短-连续碳纤维同步增强热塑性复合材料预浸线材制备及3D打印工艺分析  

Short-continuous Carbon Fiber Synchronous Reinforced Thermoplastic Composites:An Analysis on the Manufacturing and 3D Printing Process of Its Prepreg Filament

作　　者：王福吉[1,2] 王公硕 王洪全 付饶[1,2] 吴博[2] 王琦[1,2] WANG Fuji;WANG Gongshuo;WANG Hongquan;FU Rao;WU BoWANG Qi(State Key Laboratory of High-performance Precision Manufacturing,Dalian University of Technology,Dalian 116024;Key Laboratory of High-performance Manufacturing for Advanced Composite Materials,Dalian University of Technology,Dalian 116024)

机构地区：[1]大连理工大学高性能精密制造全国重点实验室,大连116024 [2]大连理工大学辽宁省先进复合材料高性能制造重点实验室,大连116024

出　　处：《机械工程学报》2024年第11期283-295,共13页Journal of Mechanical Engineering

基　　金：国家自然科学基金重点(52130506,52090053);大连市顶尖及领军人才(2021RD08)资助项目。

摘　　要：碳纤维增强热塑性复合材料3D打印技术,是实现先进复合材料复杂结构件一体化制造的有效途径。由于短纤维不连续、连续纤维间基体的载荷传递能力弱,3D打印短或连续碳纤维等单一形态纤维增强热塑性复合材料的力学性能提升进入瓶颈期。发展短-连续碳纤维同步增强热塑性复合材料(Short-continuous carbon fiber synchronous reinforced thermoplastic composites,S/C-CFRTP)3D打印技术,是突破复合材料复杂结构件高质量制造技术瓶颈的重要途径。然而,由于含短纤维的基体熔融黏度大、3D打印温压时变性强,现有原位浸渍工艺难以保证基体对连续纤维的充分浸渍,导致3D打印S/C-CFRTP力学性能较差,无法满足工程应用需求。提高纤维-基体浸渍程度是实现S/C-CFRTP高质量3D打印的关键。基于离线浸渍方法,提出同步增强预浸线材制备及3D打印工艺。研究了同步增强预浸线材制备工艺路线、参数对其浸渍程度、纤维含量及抗拉强度的影响,提出了“混合-浸渍-定形”工艺路线、“小制丝速度-大出口直径”工艺参数的预浸线材高质量制造策略,其抗拉强度达448.70 MPa。同时,通过对比不同打印工艺成形样件的空隙、纤维含量和抗拉性能,发现预浸线材挤出工艺将S/C-CFRTP的空隙率降低近一半,纤维含量提高约7%,抗拉强度和模量提升约18.6%和11.6%,达约430.45 MPa和38.51 GPa。The 3D printing technology of carbon fiber reinforced thermoplastic composites is an effective way to realize the integrated manufacturing of advanced composite parts with complex structures.Due to the discontinuity of short fiber and the weak load transfer capability of the matrix between continuous fibers,the mechanical property enhancement of 3D printed single-form(short or continuous)fiber reinforced thermoplastic composites has entered a bottleneck period.In order to break through the technical bottleneck of high-quality manufacturing for advanced composite parts with complex structures,it is vital to develop the short-continuous carbon fiber synchronous reinforced thermoplastic composites(S/C-CFRTP)3D printing technology.However,due to the high melt viscosity of the matrix containing short fiber and the rapidly changing temperature-pressure of the deposition material,it is difficult to make a full impregnation between continuous carbon fiber and matrix during the in-situ impregnation 3D printing process.Poor impregnation results in the weak mechanical properties of S/C-CFRTP parts,which can not meet application requirements.Improving the fiber-matrix impregnation percentage is the key to achieving high-quality 3D printing of S/C-CFRTP.Based on the offline impregnation method,the manufacturing process and 3D printing process of S/C-CFRTP prepreg filament are proposed.The influence of prepreg filament manufacturing process route and process parameters on its impregnation percentage,fiber content,and tensile strength were studied.A high-quality manufacturing strategy with a“mixing-impregnation-shaping”process route and“low filament-making speed and large outlet diameter”process parameters is proposed.The maximum tensile strength of prepreg filament reached about 448.70 MPa.Meanwhile,comparing the S/C-CFRTP parts printed by different printing processes,it is found that the towpreg extrusion printing process reduced the void fraction by nearly half and increased the fiber content by about 7%.The tensile

关 键 词：短-连续碳纤维同步增强热塑性复合材料 预浸线材 3D打印 浸渍程度 抗拉性能 

分 类 号：TH16[机械工程—机械制造及自动化] TB33[一般工业技术—材料科学与工程]