用动态介电分析技术监控复合材料的固化过程

 以高模量碳纤维为增强体的复合材料具有较钢、铝、钛合金高得多的比强度,比模量和耐疲劳性能,对于减轻飞机的结构重量来说,这是一种很有发展前途的飞机结构材料。据专家们推测,到本世纪末,作为高性能战斗机结构用的复合材料,将从目前的百分之几上升到百分之五十左右。

MONITORING CURE PROCESS OF COMPOSITES WITH DYNAMIC DIELECTRIC ANALYSIS TECHNIQUE

A dynamic analysis monitoring technique is presented for autoclave cure process of composites constructed of T300/8DTT carbon-fiber epoxy resin pre-preg.On the basis of the monitoring technique and with a domestic monitor model JK2107,the appropriate time of pressure application can be chosen and then the "optimum band of pressure application" can be determined successfully by a small number of experiments.During cure process of thermosetting resin system,a dielectric loss tan- gent vs time curve can be obtained with the monitor and the "optimum band of pressure application" can be found from the curve.Thus it is po-ssible to choose the proper time of pressure application by the loss tangent,and composite plates with a low void content are made by monitoring the time chosen.This paper proposes a new way to move the optimum band of pressure application" to the peak of loss tangent curve or behind it by increasing frequency given by monitor JK2107 and to use the peak of the curve as a reference signal.Therfore,the time of pressure application can be controlled exactly and the quality of composite plates is guaranteed steadily in this way.