胶接具有避免应力集中、减重等优点,在复合材料的连接领域得到广泛应用。但复合材料在胶接前的储存过程中会吸湿,从而使胶接试验件的胶接性能下降。因此,在胶接前需要对复合材料进行烘干处理。在复合材料的吸湿-烘干过程中,胶接界面与胶膜的匹配性是亟待解决的问题。首先选用60001干可剥布和EA9895湿可剥布对复合材料进行表面处理,然后在26℃/65% RH(RH为相对湿度,下同)和70℃/85% RH环境下进行吸湿-烘干处理,最后用EA7000胶膜胶接,得到胶接试验件并进行胶接性能测试。研究表明,吸湿后复合材料的胶接界面与胶膜的匹配性变差,其机理为复合材料内部的水分进入胶膜,进而破坏胶膜中载体纤维与树脂的界面结合,降低了胶膜本身的力学性能。在26℃/65% RH环境下吸湿-烘干后,胶接试验件的胶接性能基本可以恢复,使用EA9895湿可剥布处理的胶接界面与胶膜的匹配性优于60001干可剥布。在70℃/85% RH环境下吸湿-烘干后,胶接试验件的胶接性能恢复程度较低,胶接界面与胶膜的匹配性较差。
Adhesive bonding is widely used in the connection of composites due to its advantages of avoiding stress concentration and weight reduction.However,composites absorb moisture during storage before bonding,which can reduce the bonding performance of the joints.Therefore,composites need to be dried before bonding.During moisture adsorption-drying treatment of composites,the matching performance of the bonding interface and the adhesive film is an urgent problem to be solved.In this work,dry peel ply 60001 and wet peel ply EA9895 were firstly used to treat the surface of the composites,and then moisture absorption-drying treatment was carried out at 26℃/65% RH (RH stands for relative humidity,the same below) and 70℃/85% RH.Finally,the above composites were bonded with EA7000 adhesive film to obtain bonded specimens for evaluating the bonding performance.The results indicated that the matching performance of the bonding interface and the adhesive film became worse after moisture adsorption of composites.The mechanism was that the moisture absorbed by composites entered the adhesive film,thereby worsening the interface between the carrier fiber and the resin and reducing the mechanical properties of the adhesive film itself.After moisture absorption-drying at 26℃/65% RH,the bonding performance of the bonded specimens could be basically restored,and the matching performance of adhesive film and the bonding interface treated with EA9895 was better than that treated with 60001.After moisture absorption-drying at 70℃/85% RH,the recovery of the bonding performance of the bonded specimens was lower,and the matching performance was poorer.
[1] Yudhanto A,Almulhim M,Kamal F,et al.Enhancement of fracture toughness in secondary bonded CFRP using hybrid thermoplastic/thermoset bondline architecture[J].Compo-sites Science and Technology,2020,199:108346.
[2] 乔海涛,邹贤武.复合材料胶接技术的研究进展[J].宇航材料工艺,2010,40(2):11-14.
[3] 邵南,高堂铃,付刚,等.低面密度中温固化载体结构胶膜的性能研究[J].化学与粘合,2018,40(3):182-184.
[4] Benard Q,Fois M,Grisel M,et al.Influence of the polymer surface layer on the adhesion of polymer matrix composites[J].Journal of Thermoplastic Composite Materials,2009,22(1):51-61.
[5] 翟全胜,苗春卉,崔海超,等.基于表面改性的国产T800碳纤维/高韧性环氧树脂复合材料胶接性能[J].复合材料学报,2021,38(7):2162-2171.
[6] Holtmannsptter J,Czarnecki J V,Wetzel M,et al.The use of peel ply as a method to create reproduceable but contaminated surfaces for structural adhesive bonding of carbon fiber reinforced plastics[J].Journal of Adhesion,2013,89(2):96-110.
[7] Kanerva M,Saarela O.The peel ply surface treatment for adhesive bonding of composites:a review[J].International Journal of Adhesion & Adhesives,2013,43:60-69.
[8] 刘宇婷.可剥布对复合材料胶接质量的影响[D].上海:东华大学,2017.
[9] 王旭,陈璐圆,陈萍,等.民用航空复合材料成型用可剥布评价与选用[J].航空制造技术,2015,58(19):88-91.
[10] Armstrong K B.Effect of absorbed water in CFRP composites on adhesive bonding[J].International Journal of Adhesion and Adhesives,1996,16(1):21-28.
[11] Mostovoy S,Ripling E J.Influence of water on stress corrosion cracking of epoxy bonds[J].Journal of Applied Polymer Science,1969,13(6):1083-1111.
[12] Parker B M.The strength of bonded carbon fibre composite joints exposed to high humidity[J].International Journal of Adhesion & Adhesives,1990,10(3):187-191.
[13] Johnson W S,Butkus L M.Considering envirnmental conditions in the design of bonded structures:a fracture mechanics approach[J].Fatigue & Fracture of Engineering Materials & Structures,2010,21(4):465-478.
[14] 王英男,潘利剑,刘钧天,等.吸湿条件下可剥布处理对复合材料胶接性能的影响[J].玻璃钢/复合材料,2019,309(10):92-97.
[15] Liu S F,Cheng X Q,Zhang Q,et al.An investigation of hygrothermal effects on adhesive materials and double lap shear joints of CFRP composite laminates[J].Composites Part B-Engineering,2016,91:431-440.
[16] Budhe S,Rodríguez-Bellido A,Renart J,et al.Influence of pre-bond moisture in the adherents on the fracture toughness of bonded joints for composite repairs[J].International Journal of Adhesion and Adhesives,2014,49:80-89.
[17] Blackman B R K,Johnsen B B,Kinloch A J,et al.The effects of pre-bond moisture on the fracture behaviour of adhesively-bonded composite joints[J].The Journal of Adhesion,2008,84(3):256-276.
[18] Parker B M.The effect of composite prebond moisture on adhesive-bonded CFRP-CFRP joints[J].Composites,1983,14(3):226-232.
[19] ASTM International.Standard test method for mode Ⅰ interlaminar fracture toughness of unidirectional fiber-reinforced polymer matrix composites:ASTM D5528-13[S].West Conshohocken:ASTM International,2013.
[20] Chen C,Zhang W,Li Y,et al.The influence of moisture absorption-drying of composite materials on the bonding performance of the joints[J].Macromolecular Materials and Engineering,2022,308:2200463.
[21] 乔琨.改性高温高韧环氧树脂及其CF增强复合材料环境适应性研究[D].济南:山东大学,2013.
[22] 刘宇婷,潘利剑,胡秀凤,等.可剥布对T300/Cycom 970环氧树脂复合材料胶接性能的影响[J].复合材料学报,2017,34(5):996-1002.
[23] 关世伟.胶接接头破坏分析[J].中国胶粘剂,2015,24(2):57-58.
[24] 余永波,晏冬秀,陈萍.吸湿对复合材料胶接影响研究及机理探索[J].纤维复合材料,2021,38(2):34-38.
[25] Diamant Y,Marom G,Broutman L J.The effect of network structure on moisture absorption of epoxy-resins[J].Journal of Applied Polymer Science,1981,26(9):3015-3025.
[26] 乔海霞.玻璃纤维/碳纤维混杂增强复合材料电缆芯老化性能研究[D].长沙:国防科技大学,2006.
[27] Moy P,Karasz F E.Epoxy-water interactions[J].Polymer Engineering and Science,1980,20(4):315-319.
[28] Zhou J,Lucas J P.Hygrothermal effects of epoxy resin.Part Ⅰ:the nature of water in epoxy[J].Polymer,1999,40(20):5505-5512.
[29] Antoon M K,Koenig J L,Serafini T.Fourier-transform infrared study of the reversible interaction of water and a crosslinked epoxy matrix[J].Journal of Polymer Science:Polymer Physics Edition,1981,19(10):1567-1575.
[30] 刘钧天.复合材料胶接质量和胶接面性质研究[D].上海:东华大学,2018.
基金资助
国家商用飞机制造工程技术研究中心创新基金(COMAC-SFGS-2020-35)
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