面向3D打印的连续碳纤维上浆工艺及其对复合材料性能的影响-中国材料进展

文章信息/Info

Title:: Sizing Process of Continuous Carbon Fiber for 3D Printing and Its Influence on the Properties of Composites

Author(s):: ZHANG Manyu; LIU Tengfei; TIAN Xiaoyong; LI Dichen; （School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049, China）

Keywords:: 3D printing; carbon fiber; sizing; interface; mechanical property; composites; Nylon 6 matrix

摘要:: 对连续纤维增强热塑性复合材料（CFRTPCs）进行3D打印能够实现无模具快速制造，扩展增材制造的实际应用。为进一步提高3D打印连续碳纤维增强复合材料制件的性能，采用热塑性上浆剂对干碳纤维进行上浆处理，以尼龙6（PA6）为基体打印连续碳纤维增强复合材料，对比了上浆前后碳纤维表面性质及复合材料力学和界面性能。结果表明，上浆后碳纤维表面极性官能团增加，纤维与树脂浸润性改善；纤维表面粗糙度增加，纤维与树脂的机械结合力增强；上浆后碳纤维增强PA6复合材料较原始碳纤维增强PA6复合材料层间剪切强度提高42.2%，层间结合增强，弯曲强度提高了82%，弯曲模量提高2.46倍；3D打印的上浆后碳纤维增强PA6复合材料试样断面上有明显纤维拔出现象，界面性能显著改善。

Abstract:: Continuous fiber reinforced thermoplastic composites (CFRTPCs) by 3D printing technology can realize the rapid manufacture of complex composite parts without mold and promote the practical application of additive manufacturing. In order to further improve the service performance of 3D printed continuous carbon fiber reinforced composites, this paper adopted thermoplastic sizing agent to size dry carbon fiber, and printed continuous carbon fiber reinforced composites with nylon 6 (PA6) as the matrix, and compared the surface properties of carbon fiber before and after sizing and the mechanical and interface properties of the composites. The results showed that the polar functional groups on the surface of sized carbon fiber increased and the infiltration between fiber and resin improved. The surface roughness increased, and the mechanical adhesion between fiber and resin increased. The interlaminar shear strength of the sized carbon fiber reinforced PA6 composites was 42.2% higher than that of the non-sized carbon fiber reinforced; the interlaminar bonding was enhanced, the bending strength was improved by 82%, and the bending modulus was increased by 2.46 times. By comparing and analyzing the fracture microstructure of 3D printed composites, it is found that the fracture section of the sized carbon fiber reinforced composites had obvious fiber pull out phenomenon, and the interface performance was significantly improved.