可剥布对T300/Cycom 970环氧树脂复合材料胶接性能的影响

在商用飞机复合材料结构制造过程中,可剥布在复合材料共胶接和二次胶接的表面处理过程中应用越来越广泛,逐步替代传统打磨方式。然而在实际应用中,可剥布与复合材料树脂体系之间存在一定的匹配性,经不同可剥布处理后的复合材料表面胶接性能存在较大差异。为研究其对胶接性能的影响,选用四种航空用可剥布对复合材料进行表面处理,采用热压罐工艺制备T300/Cycom 970环氧复合材料层压板,选取同一种航空用胶膜进行胶接。按照ASTM剥离测试和单搭接剪切测试标准,对T300/Cycom 970环氧复合材料胶接结构的性能进行测试,采用接触角测试、SEM和X射线能谱测试(XPS)分别对复合材料层压板制件和可剥布织物的表面润湿性、表面形貌和表面元素进行测试与分析。结果表明:选用聚酯湿可剥布处理后的T300/Cycom 970环氧复合材料胶接性能最佳;可剥布织物及涂层的残留会影响复合材料胶接性能;可剥布处理能改善复合材料表面润湿性,提高表面能,但并不能保障胶接质量;可剥布编织形式直接影响复合材料表面形貌,决定其表面粗糙度,对复合材料胶接性能也有较大的影响。

Effect of peel plies on bonding properties of T300/Cycom 970 epoxy composites

In the manufacturing process of composite structures for commercial aircraft,peel ply surface treatment for co-bonding and secondary bonding of composites is becoming more common and gradually substitutes the traditional method such as grinding.And it is found that potential matching exists between different peel plies and composite resin systems in practical application.As a result,varied bonding properties were observed on composite surface with different peel plies after treatments.In order to study the effects of peel ply on the bonding performance,T300/Cycom 970 epoxy resin composite laminates were fabricated using the autoclave process.First,four peel plies and an adhesive film for commercial aircraft were chosen for surface treatment and bonding,respectively.Second,the structure properties of T300/Cycom 970 epoxy laminate specimens after bonding were tested by stripping tests and single lap shear tests according to the ASTM standards.Finally,contact angle test,scanning electron microscopy (SEM) and X-Ray Photo Spectroscopy (XPS) were applied to characterize the surface wettability,morphology and element analysis for composite laminates and peel plies.The results show that the bond quality of the T300/Cycom 970 epoxy composite sample which are treated with polyester wet peel ply is the best,and the residual of peel plies fabric and coating has negative effect on the T300/Cycom 970 epoxy composite bonding performance.Although peel ply surface treatment can improve the surface wettability and the surface energy,the improvement of wettability cannot guarantee the bond quality.T300/Cycom 970 epoxy composite surface topography and roughness are affected directly by peel ply weave pattern,which produce an effect on the bond quality of the composites.