碳纤维/聚苯硫醚热塑性复合材料电阻焊接工艺

本文针对航空器结构用碳纤维/聚苯硫醚(CF/PPS)复合材料为研究对象,开展电阻焊接工艺研究;利用CF/PPS复合材料混编织物作为电阻元件,成功制备了CF/PPS复合材料层板电阻焊接接头;重点利用Taguchi方法和方差分析获取CF/PPS复合材料层板电阻焊接最佳工艺参数(电流为12 A,压力为1.5 MPa,时间为30 min)及各参数对焊接接头剪切强度的贡献(电流为83.37%,压力为9.55%,时间为6.02%)。最佳焊接工艺参数焊接的接头单搭接剪切强度约为17.88 MPa;同时,对最佳参数焊接试样(H-LSS)和较低剪切强度试样(L-LSS)的焊接接头截面和剪切失效断口形貌进行了观察和分析。结果表明:H-LSS试样的焊缝区域树脂填充和浸润良好,且主要剪切失效形式为层间剪切失效,即为纤维与树脂基体脱黏及CF/PPS织物复合材料断裂混合失效;L-LSS试样的焊缝区域树脂填充和浸润较差,存在较多空隙,且剪切失效形式为焊缝界面脱黏失效。

Resistance welding technology of carbon fiber/polyphenylene sulfide thermoplastic composites

The resistance welding technology of carbon fiber/polyphenylene sulfide (CF/PPS) composites for aircraft structure was studied. The resistance welding of CF/PPS composite laminates were successfully fabricated by using CF/PPS composite blended fabrics as resistance elements. Taguchi method and variance analysis were used to obtain the optimum parameters (current is 12 A, pressure is 1.5 MPa, time is 30 min) of resistance welding of CF/PPS composite laminates. The contribution of each welding parameters to the shear strength of welded were obtained (current is 83.37%, pressure is 9.55%, time is 6.02%). The single lap shear strength of welded was about 17.88 MPa with the optimum welding parameters. Meanwhile, the cross-section and shear failure fracture morphology of welded joints were observed and analyzed with the welding specimens with optimum parameters(H-LSS) and the lower shear strength specimen(L-LSS). The results show that the weld area of H-LSS sample is well filled and infiltrated, and the main failure mode is interlaminar shear failure, which involves damage to the adherends, the heating element or both of them. The welded area of L-LSS specimen has poor resin filling and wetting, and there are more voids, and the shear failure mode is interfacial shear failure and occurs at the interface between the weld and adherends.