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挤压铸造短纤维增强金属基复合材料浸渗过程分析 总被引:3,自引:0,他引:3
在分析挤压铸造金属基复合材料浸渗条件的基础上,建立了液态金属在短纤维预制件中的浸渗和压力分布模型,计算结果表明:(1)当外加压力不足以使短纤维预制件产生变形之前,其浸渗距离和浸渍前端的压力分别为:Xf=1-F/1-V'f∫^t0udt和Ps=μu/K'0·1-F/1-V'f∫^t0udt-4Vf0γcosθ/df(1-Vf10)(2)当外加压力使短纤维预制件产生变形之后,其浸渗距离和浸渗前端的压力 相似文献
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使用CVD技术提高纤维增强陶瓷基复合材料的密度是很困难的,因为它很难使反应气体完全渗入到基体里面,这是由于“瓶颈”效应所致,即CVD过程阻塞了基体表面的小气孔,进而封闭了通向大气孔的入口,为此提出了一种新的方法位控CVD(PCCVD),来克服上述通过控制反应气体通道位置试样的加热位置,从而达到控制沉积位置,使沉积界面始终处于开孔状态,使用PCCVD技术制造的C/SiC复合材料,实际密度可达到其理论 相似文献
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F.A. Mohamed 《Advanced Engineering Materials》2002,4(9):651-657
The creep properties of powder metallurgy (PM) discontinuous SiC‐Al alloys (whisker and particulate) and their Al matrices have been the subject of many studies recently that have aimed not only at assessing the potential of the PM SiC‐Al alloys for use as high temperature materials but also at identifying the origin creep strengthening in such materials. As a result of these studies, several sets of experimental results are now available. This paper reviews some of the results. Emphasis is placed on the identification of issues related to early work and on efforts made recently to clarify them. In addition, recent developments regarding the roles played by SiC particulates and the Al alloy matrix during the creep of a PM SiC‐Al composite are discussed. 相似文献
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A processing route has been developed for the fabrication of metallic fibre mat reinforced glass matrix composites. For the
model experiments reported here, a commercially available satin woven stainless steel 316L fibre mat was used as the reinforcement
and soda-lime glass as the matrix. The process involves two steps: (1) the infiltration of the intra- and inter-tows regions
of the fibre mats with silica sol using electrophoretic deposition and (2) the fabrication of a composite by cold uniaxial
pressing and pressureless sintering of impregnated fibre mats sandwiched between layers of the matrix glass powder. The sintering
took place in air at 670°C, and composite materials of sufficient integrity could be obtained without damaging the fibres.
The deposited silica remained amorphous at the processing temperature providing a porous interface between the glass matrix
and the metallic reinforcement. Obervation of fracture surfaces revealed that both fibre pull-out and fibre deformation occur,
which should lead to a significant toughness enhancement. The presence of the interfacial silica layer, deposited using electrophoresis,
is thought to be responsible for this behaviour. 相似文献
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SiC晶须增韧陶瓷基复合材料及其分散研究 总被引:1,自引:0,他引:1
阐述了SiC晶须增韧陶瓷基复合材料的进展,指出晶须增韧过程中遇到的难题;综述了近年来对SiC晶须分散摘要并认为化学键合理论在SiC晶须的分散中是主性的研究及其效果,主要介绍了硅烷偶联剂的化学键合理论和物理作用理论,要的。 相似文献
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Metal matrix composites reinforced by three-dimensional (3-D) continuous network structure reinforcement (3DCNRMMC) are difficult to machine due to serious tool wear and poor surface roughness caused by the brittle and hard reinforcement which interpenetrate into ductile matrix. In order to achieve the approach of low cost of 3DCNRMMC, the machinability of it needs to be understood. The influences of three cutting parameters and volume fraction of reinforcement on cutting force were analyzed in detail. The results indicate that: (1) Due to the brittle phase(s) introduced into ductile matrix of composites, there is a large fluctuation of cutting force causing deterioration of machinability. The fluctuation ranges of cutting forces, initially increase rapidly with the increase of volume fraction of reinforcement and then decrease finally, are largest at the range of the volume fraction of 55–65%; (2) The influence of cutting parameters on cutting force is obvious. With the increases of cutting speed, cutting force decreases gradually unless cutting speed exceeds the value of 209 m/min. Cutting forces increase with increasing feed rate and depth of cut; (3) Owing to the large fluctuation of cutting force, there were some cratered surfaces caused by Si3N4 reinforcement pulling-out and flaking-off. Some brittle phase protruding from the machined surface caused the deterioration of machined surface. 相似文献
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先驱体转化法制备连续纤维增强陶瓷基复合材料的研究 总被引:6,自引:0,他引:6
综述了先驱体转化法制备连续纤维增强陶瓷基复合材料在先驱体、致密化工艺、微观结构、性能等方面的国内外研究情况 ,最后提出了今后进一步研究的方向 相似文献
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采用在线销钉集成技术实现了二维C_f/SiC复杂构件的近尺寸成型,并考察预氧化C_f/SiC销钉集成构件的高周疲劳寿命及破坏模式。实验结果表明:C_f/SiC构件在不同激振加速度条件下均表现为由销钉断裂所引起的整体分层破坏,层板连接处为C_f/SiC构件的振动疲劳薄弱部位。通过ANSYS振动应力分析和微观组织分析可以推论出,疲劳试验时,裂纹容易沿着层板间的基体扩展,在基体开裂失效后,全部应力施加于销钉处,最终在疲劳应力作用下销钉发生断裂,导致构件整体分层破坏。 相似文献
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Herein, few-layered graphene nanosheets (GNS) with approximately 3, 6, or 9 layers are used to reinforce high-performance nickel-based superalloy metal matrix composite. A powder metallurgy method comprising solution-mixing, hot isostatic pressing, and thermal processing is used to prepare GNS-FGH96 composites with different numbers of GNS layers as well as referential FGH96 matrix materials. Compared with those of unreinforced FGH96, the mechanical properties of the GNS-FGH96 composites are enhanced, specifically, the ≈6 layers GNS-FGH96 composite exhibits an ultimate tensile strength of 1660 MPa and a yield strength of 1229 MPa, which are 9.79% and 6.87% higher, respectively, than those without the addition of GNS. Furthermore, the ≈6 layers GNS-FGH96 composite exhibits the highest elongation-at-fracture of 29.9%. The as-prepared GNS-FGH96 composites show a good balance of strength and ductility owing to the increased dislocation density between the FGH96 matrix and GNS reinforcement interface area, as well as the high structural integrity of the GNS. Thus, this study provides a novel approach for designing and creating high-performance graphene-reinforced FGH96 metal matrix composites that exhibit exceptional strength and toughness. 相似文献
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通过叙述C/C和C/SiC两种复合材料的氧化特点分析了碳纤维增强陶瓷基复合材料(CFRCMCs)的氧化行为,分别从纤维、基体、界面层及外表面4个方面综述了碳纤维改性、基体抗氧化技术、界面层抗氧化技术和表面涂层技术4种CFRCMCs的抗氧化技术,分析了4类抗氧化技术的原理和特点。 相似文献
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