RFI工艺用双马来酰亚胺树脂膜

以热塑性聚醚砜树脂（PES）和聚酰亚胺树脂（PI）改性4508树脂，制得了适用于树脂膜熔渗（RFI）工艺的高性能树脂基体膜。该树脂膜室温性质稳定，发粘点高，任意弯曲不脆裂。其固化树脂的力学性能、耐热性和耐湿热性能优良，所制得的玻璃布复合材料综合性能优异。     

辐射剂量对环氧树脂电子束固化行为的影响

分析了电子束剂量对环氧树脂体系辐射固化行为的影响规律。研究结果表明，电子束辐射过程中，温度由树脂辐射体系表面向内部逐渐降低，随着辐射剂量提高，树脂体系温度上升，辐射表面与内部的温度梯度加大，高辐射剂量下的温度变化缓慢。树脂辐射固化层厚度以及在相同厚度的固化程度均随辐射剂量增加，但增幅逐渐变小，树脂辐射固化度沿固化深度会加速下降。     

环丁烷四羧酸二酐类聚酰亚胺表面取向性能研究

以1，2，3，4-环丁烷四羧酸二酐为原料合成了一个系列三种聚酰亚胺取向材料。研究了它们在不同固化温度、固化时间及摩擦强度下的表面取向性能，获得了1.0～105°范围的预倾角。结果表明预倾角随固化温度升高、固化时间延长而zk大，随摩擦强度先zk大后减小。三种聚酰亚胺都具有良好的表面取向性能，分别适用于TN及STN型液晶显示。     

电子束固化树脂基复合材料中碳纤维表面改性研究

利用阳极氧化方法和偶联剂对碳纤维表面的物理和化学性质进行改性，采用原子力显微镜（AFM）和X射线光电子能谱（XPS）分析了碳纤维表面改性前后的形貌和化学成分的变化，利用Keaelble法计算了碳纤维的表面能。研究结果表明，阳极氧化改性的碳纤维表面粗糙度增加，表面活性；表面活性官能闭增多，表面能中极性成分增加明显，碳纤维表面引入的活性氮和化学吸附的碱性物质使电子束固化复合材料界面处的引发剂中毒，复合材料界面性能减弱，与电子束固化工艺相匹配的偶联剂在碳纤维与树脂基体之间形成化学桥，使电子束固化复合材料界面性能得到明显提高。     

表面活性剂对环氧树脂固化反应及性能的影响EI

用热分析手段研究了非离子型表面活性剂Triton X-100对4,4′-二氨基二苯甲烷环氧树脂(TGDDM)/4,4′-二氨基二苯基砜(DDS)环氧树脂固化行为和性能的影响。DSC非等温固化反应动力学研究表明,1%(质量分数,下同)的表面活性剂对固化反应有促进作用,但10%的表面活性剂抑制了固化反应。DSC的等温固化反应中,表面活性剂抑制固化反应的进行。TGA研究表明,表面活性剂的加入对环氧树脂热稳定性影响很小。DMTA研究结果说明,表面活性剂在环氧树脂中起到了增塑剂的作用,并且和环氧树脂是互容的,表面活性剂的加入使得环氧树脂的储存模量减小,玻璃化温度逐渐降低。     

表面活性剂对环氧树脂固化反应及性能的影响

用热分析手段研究了非离子型表面活性剂Triton X-100对4,4′-二氨基二苯甲烷环氧树脂(TGDDM)/4,4′-二氨基二苯基砜(DDS)环氧树脂固化行为和性能的影响。DSC非等温固化反应动力学研究表明,1%(质量分数,下同)的表面活性剂对固化反应有促进作用,但10%的表面活性剂抑制了固化反应。DSC的等温固化反应中,表面活性剂抑制固化反应的进行。TGA研究表明,表面活性剂的加入对环氧树脂热稳定性影响很小。DMTA研究结果说明,表面活性剂在环氧树脂中起到了增塑剂的作用,并且和环氧树脂是互容的,表面活性剂的加入使得环氧树脂的储存模量减小,玻璃化温度逐渐降低。     

系列有机硅改性紫外光-热混杂固化树脂的表面性能

以有机硅改性丙烯酸环氧单酯为树脂配制了一系列紫外光-热混杂固化体系,用红外光谱(FT-IR)表征了固化过程特征吸收峰的变化;测试了有机硅链段的长短对固化膜表面水接触角、表面能和硅元素分布的影响。结果表明,在相同稀释剂条件下,丙烯酸环氧单酯光-热固化膜的表面水接触角为62.53°,表面能为47.62 mN/m,有机硅改性丙烯酸环氧单酯体系光-热固化膜的表面水接触角最高可达106.75°,相应的表面能为18.62 mN/m。有机硅改性体系中随着有机硅链段的增长,固化膜表面水接触角和表面硅元素含量逐渐增加,表面能则逐渐下降,表面元素分析也显示固化膜表面硅元素含量要比背面的高。     

系列有机硅改性紫外光-热混杂固化树脂的表面性能EI北大核心CSCD

以有机硅改性丙烯酸环氧单酯为树脂配制了一系列紫外光-热混杂固化体系,用红外光谱(FT-IR)表征了固化过程特征吸收峰的变化;测试了有机硅链段的长短对固化膜表面水接触角、表面能和硅元素分布的影响。结果表明,在相同稀释剂条件下,丙烯酸环氧单酯光-热固化膜的表面水接触角为62.53°,表面能为47.62 mN/m,有机硅改性丙烯酸环氧单酯体系光-热固化膜的表面水接触角最高可达106.75°,相应的表面能为18.62 mN/m。有机硅改性体系中随着有机硅链段的增长,固化膜表面水接触角和表面硅元素含量逐渐增加,表面能则逐渐下降,表面元素分析也显示固化膜表面硅元素含量要比背面的高。     

碳纤维在电子束辐射过程中对树脂基复合材料界面性能的影响

采用XPS和Raman分析了电子束辐射对碳纤维表面性质的影响，研究了碳纤维与基体树脂之间的不充分接触对电子束固化复合材料层间剪切强度的影响，同时分析了碳纤维表面吸附的水分，碳纤维与基体树脂之间的空隙率和碳纤维表面在碳酸氢铵电解液中进行阳极氧化处理后对电子束固化复合材料界面性能的影响，分析了碳纤维表面在电子束辐射过程中与树脂基体的作用机理。     

EB固化技术及EB油墨

1.电子束固化技术 电子束固化是以电束（EB）为辐射源，诱导经特殊配制的固含量为100%的应性液体快速转变成固体的过程。EB固化与其他固化方法相比具有下列特点： （1）固化所需的EB能量范围为150～300keV，它以近似光速到达固化物质表面，不仅不受涂层颜色的限制，而且还能固化纸张或其他基材内部涂料和不透明基材（如铝箔）之间的粘合剂；     

Modelling of failure mode transition in ballistic penetration with a continuum model describing microcracking and flow of pulverized media

An Erratum has been published for this article in International Journal for Numerical Methods in Engineering 2002; 55(4):499–501. A new continuum model to describe damage, fragmentation and large deformation of pulverized brittle materials is presented. The multiple‐plane‐microcracking (MPM) model, developed by Espinosa, has been modified to track microcracking on 13 orientations under high pressure, high strain rate and high deformation. This model provides the elastic and inelastic response of the material before massive crack coalescence. When pulverization occurs, the constitutive response is modelled by means of a visco‐plastic model for granular material, which is a generalization to three dimensions of the double‐sliding theory augmented by a consolidation mechanism. The initialization of the granular model is governed by a yield surface at the onset of massive crack coalescence. This is accomplished by examining a representative volume element, modelled using the MPM model, in compression‐shear. The main advantage of this approach is to keep a continuum model at all stages of the deformation process and thus avoid the difficulties of crack representation in a discrete finite element code. This model has been implemented in LS‐DYNA and used to examine interface defeat of long rod penetrators by a confined ceramic plate. The numerical simulations are compared to experiments in order to identify failure modes. The model parameters were obtained independently by simulating plate and rod impact experiments. The proposed model captures most of the physical observations as well as failure mode transition, from interface defeat to full penetration, with increasing impact velocity. Copyright © 2002 John Wiley & Sons, Ltd.     

An efficient solver of the saturation equation in liquid composite molding processes

A major issue in Liquid Composite Molding Process (LCM) concerns the reduction of voids formed during the resin filling process. Reducing the void content increases the quality of the composite and improves its mechanical properties. Most of modeling efforts on process simulation of mold filling has been focused on the single phase Darcy’s law, with resin as the only phase, ignoring the formation and transport of voids. The resin flow in a partially saturated region can be characterized as two phase flow through a porous medium. The mathematical formulation of saturation in LCM takes into account the interaction between resin and air as it occurs in a two phase flow. This model leads to the introduction of relative permeabilities as a function of saturation. The modified saturation equation is obtained as a result, which is a non-linear advection-diffusion equation with viscous and capillary phenomena. In this work, a flux limiter technique has been used to solve a modified saturation equation for the LCM process. The implemented algorithm allows a numerical optimization of the injected flow rate which minimizes the micro/macroscopic void formation during mold filling. Some preliminary numerical results are presented here in order to validate the proposed mathematical model and the numerical scheme. This formulation opens up new opportunities to improve LCM flow simulations and optimize injection molds.     

低温等离子体表面处理对超高分子量聚乙烯纤维-环氧树脂粘接性能的影响及机理

超高分子量聚乙烯纤维与环氧树脂的粘接性能很差,给高性能轻型复合材料的研制带来困难。本文采用低温等离子体对纤维表面进行处理。结果表明,处理后的纤维表面能提高,使环氧树脂能良好地浸润纤维,纤维与环氧树脂间粘接强度可提高5-8倍。粘接性能改善的原因是:由表面引入的多种含氧基团所形成的化学键力,由表面刻蚀坑产生的机械嵌合力。     

光固化快速成型中光敏树脂固化机理研究

合成了一种适于光固化快速成型的环氧丙烯酸光敏树脂,探讨了该光敏树脂的紫外光固化机理,用SEM表征了树脂体系固化后的微观结构,用红外光谱(FTIR)对树脂体系固化过程进行了分析。研究结果表明:光敏树脂经紫外光固化后,呈交联的、不规则体型网络结构;树脂在光固化过程中,光引发剂的含量在一定数值范围内与光敏树脂中C=C双键的转化率成正比。     

低温等离子体表面处理对超高分子量聚乙烯纤维-环氧树脂粘接性能的影响及机理

超高分子量聚乙烯纤维与环氧树脂的粘接性能很差,给高性能轻型复合材料的研制带来困难。本文采用低温等离子体对纤维表面进行处理。结果表明,处理后的纤维表面能提高,使环氧树脂能良好地浸润纤维,纤维与环氧树脂间粘接强度可提高5-8倍。粘接性能改善的原因是:由表面引入的多种含氧基团所形成的化学键力,由表面刻蚀坑产生的机械嵌合力。      

Finite element numerical simulation on thermo-mechanical behavior of steel billet in continuous casting mold

The thermo-mechanical behavior of a thin, growing shell during the early stages of solidification in a continuous casting mold is very important to the ultimate quality of the final billet. A two-dimensional, transient finite element model has been developed to treat the heat flow and deformation of the solidifying shell in the continuous casting billet mold as a coupled phenomena. The major application of the model is to predict the extent of the gap between the mold and the shell and focus on the influence of mold taper on the thermo-mechanical behavior of the steel billet to help to understand the formation of off-corner cracks and break-outs in the solidifying shell. The calculations indicate that the gap is initially formed at the corner of the billet, where heat transfer is greatly reduced. Insufficient mold taper contributes to a hot spot in the off-corner region, which corresponds to the lowest shell thickness. At the same time, the solidifying front on the diagonal of the billet is subjected to an excessive mechanical strain, which causes the off-corner cracks and even the break-outs.     

Finite element numerical simulation on thermo-mechanical behavior of steel billet in continuous casting mold

The thermo-mechanical behavior of a thin, growing shell during the early stages of solidification in a continuous casting mold is very important to the ultimate quality of the final billet. A two-dimensional, transient finite element model has been developed to treat the heat flow and deformation of the solidifying shell in the continuous casting billet mold as a coupled phenomena. The major application of the model is to predict the extent of the gap between the mold and the shell and focus on the influence of mold taper on the thermo-mechanical behavior of the steel billet to help to understand the formation of off-corner cracks and break-outs in the solidifying shell. The calculations indicate that the gap is initially formed at the corner of the billet, where heat transfer is greatly reduced. Insufficient mold taper contributes to a hot spot in the off-corner region, which corresponds to the lowest shell thickness. At the same time, the solidifying front on the diagonal of the billet is subjected to an excessive mechanical strain, which causes the off-corner cracks and even the break-outs.     

Finite Element Numerical Simulation for Influence of Mold Taper on Thermomechanical Behavior of Steel Billet in Continuous Casting Process

The thermomechanical behavior of the thin, growing shell during the early stages of solidification in the continuous casting mold is very important to the ultimate quality of the final billet. A two-dimensional, transient finite element model has been developed to treat the heat flow and deformation of solidifying shell in the continuous casting billet mold as coupled phenomena. The major application of the model is to predict the extent of the gap between the mold and the shell, and focus on the influence of mold taper on the thermomechanical behavior of the steel billet to help understand the formation of off-corner cracks and breakouts in the solidifying shell. The calculations indicate that the gap is initially formed at the corner of the billet, where heat transfer is greatly reduced. Insufficient mold taper contributes to a hot spot in the off-corner region, which corresponds to the thinnest shell thickness. Meanwhile, the solidifying front along the diagonal of the billet is subjected to an excessive mechanical strain, which causes the off-corner cracks and even the breakouts.     

酚醛树脂基碳分子筛的研究

以酚醛树脂为原料,采用固化、干馏、粉碎、造粒、炭化和碳沉积制备工艺、制备了用于空气分离的碳分子筛,采用单塔变压吸附法及重量法对自制的碳分子筛及日本样品碳分子筛的空分性能进行了比较,结果表明：以酚醛树脂为原料,可制得选择吸附系数大,吸附容量大,强度好的优质碳分子筛,其性能已达到或超过日本样品碳分子筛水平。     

Sedimentation speed of a free dendrite growing in an undercooled melt

Free equiaxed dendrites in solidifying alloy melts are subjected to hydrodynamic effects as a result of gravity. The sedimentation of dendrites is one such effect and believed to be a cause of macro segregation in partitioning alloys. A novel computational model is proposed to estimate the settling speed of free dendrites at moderate Reynolds numbers. Growth of the dendrite, momentum changes, internal solid fraction evolution within a spherical dendrite envelope of changing diameter, and surface morphology of the dendrite while settling are taken into account in the development of the model. Comparison with results from a series of equiaxed dendrite settling experiments, on solidifying transparent alloy analogues to metals, shows good agreement between predicted and experimental settling speeds. The correlation between surface morphology of the dendrite which affects drag force and the physical parameters of the settling dendrite is studied. The feasibility of applying the proposed model to metallic systems is also explored and the outlook is positive.