The effects of processing parameters on the wedge peel strength of CF/PEEK laminates manufactured using a laser tape placement process

Abstract

Manufacturing thermoplastic composites (TPC) with excellent mechanical properties requires advanced methods with reduced costs and better overall e ciencies. In this study, ber-reinforced thermoplastic polymer composite laminates were manufactured using an automated ber placement (AFP) manufacturing technology. The effects of processing temperature (from 320 ℃ to 500 ℃), lay-up speed (from 20 mm/s to 260 mm/s), consolidation force (from 100 N to 600 N), and prepreg tape tension (from 0 N to 9 N) on the quality of the resulting laminates manufactured using the laser AFP system were investigated. The interlayer bond strength was characterized using wedge peel tests on samples prepared with different process parameters. The studies were complemented by measurements of the thermal properties of the composites using different scanning calorimetry. The optimized process parameter windows were determined to be 360 ℃ to 400 ℃ for the irradiation temperature, 140 mm/s to 160 mm/s for the lay-up speed, 100 N for the consolidation force, and 3 N to 5 N for the prepreg tape tension, respectively. The microscopic analysis of the cross-sections and peel-damaged surfaces revealed that the different distributions of the resin matrix resulting from the different processing parameters affected the interlayer strength. These results may provide an important reference for manufacturing TPC used in aerospace, defense, and automotive applications.

The Effect of Resin Interleafing on the Wedge Peel Strength of CF/PEEK Manufactured by Laser-Assisted In Situ Consolidation

“…According to studies in the literature, higher temperatures, increased pressure, and appropriate fiber tension can yield optimal bonding strength. Based on the author's pre liminary experiments, the optimal layup process parameters were a layup speed of 100 mm/s, a fixed nip temperature of 400 degrees, a layup pressure of 100 N, and a fiber ten sion of 8 N. These process parameters were compatible with the layup equipment in this paper and closely align with the recommendations in the literature [6,9,10,24].…”

“…The wedge peel test has been employed to evaluate the interlaminar properties of samples made by the AFP process [24,27]. The wedge peel test requires a specimen only 4-6 layers thick, while the DCB test requires the thickness to be between 3 and 5 mm, which means 24 to 40 layers, so the specimen preparation and testing of the peel test is more time-saving.…”

Effect of Flashlamp Heating System Parameters on the Wedge Peel Strength of Thermoplastic Carbon Fiber Tape in the Automated Tape Placement Process

“…Stokes-Griffin et al [16] also listed poor fiber-matrix bonding as a possible contributing factor for the failing test. Wedge peel tests have been widely used [13,16,18,59] to compare the interlaminar bonding of different composites and are an alternative to SBS or DCB tests for the evaluation of the bonding strength, as they show good correlation with DCB tests [60]. Although it is not yet standardized for this kind of test, wedge peel testing is conceptually comparable to standardized tests for adhesive bonding, e.g., ASTM D3762.…”

Predicting and Improving Interlaminar Bonding Uniformity during the Robotic Fiber Steering Process

“…Song et al established models for predicting the relationship between the bonding strength between layers in the forming process parameters, and optimized the in situ forming process parameters [ 22 ]. Zhang et al investigated the effects of processing parameters on the interlaminar strength of CF/PEEK laminates, and showed that the main mechanism of mechanical property loss for low melt viscosity matrices in the laminates was due to flow or extrusion of the matrix during processing [ 23 ]. In short, the interlaminar bonding strength can be improved by optimizing the fiber placement process factors, such as compaction force, laying velocity, laying temperature, etc.…”