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钨酸锆对CFRP热膨胀性能的影响

Effect of Zirconium Tungstate on the Thermal Expansion Properties of Carbon Fiber Reinforced Polymer

【作者】 吴伟萍

【导师】 张东兴;

【作者基本信息】 哈尔滨工业大学 , 材料学, 2010, 硕士

【摘要】 碳纤维增强环氧树脂复合材料作为一种先进的结构材料,在航空航天等高新技术领域中得到了广泛的开发与应用。但由于CFRP复合材料中的基体固化后存在线膨胀系数大、质脆等缺点,使得基体与增强体的热膨胀系数相差较大,从而使复合材料的尺寸稳定性差,但是在航空航天领域有很多构件是在较宽的温度范围内工作,要求构件具有一定的热稳定性。材料微膨胀性能对提高航空航天结构和电子设备等的热几何稳定性有重要意义。自从发现具有负膨胀效应的材料以后,通过在基体中加入具有负膨胀效应的填料来降低基体的热膨胀系数以实现微膨胀性能越来越受到重视。钨酸锆(ZrW2O8)是一种在0.3~1050K温度范围内都具有很强的各向同性负热膨胀效应的材料,其负热膨胀系数为–8.7×10-6K-1。将ZrW2O8作为添加相与正膨胀材料复合成微膨胀材料已成为一个研究热点。本文利用高纯度ZrW2O8颗粒作为填料改性TDE-85环氧树脂,测试了不同含量下ZrW2O8/TDE-85的线膨胀系数和主要力学性能。试验结果表明:随着ZrW2O8含量的增加,浇注体的线收缩率和热膨胀系数不断下降,当降至一定值后趋于稳定。当ω(ZrW2O8):ω(TDE-85)=12:100时,浇注体材料的线收缩率和热膨胀系数趋于平缓,其值分别降低为0.15%和13.54×10-6℃-1。与未添加钨酸锆的TDE-85环氧树脂浇注体相比,浇注体试件的线收缩率和热膨胀系数分别降低了89.51%和63.13%。随着ZrW2O8含量的逐渐增加,浇注体材料的弯曲强度和拉伸强度则在增加到一定数值后开始下降。当ω(ZrW2O8):ω(TDE-85)=12:100时,浇注体材料的弯曲强度和拉伸强度达到最大值,其值分别增加至81.46MPa和132.76MPa。与未添加钨酸锆的TDE-85环氧树脂浇注体相比,浇注体试件的拉伸强度和弯曲强度分别提高了31.28%和22.54%。将配比为ω(ZrW2O8):ω(TDE-85)=12:100时的树脂液作为基体制备CFRP单向板复合材料,测试其热膨胀系数、弯曲强度、拉伸强度。结果表明:CFRP单向板的热膨胀系数下降为2.57×10-7℃,弯曲强度和拉伸强度分别增加为1687.06MPa和2483.15MPa。与未添加钨酸锆的CFRP复合材料相比,热膨胀系数降低了10.13%,弯曲强度提高了14.22%,拉伸强度提高了9.1%。并建立了复合材料热膨胀系数的理论预测方程。

【Abstract】 Carbon fiber reinforced epoxy composite materials that are advanced structural materials have been widely developed and applied in aerospace and other modern high-tech fields. However, the matrix of CFRP exist large linear expansion coefficient, crisp and other shortcomings after curing, that makes the difference of thermal expansion coefficient is large between the matrix and the reinforcement, so that the composite dimensional stability is poor, but there are a lot of structures require a thermal stability in aviation and aerospace fields, because they are work in a wild temperature range.The micro-expansion performance of materials is important to enhance the thermal geometric stability of aerospace structures and electronic equipment. Preparing micro-expansion materials is more and more attention since found to the materials which is negative thermal expansion effects. The method is that adding a kind of materials which is negative thermal expansion effect in matrix to reduce the thermal expansion coefficient of the matrix in order to achieve micro-expansion. Zirconium tungstate (ZrW2O8) exhibits isotropic negative thermal expansion in the temperature range of 0.3 to 1050 K, and its negative thermal expansion coefficient is about to -8.7×10-6K-1. The micro-expansion composite materials have become a new topic which was made by the ZrW2O8 as the added phase and the thermal expansion composite materials.In this paper, using the high purity ZrW2O8 particles as filler modified TDE-85 epoxy resin. The linear expansion coefficients, impact strength, tensile strength, tensile fracture surface of ZrW2O8/TDE-85 composite materials are measured under different levels. The results showed that, with the increase of the ZrW2O8 content, the linear shrinkage and thermal expansion coefficient of casting body is falling. It is stabilized when the linear shrinkage and thermal expansion coefficient reduced to a certain value. Whenω(ZrW2O8):ω(TDE-85)=12:100, the linear shrinkage and thermal expansion coefficient of casting body tends to smooth, and its value decreased to 0.15% and 13.54×10-6℃-1. The linear shrinkage and thermal expansion coefficient of casting body were reduced by 89.51 percent and 63.13 percent, compared to the specimens of TDE-85 epoxy resin that is not added the zirconium tungstate particles. With the increase of the ZrW2O8 content, the bending strength and tensile strength of cast body increases gradually. It is start to decline after a certain value. Whenω(ZrW2O8):ω(TDE-85)=12:100, the bending strength and tensile strength of cast body is the maximum, and its value increased to 81.46MPa and 132.76MPa. the bending strength and tensile strength of cast body is increased by 31.28% and 22.54%, compared to the specimens of TDE-85 epoxy resin that is not added the zirconium tungstate particles. Observed the section of tensile specimens using SEM equi[ment, the test restlts shows that the tensile fracture of cast body is a ductile fracture characteristics.In this experiment, it is prepared CFRP composite materials using the resin solution that is the prepreg with the ratio ofω(ZrW2O8):ω(TDE-85)=12:100. The linear expansion coefficients, impact strength, tensile strength, tensile fracture surface of CFRP composite materials are measured. The results showed that: The thermal expansion coefficient of CFRP composite materials dropped to 2.57×10-7℃, the flexural strength and tensile strength of CFRP composite materials increased to 1687.06MPa and 2483.15MPa. The thermal expansion coefficient of CFRP composite materials is reduced by 10.13%, the bending strength of CFRP composite materials increased by 14.22%, the tensile strength of CFRP composite materials increased by 9.1%, compared to the specimens of of CFRP composite materials that is not added the zirconium tungstate particles.

  • 【分类号】TB332
  • 【被引频次】1
  • 【下载频次】260
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