芯片用金刚石增强金属基复合材料研究进展

随着电子设备集成化程度越来越高,对高导热封装材料的需求也越来越大,金刚石增强金属基复合材料凭借其高导热性能成为研究焦点。然而,由于金刚石颗粒与金属基体之间的不润湿特性,具有高导热性的金刚石增强金属基复合材料难以制备。文中综述了金刚石增强金属基复合材料的研究进展,包括界面改性、工艺参数优化和复合材料制备方法,并指出了金刚石增强金属基复合材料目前存在的问题和今后的研究方向。     

MWNTs/Fe_3Al金属间化合物基复合材料的导电性能

利用真空热压烧结和放电等离子体烧结两种方法制备了不同成分MWNTs/Fe3Al金属间化合物基复合材料;用透射电镜分析了复合材料的显微结构,并用微欧计测试了复合材料的电阻率后换算成电导率,研究了该复合材料的导电性能。结果表明:两种方法制备出复合材料的电导率随着碳纳米管含量的增加而降低;碳纳米管与金属间化合物相界面较高的势垒、纳米管的自身缺陷及其在基体中的分布方式影响了复合材料的导电性能。     

金属基复合材料差压浸渗凝固装置的设计

在分析金属基复合材料差压浸渗凝固原理的基础上设计差研制了新型金属基复合材料着压浸渗固装置，讨论充型压力、充型速度、预测件预热温度、浇注温度等工艺参数对铸造金属复合材料质量的影响。并指出各种参数值的选择范围。     

碳纳米管表面镀覆对碳纳米管-银复合材料性能的影响

研究了碳纳米管的表面镀覆处理对复合材料性能的影响，结果表明，碳纳米管经过化学镀银处理后用于制造复合材料，可以改善碳纳米管在金属基体中的分散性，提高复合材料的界面结合力，提高复合材料的硬度、导电性、抗弯强度。断口分析表明，碳纳米管未进行化学镀时，由于碳纳米管-银的弱界面结合，使碳纳米管拔出长度较长，在碳纳米管经化学镀后，由于改善了碳纳米管-银的界面结合状态，使碳纳米管拔出长度较短。     

颗粒增强金属基复合材料的制备进展

介绍颗粒增强金属基复合材料的常用制备工艺,分析各种制备方法的优缺点;论述对颗粒增强金属基复合材料制备技术研究的难点,并展望金属基复合材料的发展。     

利用铝热反应制备金属基复合物

本文研究了以铝热反应法制造金属基复合材料的方法、材料性能、这种复合材料其耐磨性高于基材合金，本方法不仅能制备铝基复合材料，还可制造熔点高于铝的其它金属复合材料。     

纤维增强金属基复合材料液相浸渗的关键工艺

通过对纤维预制体空隙的特性及金属液相浸渗充填过程的研究，获得了影响纤维增强金属基复合材料浸渗充填质量的主要因素，提出了获得高性能复合材料的途径。     

选区激光熔化制备金刚石/TC4复合材料的成型工艺及性能分析

针对金刚石/金属基复合材料在金属3D打印过程中致密化程度低的问题,采用了选区激光熔化技术成功制备金刚石/TC4复合材料,重点研究了金刚石/TC4复合材料的SLM打印工艺和性能。以提升金刚石/TC4复合材料致密度为目标,通过响应曲面分析法对SLM工艺参数进行优化和分析,初步建立了致密度数学模型,并通过模型预测参数组合优选值及最优致密度,对最优致密度成型件进行了抗弯强度测试,这对后续采用金属3D打印技术制备金刚石工具的有关研究具有重要的参考价值。     

金属基复合材料在微波封装领域的研究进展

电子信息技术的发展对封装材料的性能提出了苛刻的要求。金属基复合材料具有轻质、高导热、低膨胀等优异的热物性能,是一种理想的电子封装材料。电子封装用金属基复合材料增强体含量高,因而研制困难,工程应用的技术难度大。文中综述了国内外电子封装用金属基复合材料的性能及研究现状,指出了当前复合材料在应用中的主要问题,并针对这些问题给出了建议。     

颗粒增强金属基复合材料加工技术进展

颗粒增强金属基复合材料具有优良的物理力学性能,但材料的难加工特性限制了其应用。因此,对颗粒增强金属基复合材料加工技术的研究与发展是促进其进一步应用的关键之一。本文从加工方法、加工质量等方面综述了国内外颗粒增强金属基复合材料加工技术的进展情况,并指出了当前存在的问题及解决对策。     

Complementary TEM characterization of a squeeze-cast metal-matrix composite by dissolution of the sample in butanol

Transmission electron microscopy observations of ion-beam thinned samples and samples extracted using a butanol dissolution technique gave information regarding the interface microstructure which could not be obtained from the ion-beam thinned samples, and that therefore both these sample preparation routes should be considered when observing aluminium metal-matrix composites in the transmission electron microscope.     

波形碳纳米管增强复合材料的有效刚度和局部应力的宏微观均质化数值模拟

采用分子动力学方法简化的碳纳米管等效纤维模型,利用具有精确周期性边界条件的均质化理论和宏微观均质化法分析正弦波形非连续碳纳米管的有效刚度和局部应力分布规律.结果表明,纳米增强复合材料的有效刚度和局部应力对碳纳米管的波形非常敏感,碳纳米管稍有弯曲就会导致复合材料有效刚度降低和应力传递能力的下降,为揭示复合材料中碳纳米管的增强机制和改善增强效果提供理论依据.     

Microstructural observations of reaction zones in Ti-based metal-matrix composites

The interaction between Ti-alloy matrices and ceramic particulate and fibres in Ti-based metal-matrix composites (MMCs) is reviewed. It is concluded that the stability of surface-treated SiC fibres is adequate for some applications of MMCs, but no other fibres have yet been developed which are useful additions to Ti alloys. Although there is less interest at this stage in particulate-reinforced Ti MMCs, there are two ways in which useful particulate MMCs could be developed. First, the approach used in fibre-reinforced composites, of using special coating techniques to stabilize the particulate against any reaction with the matrix. Second, either C or B additions could be used, both of which give rise to particulate phases which are stable in the presence of a Ti matrix, and which can therefore be manufactured using a wider range of process routes than is possible for other composites. The significance of these conclusions with regard to the ability to shape particulate composites into final products is briefly discussed.     

Microstructure and fracture behaviour of particle-reinforced metal–matrix composites

The fracture behaviour of particle-reinforced metal-matrix composites is shown to be controlled by a period of damage nucleation and evolution prior to final failure. The nucleation of damage can be by reinforcement fracture or decohesion and the mode of damage is shown to be controlled by the size of the reinforcement and segregation of alloying elements from the matrix. The nucleation and growth of damage can be monitored by a number of techniques. Acoustic emission and tomography are used here and the results are found to be consistent with simple models of void growth.     

复合轧制氧化铝-铝基复合材料工艺与界面结合机制

通过6061铝合金双板复合轧制成功制备内含微弧氧化陶瓷颗粒的新型复合板,为金属基复合材料制备开辟一条新途径。用撕裂法测试复合板的结合强度结果表明：铝板前处理、轧制温度和压下率都对该复合板的结合强度(决定复合材料力学性能的重要指标)有明显的影响,并在本试验温度范围内结合强度出现了极大值。由温度因素研究得知,与裂口机制和镶嵌机制相关的回复再结晶软化、金属原子动能升高和氧化隔离3个次级机制存在于本试验研究条件下,并且由温度因素影响它们的主导作用地位。在轧制过程中微弧氧化铝合金表面陶瓷层破裂形成的陶瓷颗粒,使双板构成镶嵌结合关系。     

Effect of turning parameters on surface roughness of A356/5% SiC composite produced by electromagnetic stir casting

In the present investigation, A356 alloy 5 wt% SiC composite is fabricated by electromagnetic stir casting process. An attempt has been made to investigate the effect of CNC lathe process parameters like cutting speed, depth of cut, and feed rate on surface roughness during machining of A356 alloy 5 wt% SiC particulate metal-matrix composites in dry condition. Response surface methodology (Box Behnken Method) is chosen to design the experiments. The results reveal that cutting speed increases surface roughness decreases, whereas depth of cut and feed increase surface roughness increase. Optimum values of speed (190 m/min), feed (0.14 mm/rev) and depth of cut (0.20 mm) during turning of A356 alloy 5 wt% SiC composites to minimize the surface roughness (3.15μm) have been find out. The mechanical properties of A356 alloy 5 wt% SiC were also analyzed.     

Influence of surfactants on tribological behaviors of MWCNTs (multi-walled carbon nano-tubes)

Multi-Walled Carbon Nano-Tubes (MWCNTs) are employed as anti-wear and anti-friction additives in mineral oil. The MWCNTs are known for their superior thermal conductivity, mechanical and optical properties. It is expected that hollow-core carbon nano-tubes provide easy sliding as well as rotating action with respect to one another; therefore, there is a need to explore the use of MWCNT as lubricant additive. In the present research work, experimental investigations have been conducted to explore the importance of the MWCNTs as additives in the lubricating oils. Tests were performed on three oil samples: Sample 1 (Base oil), Sample 2 (MWCNT with base oil) and Sample 3 (MWCNT and surfactant with base oil), by employing block on disc set-up. To understand the role of surfactant on MWCNT towards reducing the friction and wear, sensitivity analysis performed using fractional factorial table has been detailed. The results of cumulative wear and friction have been reported in this study.     

三维编织碳/碳复合材料(C/C)的拉伸性能及损伤

C/C复合材料具有优异的高温性能 ,采用编织结构可改善其受外载时的内部应力状态 ,提高力学性能。但是 ,三维编织 C/C复合材料结构、组织的多样性 ,加大了其性能及损伤研究的难度。本文主要研究了三维编织 C/C复合材料的拉伸性能及损伤扩展过程 ,分析了影响性能的主要因素 ,并总结了材料的损伤破坏方式     

MACHINABILITY OF AI/SiC PARTICULATE METAL-MATRIX COMPOSITES UNDER DRY CONDITIONS WITH CVD DIAMOND-COATED CARBIDE TOOLS

This article investigates the machinability of two Al/SiC particulate metal-matrix composites (MMC) with 5 and 15% vol. SiC particles. Dry turning tests were performed with three different CVD diamond-coated tools. In a first series of experiments, various cutting conditions were tested and their effects on tool wear mechanisms were studied. For the second series, optimal cutting conditions were chosen and tool life was investigated. The consumed spindle power was continuously measured; it was shown that its increasing follows the evolution of the tool wear criteria. Residual stresses at the machined surfaces were measured by X-ray diffraction technique. The effect of SiC percentage in the MMC on the machinability was also investigated.