共查询到19条相似文献,搜索用时 140 毫秒
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综述了近年来碳化硅颗粒(SiCp)和碳化硅晶须(SiCw)增强铝基复合材料的发展,尤其是铝锂基复合材料的发展。SiC/Al复合材料的制造方法有铸造法、粉末冶金法、溅射沉积法等。碳化硅和铝的界面结合良好,由于碳化硅和铝的热膨胀系数相差六倍,因而在生产及热处理过程中收缩差所产生的错配应变会在基体中产生大量位错。人们认为,高密度的位错是SiC/Al强化的主要因素。 相似文献
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添加增强相可以提高铝基复合材料的力学性能,但同时也会促进界面上原电池网络的形成,从而提升铝基复合材料的腐蚀敏感性.因此,优化界面结构是改善复合材料耐腐蚀性能的重要途径.对此,我们提出固相铝热反应结合热处理的策略,在Al–CuO复合材料中构建包括晶界和增强体-基体界面在内的“素化界面”.本文通过浸渍/电化学腐蚀试验和微观结构表征系统研究了复合材料的晶间腐蚀行为和应力腐蚀开裂敏感性,强调了晶内分布纳米第二相(Al2O3增强相和Al–Cu沉淀相)对消除沿晶界连续原电池网络和阻断腐蚀路径的贡献.此外,研究发现具有低应变能且紧密结合的Al2O3–Al界面显著降低了局部腐蚀敏感性.这项工作阐明了复合材料界面特性与腐蚀机制之间的相关性,为发展耐腐蚀复合材料提供了新思路. 相似文献
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以常规TEM 为工具, 研究了SiCP/ ZL 109 复合材料中数十个SiC 颗粒及其界面,Si 优先在SiC 表面上形核、长大, 形成界面Si, 并形成大量SiC/S i 界面。靠近SiC 界面的Al 基体中, 普遍存在一层厚度小于1Lm 的“亚晶铝带”, 其内有大量位错。SiC 与Al、SiC 与Si 之间虽然没有固定的晶体学位向关系, 但是存在下列优先关系: (1103) SiC//(111)Al, [1120]SiC//[110]Al; (1101) SiC//(111) Si; [1120]SiC//[112]Si。 相似文献
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采用球磨-转喷微注相结合的新工艺制备纳米Al2O3颗粒(Al2O3p)/Al(7075)复合材料,设计一种转喷微注装置,该装置能将连续、微量的纳米Al2O3p注入到Al熔体中。观察纳米Al2O3增强相对Al(7075)基体合金材料微观组织的影响,并测试Al(7075)基体和纳米Al2O3p/Al(7075)复合材料的磨损特性。对纳米Al2O3p/Al(7075)复合材料和Al(7075)基体在不同载荷(15 N、25 N和35 N)下的磨损特性进行对比研究。结果表明:球磨-转喷微注法制备的纳米Al2O3p/Al(7075)复合材料晶粒较小,且增强相在基体中分布均匀且结合良好;随着载荷增大,纳米Al2O3p/Al(7075)复合材料磨损量的上升趋势慢于Al(7075)基体。载荷为35 N时,纳米Al2O3p/Al(7075)复合材料的磨损量较Al(7075)基体少,磨屑尺寸较小,其耐磨性能明显改善,这主要得益于纳米Al2O3p的支撑作用和材料的细晶强化作用。 相似文献
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《Composites》1990,21(2):127-131
Based on a simplified model of whisker reinforced metal matrix composite and by using the theory of the analytic function, the whisker rotation in the tensile process of the composite has been formulated. Through in-situ observation of a tensile process in SiC whisker reinforced aluminium (SiCw/Al) composite by a scanning electron microscope (SEM), the formula of the whisker rotation has been verified. Lastly the effect of the whisker rotation on the strength of SiCw/Al composite has been discussed. 相似文献
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The interface orientation relationships betweenSiC whiskers and matrix have been studied byX-ray diffraction and crystallite orientation distri-bution functions (CODFs) analysis.The distribu-tion of SiC whiskers in Al matrix of the as-castSiC_w/Al composite was nearly unperfect isotropic.Both matrix and SiC whisker in as-extrudedSiC_w/Al composite were〈111〉fiber texture.Itis suggested that there are certain interfaceorientation relationships between the SiC_w and theAl matrix. 相似文献
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Lin GENG Congkai YAO Dept.of Metals Technology Harbin Institute of Technology Harbin China 《材料科学技术学报》1993,9(6):431-436
The microstructure of SiC whisker reinforced aluminium alloy (SiC_w/Al) composite is reviewed,andthe SiC-Al interface in SiC_w/Al composite is especially discussed,The main contents aremorphology of the aluminium matrix in SiC_w/Al composite;microstructures and defects of SiCwhiskers in SiC_w/Al composite and bonding mechanisms of the SiC-Al interface in SiC_w/Al com-posite. 相似文献
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Mechanical, instrumented Charpy V-notch (CVN) energy and plane strain fracture toughness properties of SiC whisker reinforced-6061 aluminium metal matrix composite material from an extruded tube have been determined. The effect of thermal treatment and orientation have been studied. The mechanical strength properties are higher than wrought Al 6061 in the T6 condition. CVN energy values, however, were reduced by an order of magnitude.K
lc fracture toughness of the as-received, T6 and degassed + T6 thermal treatments were 50% of the wrought Al 6061 alloy. The effect of orientation showed that the orientation with the least amount of SiC whisker in the crack plane (i.e. greatest mean free path between reinforcements) yields the highest toughness value. 相似文献
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正挤压对SiCw/6061Al晶须形貌的影响 总被引:1,自引:0,他引:1
为了研究正挤压加工对SiCw/6061Al复合材料晶须形貌的影响规律,通过改变挤压温度、挤压比等工艺条件正挤压成形了挤压铸造法制备的15vol.%SiCw/6061Al复合材料,利用SEM技术观察和分析了正挤压加工前后复合材料的微观组织形貌.研究表明:正挤压加工导致SiC晶须沿着复合材料的塑性流动方向呈现出一定程度的定向排列趋势,并伴随有比较明显的折断现象;挤压温度、挤压比等工艺参数都是影响SiC晶须形貌的主要因素. 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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本文深入分析了用压铸法制造SiCw/Al复合材料过程中液态铝渗入SiC晶须预制块中的渗透过程。通过理论计算得到液态铝渗入晶须预制块的临界渗透压不超过2MPa。对不同晶须含量的预制块所进行的模拟渗透过程的压缩试验结果表明,随外力的增加,预制块被压缩的程度增大,从而使预制块的晶须相对含量增大。通过对渗透过程的分析,认为液态铝渗透晶须预制块需要一定时间,因此当外力以较大的速度达到最大值时,液态铝不能完全渗入预制块中,这时预制块将被压缩,导致所得复合材料晶须相对含量提高。研究结果表明,复合材料晶须体积分数主要取决于预制块晶须体积分数和复合压力。 相似文献
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Creep behavior in an Al-Fe-V-Si alloy and SiC whisker-reinforced Al-Fe-V-Si composite 总被引:1,自引:0,他引:1
L. M. PENG S. J. ZHU F. G. WANG H. R. CHEN Z. Y. MA J. BI 《Journal of Materials Science》1998,33(23):5643-5652
High temperature strengthening mechanisms in discontinuous metal matrix composites were examined by performing a close comparison between the creep behavior of 15vol. pct SiCw/8009Al and that of its matrix alloy, 8009Al. Both the alloy and composite exhibit a single-slope behavior with anomalously high values of apparent stress exponent and high apparent activation energy. The presence of SiC whiskers does not remarkably influence these two kinds of dependence of creep rates but reduces the creep rates by about two orders of magnitude. Transmission electron microscopy examination of the deformation microstructure reveals the occurrence of attractive dislocation/particle interaction. The creep data were analyzed by the threshold stress approach and by the dislocation-climb theories based on attractive interaction between dislocations and dispersoids. All data can be rationalized by a power-law with a stress exponent of 5 and a creep activation energy close to that for the self-diffusion in aluminum. The threshold stress decreases linearly with increasing temperature. General climb together with the attractive but not strong interactions between the dislocations and dispersoids is suggested to be the operative deformation mechanism. The contribution of SiC whiskers to the creep strength of 8009 Al composite can be evaluated quantitatively when the shear-lag model is applied. However, the effects of whisker length and whisker orientation distributions must be considered. Two probability density functions are used for modelling the distribution of whisker length and whisker orientation. 相似文献