外加颗粒增强表层复合材料制备方法

按照采用热源和陶瓷增强颗粒的添加方式,对外加颗粒增强表层复合材料的制备方法分类.详细介绍了堆焊、激光熔覆、激光熔射、等离子熔化-注射等颗粒增强表层复合材料的制备方法,并分析了各种制备技术的优缺点.堆焊特点是基体与表层为冶金结合,效率高.激光熔覆可以实现输入的准确控制,冷却速度快,热畸变小.但是堆焊和激光熔覆过程都存在裂纹问题.激光熔射不受基体可焊性限制,可制备颗粒增强相连续分布的表层,避免裂纹的形成.等离子熔化-注射技术与激光熔射技术类似,可以制备出增强相体积分数从0～100%连续变化的梯度复合材料.避免由于增强颗粒分布不均引起的裂纹,实现低投入、低成本运行.     

Effect of particle characteristics on deformation of particle reinforced metal matrix composites

The particle characteristics of 15% SiC particles reinforced metal matrix composites (MMC) made by powder metallurgy route were studied by using a statistical method. In the analysis, the approach for estimation of the characteristics of particles was presented. The study was carried out by using the mathematic software MATLAB to calculate the area and perimeter of each particle, in which the image processing technique was employed. Based on the calculations, the sizes and shape factors of each particle were investigated respectively. Additionally, the finite element model (FEM) was established on the basis of the actual microstructure. The contour plots of von Mises effective stress and strain in matrix and particles were presented in calculations for considering the influence of microstructure on the deformation behavior of MMC. Moreover, the contour maps of the maximum stress of particles and the maximum plastic strain of matrix in the vicinity of particles were introduced respectively.     

Developments in the non-traditional machining of particle reinforced metal matrix composites

The non-traditional machining of particulate reinforced metal matrix composites is relatively new. However, researchers seem to pay more attention in this field recently as the traditional machining of particulate reinforced metal matrix composites is very complex. This research investigates different non-traditional machining, such as electro-discharge, laser beam, abrasive water jet, electro-chemical and electro-chemical discharge machining of this composite materials. The machining mechanism, material removal rate/machining speed and surface finish have been analysed for every machining process. This analysis clearly shows that vaporisation, melting, chemical dissolution and mechanical erosion are the main material removal mechanisms during non-traditional machining. The thermal degradation and the presence of reinforcement particles mainly damage the machined surface. The understanding of electro-discharge, laser beam and abrasive water jet machining is more developed than that of electro-chemical and electro-chemical discharge machining for particulate reinforced MMC.     

用钛酸钡陶瓷颗粒制备金属基复合材料

介绍了金属基复合材料用钛酸钡陶瓷的结构及性能,并重点阐述了制取钛酸钡的常用方法,总结了这些方法的优点和需要改进的地方,展望了钛酸钡作为金属基复合材料强韧化相的研究动向.     

离心铸造WC颗粒增强钢基复合材料辊环的研制

介绍了WCp/钢基复合材料轧辊的材料选择和制备工艺 ,并对其显微组织及力学性能进行了分析。工业实验结果表明 :复合材料轧辊的寿命比普通Cr12轧辊高 3倍以上     

铝金属基复合材料表面稀土转化膜

介绍了铝金属基复合材料的发展情况及存在的腐蚀问题,详细评述了铝金属基复合材料表面稀土转化膜在国内外的研究进展及现状,对未来这一技术的发展提出了展望。     

Fabrication and abrasive wear properties of metal matrix composites reinforced with three-dimensional network structure

1. Introduction Metal matrix composites (MMCs) have some re- inforcements such as particle, whisker, and fiber [1-3] as well as the three-dimensional network structure [4]. In recent years, metal matrix compos- ites reinforced with three-dimensional network structure (3DNRMMCs) have been paid consider- able attention, since they possess a rather high spe- cific strength, stiffness, and wear-resistance and can be attractive candidates for structural and functional materials [5]. There are s…     

激光焊接颗粒增强铝基复合材料中TiB2颗粒的演变行为（英文）

研究大功率激光器焊接TiB2颗粒增强铝基复合材料时TiB2粒子的演变行为。采用X射线衍射(XRD)、扫描电镜(SEM)及能谱(EDS)分析焊缝内粒子的物相、热力学过程及形貌特征;同时对TiB2和铝基体的界面反应进行讨论。结果表明:当TiB2团簇尺寸大于激光光斑直径时,焊缝中部的TiB2粒子会熔融在一起,较大尺寸的TiB2会发生断裂;当与铝熔体接触后,熔化后的TiB2粒子会与Al发生反应生成Al3Ti和AlB12,并且焊缝中部的界面反应比焊缝边缘的剧烈。     

SiC颗粒增强铝基复合材料的连接现状

SiC颗粒增强铝基复合材料因其具有成本低、耐磨性好、高比强度和比刚度、高谐振频率等优良的性能受到关注,但由于难于机械加工,特别是焊接性较差制约其在工程中的应用推广. 文中通过对国内外SiC颗粒增强铝基复合材料的连接现状(焊接方法主要集中于熔化焊、扩散焊、搅拌摩擦焊和钎焊等)进行综述和评价. 结果表明,SiC颗粒和Al基体的较大物理化学性能差异是影响该种复合材料焊接性的主要因素;当SiC颗粒体积分数低于35%时,目前已取得令人基本满意的焊接效果,已具有小批量生产的趋势;但当SiC颗粒体积分数大于35%时,特别是针对高体积分数(55% ~ 75%)的复合材料而言,传统的熔化焊方法很难获得高质量的接头,因此选择合适的连接方法和特殊的焊料成分则成为该种材料的重要创新方向.     

金属基复合材料的分类及制造技术研究进展

研究金属基复合新材料是当代新材料技术领域中的重要内容之一.金属基复合材料具有高比强度、高比模量、较好的耐热性和更低的热膨胀系数等优点,针对金属基复合材料的制备工艺不完善、成本高、难形成大规模的生产等弱点,并结合国内外相关工作的研究状况,从金属基复合材料的分类、性能特点以及制成品的制备技术与应用方面,对其领域内取得的研究...     

Microstructure of in-situ TiC particle reinforced titanium alloy matrix composites

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｉｔａｎｉｕｍｍａｔｒｉｘｃｏｍｐｏｓｉｔｅｓａｒｅｉｎｔｅｒｅｓｔｉｎｇｆｏｒｈｉｇｈｔｅｍｐｅｒａｔｕｒｅａｎｄｈｉｇｈｓｔｒｅｎｇｔｈａｐｐｌｉｃａｔｉｏｎ .Ｕｓｕ ａｌｌｙ ,ｍａｔｒｉｃｅｓａｒｅｒｅｉｎｆｏｒｃｅｄｂｙｃｏｎｔｉｎｕｏｕｓｓｉｌｉｃｏｎｃａｒ ｂｉｄｅｆｉｌａｍｅｎｔｓ .Ｔｈｒｅｅｍａｉｎｐｒｏｂｌｅｍｓｈａｖｅｂｅｅｎｉｄｅｎ ｔｉｆｉｅｄｉｎＳｉＣ/Ｔｉｃｏｍｐｏｓｉｔｅｓｍａｔｅｒｉａｌｓ :( 1)ｕｎｓｔａｂｉｌｉｔｙｂｅｔｗｅｅｎｔｈｅｆ…     

Tribological stability of particle reinforced aluminum matrix composites in braking

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｔｒａｎｓｐｏｒｔｍａｃｈｉｎｅ ,ｓｕｃｈａｓａｕｔｏｍｏｂｉｌｅ ,ｔｒａｉｎａｎｄ ｐｌａｎｅｉｎｔｅｎｄｓｔｏｂｅｃｏｍｅｈｉｇｈ ｓｐｅｅｄａｎｄｌｉｇｈｔｅｒｏｎｅ ,ｂｕｔｔｈｅｒｅｌａｔｉｖｅｈｅａｖｙｂｒａｋｉｎｇｅｑｕｉｐｍｅｎｔｃｏｎｆｉｎｅｓｉｔｓｄｅｖｅｌｏｐｍｅｎｔ .Ｔｈｅｔｒａｄｉｔｉｏｎａｌｂｒａｋｅｄｉｓｋ ,ｗｈｉｃｈｉｓｍａｎｕｆａｃｔｕｒｅｄｂｙｃａｓｔｉｒｏｎ ,ｎｏｔｏｎｌｙｈａｓａｈｉｇｈｄｅｎｓｉｔｙ ,ｂｕｔａｌｓｏｍａｉｎｔ…     

改善颗粒增强金属基复合材料塑性和韧性的途径与机制

评述了影响颗粒增强金属基复合材料塑性和韧性的各种因素,在此基础上深入研究了颗粒形状对ＳｉＣｐ／ＬＤ２复合材料塑性和断裂韧性的影响规律。采用有限单元法分析不同形状的ＳｉＣ颗粒增强的ＬＤ２复合材料的微区力学环境和整体力学行为,结果表明颗粒的尖锐化导致基体内应变集中和颗粒尖端断裂的可能性加剧,因而降低材料的塑性;而在外加载荷的作用下,由于复合材料基体整体均处于较高的加工硬化状态,因此颗粒形状对材料断裂韧     

Structure formation during processing short carbon fiber- reinforced aluminum alloy matrix composites

Nickel- and copper-coated, as well as uncoated, short carbon fibers were dispersed in melts of aluminum or aluminum alloys by stirring followed by solidification of composite melts. Microstructural examina-tion of cast composites indicated extensive damage to the surface of the carbon fibers when uncoated carbon fibers were introduced into the melt under the conditions of the present investigation. When nickel- or copper-coated carbon fibers were used to make composites under similar conditions, the fibers generally did not exhibit observable amounts of fiber surface degradation at the interface, except for small islands of an Al₄C₃ phase. When nickel-coated carbon fibers were used to make composites, the coating reacted with the melt, and NiAl₃ intermetallic phase particles were observed in the matrix away from the fibers, indicating a preference for nucleation of NiAl₃ away from the fiber surfaces. Under a transmission electron microscope (TEM), the NiAl₃ phase was not observed on the surface of carbon fi-bers, except in some regions where the NiAl₃ phase engulfed the carbon fibers during growth. When cop-per-coated carbon fibers were used to make composites, the coating reacted with the melt, and particles of CuAl₂ intermetallic compound were generally dispersed in the matrix away from the fibers, except for a few locations where the CuAl₂ phase was found at the interface under TEM observation. These micro-structures are discussed in terms of nucleation of primary α aluminum and NiAl₃ or CuAl₂ phases and the interaction between short carbon fibers and these phases during growth while the composite was so-lidifying. Additionally, the role of the reaction between nickel or copper coatings and the melt on struc-ture formation is discussed; some of the differences between the nickel and copper coatings are attributed to the fact that nickel dissolves with an exothermic reaction. The differences between solidification of short fiber composites and particle or fiber composite are also discussed.     

Effect of particle cracking on the strength and ductility of Al-SiCp powder metallurgy metal matrix composites

The effects of particle cracking on the strength and ductility of Al-SiCp metal matrix composite material (MMC) was investigated. The composite was manufactured using a simple powder metallurgy (PM) technique of hot pressing followed by hot extrusion. Also, the effects of reinforcement weight fraction and strain rate variations on the strength and ductility of the same composite were examined. It was found that particle cracking plays a significant role in controlling the mechanical properties of the composite. It was shown that particle cracking is possible in an MMC material made with a low strength matrix (commercially pure aluminum), and increases with the increase of reinforcement weight fraction, applied strain rate, and amount of plastic deformation. The yield strength increases as a function of reinforcement weight fraction and to a lesser extent as the strain rate increases. The tensile strength increases at low SiCp weight fractions, then remains constant or decreases as more particles are added to the matrix.     

钢纤维增强有色金属基复合材料综述

有色金属基复合材料相对于传统有色金属材料而言,具有更好的抗氧化性、高耐热性、高比强度、高比模量、耐磨损和高使用寿命。在有色金属基复合材料的众多的增强体中,非金属纤维(C/C、SiC)与金属基质结合界面的相容性是制约金属基复合材料性能的关键问题,而金属纤维与金属基质之间良好的相容性能够有效改善金属材料的性能。金属纤维增强有色金属基复合材料的制备工艺主要有扩散粘结法、液态渗透法、压力铸造法、涂层热压法、双辊轧制法。 本文主要总结了钢纤维增强有色金属基(Al、Mg、Cu、Zn和Zr)复合材料的制备方法、微观组织、界面特征和机械性能,指出了钢纤维增强有色金属基复合材料进一步研究发展所需要解决的问题。     

高速磨削颗粒增强钛基复合材料的热分配分析

针对颗粒增强钛基复合材料(PTMCs)高速磨削的特征,以均匀热源为模型,提出了一种计算磨削过程中热分配比例的新方法。采用CBN超硬磨料砂轮在80~160m/s的速度范围内进行了高速磨削验证,试验结果表明:PTMCs高速磨削热传递过程中比能es与ds1/4ap-3/4vw-1/2呈直线关系,与理论分析相一致,并基于此得到电镀CBN砂轮高速磨削PTMCs进入工件的热量比例为52.0%~79.5%。同时,进行了电镀砂轮高速磨削PTMCs温度场仿真,探明了其温度分布特征。     

金属基复合材料制备工艺的研究进展

系统论述了金属基复合材料研究和发展的概况,简要介绍了金属基复合材料的常用金属基体、增强体,重点阐述了金属基复合材料常用的制备技术,即：搅拌铸造法、粉末冶金法、原位生成法等。另外,对金属基复合材料的润湿性、界面反应、复合材料力学性能和有限元模拟作了简单介绍。最后,对半固态成形技术应用于金属纂复合材料中的成形加工发展方向做了展望。     

Modeling of the consolidation of continuous- fiber metal matrix composites via foil- fiber- foil techniques

The consolidation of metal-matrix composites (MMC) via hot isostatic pressing (HIP) of foil-fiber-foil layups has been investigated using finite element method (FEM) metal flow analysis. For this purpose, the deformation pattern for various fiber arrangements was determined using representative unit cells to describe extremes in behavior. For a given fiber architecture, the consolidation time was found to be heavily dependent on the ratio of the HIP pressure to average flow stress and the friction conditions at the matrix-fiber interface. The specific influence of material properties such as the rate sensitivity of the flow stress appears to enter only as a second order effect. The FEM solutions were used to construct HIP diagrams delineating temperature-time-pressure combinations for full composite consolidation. Laboratory trials on subscale foil-fiber coupons were used to validate the FEM predictions.     

Microstructures and wear resistance of large WC particles reinforced surface metal matrix composites produced by plasma melt injection

Large WC particles (− 840 μm-+ 420 μm) reinforced surface metal matrix composites (SMMCs) were produced using plasma melt injection (PMI) process on a Q235 (similar to ASTM A570 Gr. A) low carbon steel substrate. Microstructures of the SMMC were observed using scanning electron microscope (SEM), and the composition was determined with energy dispersion spectroscopy (EDS). Phases were analyzed with X-ray diffraction. Micro-hardness of the SMMC was tested. Wear losses of the SMMC layer were evaluated under dry friction conditions and compared with those of the substrate material. The results show that the large WC particles are caught by crystallized metal and stay in the upper part of the SMMC layer, and there is only a little melting on the outer surface. No sinking down of WC particles occurs. The SMMC layer is well bonded to the substrate, and the interface is crack free. The wear resistance of the Q235 substrate is greatly improved with large WC particles injected.