超声处理对RTM成型复合材料界面性能的影响

在RTM成型过程中采用超声技术。探讨了超声处理的最佳工艺参数,着重研究超声处理对RTM成型复合材料界面性能的影响。结果表明,在RTM成型过程中采用超声技术增加了树脂对纤维增强体的浸润性,使树脂中的空气和成型过程中产生的气泡易于排出,从而减少了复合材料的孔隙率,进而改善复合材料的界面性能。     

腐蚀算法在重建一类特殊管道中的应用

针对一类特殊而不能直接对其观察的管道（如动物的血管），为了准确了解其内部特征和形态，借助计算机给出了一种用腐蚀算法来重建管道原形的方法。这种方法简单易行，而且精确度高。     

定向凝固Al/C复合材料研究

本文首次进行了Al/C(SiC)复合材料定向凝固,研究了复合材料定向凝固过程以及组织形态与凝固速率的关系,获得了纤维束间胞晶和不同间距的树枝晶,发现非润湿系统复合材料定向凝固后性能降低,文中对其机制进行了探讨.     

Rheology in Processing of in Situ Composites of Polypropylene and Low Melting Poing Metals

The low melting point metallic tin powder or alloy of tin and lead was blended with polypropy-lene. A kind of in situ composite has been prepared. The variations of torque were studied when the composites were mixed in Haake torque rheogeniometer. By way of capillary extrusion, effects upon rheology of the in situ com-posites of the low melting point metals (LMPM) and coupling agent for their different variety and content, were investigated. From flow curves, the results indicate that in situ composites mixed with the LMPM are a kind of pseudoplastic fluid. If the LMPM were melted, the higher the content of the LMPM , the lower apparent viscosity of composites. Meanwhile, when the coupling agent is added into composites, the viscosity of composite will go up first and drop then. This shows that the LMPM have a promoter flow action on the polypropylene.     

SiC颗粒增强铝基复合材料切削表面分形维数及其与抗磨损性能的关系

做为一种耐磨性能很好的材料 ,SiC颗粒增强铝基复合材料切削加工表面具有分形特征。实际研究表明SiC颗粒增强铝基复合材料切削加工表面分形维数与抗磨损性能有密切关系 ,本文还分析了表面分形维数越大其抗磨损性能越强的机理。     

Thermomechanical stress fields in high-temperature fibrous composites. I: Unidirectional laminates

This two-part paper presents a closed-form procedure for evaluation of estimates of local thermomechanical stress fields in two-phase fibrous composites and laminates. The first part is concerned with a unidirectional elastic laminate subjected to uniform mechanical loads and to uniform changes in temperature. Both phases are assumed to be elastic, with temperature-dependent moduli and expansion coefficients; the solution reflects the influence of thermomechanical interactions. Exact solutions are not possible for any real system, because the local geometry is not known in detail. Instead, estimates of the fields are found from a modified Mori-Tanaka approximation. Examples are presented for two SiC/Ti---Al---Nb composites. Local stresses of interest are found after cooling from fabrication to room temperature. The presence of local yielding, and the influence of coupling terms on the local stress magnitudes are examined. Extension of the results to laminated plates is presented in Part II (Dvorak, G.J., Chen, T. & Teply, J., Composites Science and Technology, 43 (1992) 359–368, this issue).     

真空铸造高强度C／Mg复合材料

本文介绍用真空铸造法制造抗拉强度超过１０００ＭＰａ的高强度Ｃ／Ｍｇ复合材料。将Ｔ３００纤维经Ｃ－Ｓｉ－Ｏ梯度涂层处理后单向排布于型腔内，在真空下注入ＺＭ—５合金液，凝固后即得Ｃ／Ｍｇ复合材料零件或试样。试样的抗拉强度在纤维体积分数为０．３５时达１０５０ＭＰａ。本文讨论Ｃ－Ｓｉ－Ｏ梯度涂层对获得高强度复合材料的作用。     

The effect of temperature on the dynamic characteristics of heat-resistant thermoplastic composites

Two thermoplastic and two thermosetting fibrereinforced plastic composites were subjected to dynamic tests over a wide range of temperature, covering both cryogenic and hot environments. The thermal behaviour of each composite, as indicated by its dynamic mechanical properties, was assessed individually, and was compared collectively with that of the other composites.     

用于X光激光实验的反射式线聚焦光学系统的设计和分析

基于三维光线追迹的象差计算,对卢瑟福实验室用离轴球面反射线聚焦系统作了分析。然后,首次提出了用于X光激光实验的两类新的反射式线聚焦构型,即反射式光楔列阵和光锥列阵系统,并作了计算。最后,对所得结果作了比较和讨论。     

一种碳－碳复合材料长寿命防氧化涂层的失效机制

用液相法联合ＣＶＤ法和硅化法制备了一种碳－碳复合材料复合梯度涂层，在此基础上对这种涂层在氧化过程中的失效机制进行了研究．结果表明：氧化层与液相层界面反应生成的气相产物是涂层失效的根本原因界面上气泡的不均匀形核、长大和破裂导致涂层表面出现孔洞．孔洞处气泡优先形核、长大和破裂并发展成为缺陷而使涂层失效