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液态浸渗是制造纤维增强金属基复合材料的先进工艺。本文根据热力学原理对金属粹浸渗纤维空隙过程进行了研究,发现纤维分布、基体金属液相对纤维的润湿性和外加压力是影响浸渗过程的主要因素,找到了控制浸渗过程、获得高质量纤维增强金属基复合材料的工艺途径。 相似文献
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浸渗压力对金属基复合材料液相浸渗过程的影响 总被引:2,自引:0,他引:2
液态浸渗法是制造纤维增强金属基复合材料的先进工艺。本文根据热力学原理对金属液浸渗纤维空隙过程进行了研究,发现纤维分布、基体金属液对纤维的润湿性和外加压力是影响浸渗过程的主要因素,找到了控制浸渗过程、获得高质量纤维增强金属基复合材料的工艺途径。 相似文献
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浸渗法制备ZTA陶瓷颗粒增强铁基复合材料的研究取得了很大进展。针对陶瓷预制体制备,铁水对陶瓷预制体的浸渗,陶瓷与铁水的润湿性,复合材料界面结合,复合材料耐磨性等方面的研究进行了论述。解决铁水对预制体的润湿性是实现浸渗的先决条件,常用的方法有在陶瓷预制体中添加活性元素,通过化学镀、气相沉积以及包覆等方法对陶瓷表面进行改性等;在陶瓷与金属基体间形成过渡层可以改善结合界面的组织结构,促进陶瓷与金属基体形成冶金结合;铁水对陶瓷预制体的浸渗机理,以及ZTA陶瓷复合材料的耐磨机理尚需要深入研究。 相似文献
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低浸渗压力制备纤维增强铝基复合材料 总被引:2,自引:0,他引:2
利用液态浸渗技术制备了氧化铝纤维增强铝基复合材料。研究结果表明,在低压下使液态合金浸渗纤维预制件制备铝基复合材料是可行的。在浸渗过程中,液态合金的温度对浸渗压力有较大影响。所制备的复合材料具有均匀的显微组织,基体中的共晶组织可依附在纤维表面形核生长。 相似文献
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采用小颗粒TiC包覆SiC陶瓷颗粒,在惰性气体保护下选用无压浸渗方法制备了高铬铸铁/TiC-SiC复合材料;利用SEM/EDX观察和分析了液态铸铁在SiC预制体中的浸渗情况、组织特征和成分分布;结合高铬铸铁/Ti-SiC复合材料的组织特点和浸渗行为特点,分析了TiC粉体对浸渗行为和复合材料组织的影响。观察结果表明,当TiC加入量≤10%(质量分数,下同)时,Fe/Cr合金无法润湿SiC颗粒,而当加入量≥20%时,Fe/Cr合金和预制体之间润湿性得到改善,增加TiC含量更有利于Fe/Cr合金浸渗;基体中大尺寸SiC颗粒消失,出现了尺寸接近毫米级的条状单质碳,这与高铬铸铁/Ti-SiC复合材料的组织差异较大。对比两种复合材料组织发现,添加Ti粉末在金属液中可与C结合生成TiC,而添加的TiC颗粒在组织中呈鹅卵石状,边缘圆润,出现金属液与陶瓷颗粒之间的互溶。在浸渗过程中,添加TiC和Ti与浸渗金属发生的反应不同,且高质量分数的TiC对金属液浸渗过程有明显的促进作用。 相似文献
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采用"中断浸渗"方法获得保留了"浸渗前沿"的样品,应用扫描电子显微镜和X射线能谱分析了浸渗界面上的形貌和成分变化,深入讨论了浸渗界面推进过程中的物理、化学反应过程.采用扫描电镜等微观分析手段观察了复合材料显微形貌,探讨了界面反应机理.研究结果表明:浸渗界面推进过程中熔体中的Mg富集在浸渗前沿的预制体上,并与预制体发生反应;Al/Si3N4界面反应产物AlN相形成"楔形"向Si3N4单元心部推进,细观上呈现含毛细通道的胞状辐射形貌,大量毛细通道确保了Al和Si3N4之间的置换反应持续进行;Al与Si3N4的置换反应产物Si绝大部分溶解在铝镁合金熔体中. 相似文献
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DETERMINATIONOFTHRESHOLDPRESSUREFORINFILTRATIONOFLIQUIDALUMINIUMINTOSHORTALUMINAFIBERPREFORM¥HuLianxi;LuoShoujing;HuoWencan(S... 相似文献
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Tingting Liu Xinbo He Qian Liu Lin Zhang Ling Wang Qiping Kang Xuanhui Qu 《Journal of Materials Engineering and Performance》2013,22(6):1649-1654
Starch-based and paraffin wax (PW)-based binders were used to fabricate short graphite fiber preforms for liquid metal infiltration. The effects of different binder components and debinding process parameters on the properties of short graphite fiber preforms were investigated. The results indicate that the graphite fiber preforms with appropriate porosity of 58-62% and relatively high compressive strength of about 2-3 MPa can be made by starch-based and PW-based binders. The graphite fiber preforms made from the PW-based binder exhibit higher compressive strength than that of the starch-based binder. Graphite fiber reinforced aluminum composites fabricated by utilizing these preforms through vacuum pressure infiltration have relatively high density of 98.5% and thermal conductivity of 186.3 W/m K, proving the applicability of the prepared preforms for liquid metal infiltration. 相似文献
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A new method for determining two key parameters (threshold pressure and permeability) for fabricating metal matrix composites was proposed based on the equation-solving method. An infiltration experimental device was devised to measure the infiltration behavior precisely with controllable infiltration velocity. Two experiments with alloy Pb-Sn infiltrating into Al2O3 preform were conducted independently under two different pressures so as to get two different infiltration curves. Two sets of coefficients which are functions of threshold pressure and permeability can be obtained through curve fitting method. By solving the two-variable equation set, two unknown variables were determined. It is shown that the determined threshold pressure and permeability are very close to the calculated ones and are also verified by another independent infiltration experiment. The proposed method is also feasible to determine the key infiltration parameters for other metal matrix composite systems. 相似文献
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Chao Chen Hong Guo Ke Chu Fazhang Yin Ximing Zhang Yuanyuan Han Yeming Fan 《稀有金属(英文版)》2011,30(4):408-413
The thermal conductivity of diamond/copper composites with bimodal particle sizes was studied.The composites were prepared through pressure infiltration of liquid copper into diamond preforms with a mixture of 40 and 100 μm-size diamonds.The permeability of the preforms with different coarse-to-fine volume ratios of diamonds was investigated.The thermal conductivity of the diamond/copper composites with bimodal size distribution was compared to the theoretical value derived from an analytical model developed by Chu.It is predicted that the diamond/copper composites could reach a higher thermal conductivity and their surface roughness could be improved by applying bimodal diamond particle sizes. 相似文献
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D. T. Kountouras C. A. Vogiatzis F. Stergioudi A. Tsouknidas S. M. Skolianos 《Journal of Materials Engineering and Performance》2014,23(6):2015-2019
In this paper, a methodology to optimize the production technique and properties of fly ash porous preforms, for liquid metal infiltration, is introduced. The preforms were produced by mixing fly ash with acid phosphate binder and acetone as liquid carrier, at varying compositions. The homogeneity of the green product was determined by micro computed tomography (μCT) and scanning electron microscopy. The effect of binder quantity, porosity, and compaction pressure of the preforms on the resulting bending strength was investigated and considered as one of the criterions for the production of crack-free metal matrix composites (MMCs). Finally the quality of the MMCs, resulting by liquid metal infiltration of the optimized preforms, was examined by μCT to locate micro cracks and uniaxial compression to determine variations in their compressive strength. 相似文献
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以铸造碳化钨颗粒(Cast Tungsten Carbide Particle,CTCP)与还原铁粉为原料,采用松装烧结工艺制备具有蜂巢状结构的多孔陶瓷预制体;通过铸渗法制备了CTCP/Cr26铁基表层复合材料;采用扫描电镜、X射线衍射仪、电子探针等手段分析了预制体和复合材料的显微组织。结果表明:高温烧结过程中还原铁粉中的Fe与CTCP中的W2C发生反应,在CTCP表面形成了烧结壳层,壳层内侧的物相组成为WC+Fe3W3C,壳层外侧的物相是Fe3W3C;壳层相互连接使预制体具有较高强度,铸渗过程中高强度的预制体能够抵抗高温液态金属的热冲击,从而保证了复合材料中预制体的蜂巢状结构;制备的复合材料中CTCp与金属基体的界面形成明显的过渡层,过渡层的物相组成为WC+Fe3W3C,过渡层的形成是烧结壳层在高温金属液中发生溶解与析出的结果。 相似文献
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Effect of specific pressure on fabrication of 2D-Cf/Al composite by vacuum and pressure infiltration
Carbon fiber reinforced aluminum matrix (Cf/Al) composite has many excellent properties, and it has received more and more attention. Two-dimensional (2D) Cf/Al composites were fabricated by vacuum and pressure infiltration, which was an integrated technique and could provide high vacuum and high infiltration pressure. The effect of specific pressure on the infiltration quality of the obtained composites was comparatively evaluated through microstructure observation. The experimental results show that satisfied Cf/Al composites could be fabricated at the specific pressure of 75 MPa. In this case, the preform was infiltrated much more completely by aluminum alloy liquid, and the residual porosity was seldom found. It is found that the ultimate tensile strength of the obtained Cf/Al composite reached maximum at the specific pressure of 75 MPa, which was improved by 138.9% compared with that of matrix alloy. 相似文献
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低压浸渗法制备Gr(C)/Mg复合材料 总被引:2,自引:0,他引:2
对用低压浸渗法制备石墨(碳)长纤维镁基复合材料进行了研究。结果表明,制备工艺条件对复合状况、界面反应及复合材料性能均有明显影响。通过纤维表面SiO2涂层处理和优化浸渗工艺,可成功地制备出高性能的复合材料,拉伸断裂强度可达509MPa,模量亦可达142GPa。 相似文献