固化製程參數對編織碳纖維強化複合材料的表面特徵及纖維體積百分率之影響

Abstract

由於纖維強化複合材料的諸多優點使其受到廣泛的使用，除了航太業外還有海上運輸業、汽車、運動用品等工業，以利用複合材料達到減重的目的。在許多實例中表面的特徵是很重要的，因量測時發現表面孔隙率對粗糙度的影響很大，固本實驗利用表面孔隙率當做評斷表面特徵的重要性質。另外纖維體積百分比也是一種纖維強化複合材料性質的評斷指標，複合材料主要承受力量的是強化材也就是纖維，當纖維體積百分率不高時，容易使樹脂承受過多力量而提前斷裂，導致層板受損。在本實驗因編織纖維複合層板的纖維體積含率量測較困難，改利用層板剖面的纖維面積百分比來比較纖維在層板中的含量。 本實驗使用Toray公司所生產，型號T300-3K的碳纖維1x1平織布與Huntsman公司所生產，型號AralditeRLY556的環氧樹脂溶液及AradurR917的硬化劑和DY 070的加速劑，利用手積法將樹脂塗佈於纖維布上，再使用真空袋熱壓法，製作複合材料層板。並對其固化製程中之參數對表面孔隙率及剖面纖維面積百分比進行探討。 實驗結果顯示編織纖維強化複合材料層板表面會有許多孔隙存在於富含樹脂區，固化壓力與升溫速率均會影響表面孔隙率，而最主要的影響變因是升溫速率。較低的升溫速率導致較低的表面孔隙率0.118%，因較高的升溫速率會提高樹脂在凝膠化前產生交聯反應的比率，導致樹脂的黏性上升，流動性減少，無法填補孔隙。較低的升溫速率導致較高的纖維面積百分比76.3%，與前面的論點相同，樹脂在凝膠化就開始交聯反應，導致樹脂的流動性降低並限制在層板間，多餘的樹脂無法因擠壓而被排出。

Composite materials are widely used in many applications, not only in the aerospace industry but also in the marine, automotive, sports goods industries. In many examples surface characteristic is critical, or at least important, since it reduces skin friction, drag and fuel consumption, in addition, a good surface appearance is a cosmetic necessity. Besides, fiber volume fraction is an important indicator of composites property. The fiber is used to reinforce material which is the main part in composite to bear the load. While the fiber volume fraction is low, the resin will break with too much loading and hence the composite will be damaged. The Toray T300-3K and Huntsman AralditeRLY556 epoxy resin, AradurR917 hardener, DY070 accelerator was used and applying hand lay-up process and hot compress vacuum bag to make composite. Then, investigate the influence of curing parameter on the surface characteristic and fiber volume fraction. It shows that there will be many porosity in the resin-rich area of the woven fiber –reinforced composite. The curing pressure and the heating rate both have effect on the surface porosity and heating rate is the most influential factor. The higher heating rate raise the cross-linking rate prior to gel and cause higher viscosity, lower resin flow as a result of surface porosity entrapment. The higher heating rate reduce the fiber volume fraction because of the high cross-linking rate prior to gel, which leads to low resin flow and restricted resin which can’t be squeezed out by compressing in the composite.