T700/PEEK热塑性自动铺放预浸纱制备质量控制及性能研究

Quality control and mechanical properties of T700/PEEK thermoplastic prepreg for AFP

为满足高性能热塑性复合材料自动铺丝(AFP)成型工艺的原材料需求,研究了粉末悬浮法浸渍制备T700/PEEK预浸纱关键工艺参数及预浸料性能,分析聚醚醚酮PEEK浸渍连续碳纤维过程中不同工艺参数(悬浊液浓度、超声功率、张力、牵引速率、浸渍温度、辊压温度及压辊间隙)对预浸纱质量的影响规律,利用扫描电子显微镜(SEM)观察T700/PEEK预浸纱内部孔隙率及界面结合状态,将粉末悬浮法制备的T700/PEEK预浸纱模压制备了热塑性复合材料单向层合板试样,并测试了其热塑性复合材料层间剪切强度和拉伸强度。研究结果表明:预浸纱含胶量与粉末悬浮液浓度变化线性正相关,且随超声功率的增大而升高;浸渍过程中伴随温度的升高以及牵引速率的减小,预浸纱宽度变小、孔隙率降低,随着张力的增大,预浸纱宽度增大、孔隙率降低;辊压成型过程中随着温度的提高以及压辊间隙的减小,预浸纱宽度增大、孔隙率降低。综合考虑各工艺参数的影响规律,获得优化的热塑性预浸纱制备工艺参数:浸渍温度为360~370℃,辊压温度为330℃,压辊间隙为0.1mm,牵引速率为15~20mm/s,张力为7N。扫描电镜结果显示树脂与纤维界面结合紧密,复合材料的孔隙率可降低至1.8%,复合材料层间剪切强度为73.43 MPa,纵向拉伸强度达1.71GPa。

To meet the demand for high performance thermoplastic composites applied to Automated Fiber Placement（AFP）technology,the key technological parameters and mechanical properties of T700 carbon fiber reinforced PEEK（Polyetheretherketone）prepreg manufactured by the slurry method were studied.The influences of different technological parameters（slurry concentration,ultrasonic power,tension,pulling speed,impregnation temperature,rolling temperature,and roller gap）on the quality of the prepreg in the process of continuous carbon fiber impregnated by PEEK were analyzed,and the Scanning Electron Microscope（SEM）was used to verify the porosity and observe the interface morphology of T700/PEEK prepreg.Interlaminar shear strength and tensile strength of the unidirectional composite laminate molded by T700/PEEK prepreg was also tested.The results show that resin content was in linear positive correlation with slurry concentration,and increased with magnifying ultra-sonic power.In the impregnation process,the width and porosity of prepreg decreased with the increase of temperature increment and pulling speed,and as the tension increased,the width of prepreg increased,but the porosity decreased.In the rolling process,with the increase of the temperature and the decrease of the roller gap,the width of prepreg increased and the porosity decreased.The processing parameters were all taken into consideration to obtain the optimum parameters as follows：impregnation temperature 360-370℃,rolling temperature 330℃,roller gap 0.1 mm,pulling speed 20-25 mm/s and tension 7 N.T700/PEEK prepreg with the porosity of 1.8% was produced.SEM photograph confirms that the interface between T700 carbon fiber and PEEK bonded well,and the interlaminar shear strength was up to 73.43 MPa and longitudinal tensile strength was up to 1.71 GPa.