elastic modulus of materials were discussed using the tensile test and nanoindentation experiments. Furthermore, the fiber-reinforced PEEK lapping machinability was investigated using lapping experiments with abrasive papers of different mesh sizes. The results showed that the hardness and elastic modulus of PEEK could be improved with fiber mass fraction, and the tensile strength of CF/PEEK can be improved compared with that of GF/PEEK. In terms of lapping ability, the material removal rates of the fiber-reinforced materials were found to be lower than the pure PEEK due to the higher hardness of the fiber. During the lapping process, the material removal methods mainly included the ductile deformation or desquamation of reinforcing fiber and ductile removal of the PEEK matrix. The lapped surface roughness of PEEK material can be improved by fiber reinforcement.

Effect of Fiber Type and Content on Surface Quality and Removal Mechanism of Fiber-Reinforced Polyetheretherketone in Ultra-Precision Grinding

“…Therefore, adding carbon fibers could effectively reduce the degree of material swelling on both sides of the PEEK matrix grooves and improve the grinding surface quality. On the other hand, the CF30/PEEK’s nano-indentation curve was higher than CF10/PEEK [ 21 ], indicating that CF30/PEEK had a better deformation resistance. As seen in Figure 7 and Figure 8 , the grooves on the surface of CF30/PEEK were shallower than those on CF10/PEEK after grinding with the same grit size grinding wheel.…”

“…However, both CF30/PEEK and GF30/PEEK were weak plastic materials. Thus, based on the tensile test results of Gao et al [ 21 ], this paper sorted the minimum cutting thickness values of different materials by calculating the ratio of the elastic modulus to tensile strength and divided the value of k into five different values corresponding to five different materials in the test. Table 6 shows the value results.…”

“…Because the surface quality of PEEK and fiber-reinforced PEEK is temperature sensitive, the surface roughness of each material tends to decrease first and then increase with the increase in cutting speed. Gao et al [ 21 ] studied the lapping performance of PEEK, carbon-fiber-reinforced PEEK and glass-fiber-reinforced PEEK. The results showed that the surface roughness and material removal rate of fiber-reinforced PEEK were lower than those of pure PEEK under the same grinding parameters.…”