湿法分层缠绕T700/环氧复合材料微波固化工艺及性能

Microwave curing process and properties of T700/epoxy composites by wet filament lamination winding

针对大厚度固体火箭发动机壳体制造周期长的缺点,本文提出分层缠绕微波预固化工艺。以固化度为依据,结合壳体缠绕规律及微波吸收效率,筛选出[90°2/±20°]的分层缠绕基元。分层缠绕中需经多次微波辐射,考虑热传导或弱微波效应对已缠绕层固化度的影响,制定出升温速率为5℃/min、由室温升至90℃的微波预固化工艺,后处理采用热固化:160℃保温1 h。在微波固化试样制备时间(均不考虑降温时间)比热固化缩短近一半的情况下,T700碳纤维复合材料微波固化与热固化试样力学性能基本一致:微波固化层合板拉伸强度为1.84 GPa,热固化层合板拉伸强度为1.76 GPa;微波固化层合板弯曲强度为1.20 GPa,热固化层合板弯曲强度为1.17 GPa;微波固化NOL环拉伸强度为2.94 GPa,热固化NOL环拉伸强度为3.08 GPa;微波固化NOL环层间剪切强度为76.1 MPa,热固化NOL环层间剪切强度为75.6 MPa。扫描电镜照片表明,两种固化方式下纤维-基体界面结合良好。由于微波固化不依赖于热传导或热对流,因此可以在较短的时间内达到与热固化试样相当的力学性能。

In this paper,the rapid manufacturing of large-size solid rocket motor shell is the research background.Aiming at the problems of long curing cycle and high production cost in traditional heat curing,a layered microwave pre-curing process is proposed to shorten the manufacturing cycle and maintain excellent performance.With the help of differential scanning calorimeter,based on the curing degree,combined with the shell winding law and microwave absorption efficiency,the layered winding element of[90°2/±20°]was selected.Considering the influence of heat conduction and microwave effect on the curing degree of the wound layer,a microwave pre-curing process with heating rate of 5℃/min and rising from room temperature to 90℃was determined.The post-treatment was heat curing by holding at 160℃for 1 h.Microwave curing and heat curing composite laminates and NOL rings were prepared.When the preparation time of samples cured by microwave(regardless of cooling time)is nearly half shorter than that of samples cured by heat,the mechanical properties of samples cured by microwave and heat are basically the same.Because of the bulk heating characteristics of microwave curing,it can achieve the mechanical properties equivalent to that of the heat cured samples in a short time.