石墨烯金属基复合材研究进展

本文详细叙述了石墨烯及其衍生物等增强相的应用范畴及适用区别以及比较了金属基复合材料的不同制备方法,分析传统的制备方法之间的分类特点及应用方向,重点提出了工艺步骤灵活、可控性极高的新型制备石墨烯增强金属基复合材料的方法—激光增材制造技术。深入讨论了石墨烯及其衍生物作为增强相,给金属基复合材料中带来的力学、摩擦学、电学、金属耐腐蚀等性能方面的改变,比较了石墨烯及衍生物作为增强相对铝、镁、镍、铜、钛等金属基复合材料性能提高及改善程度和在不同金属基复合材料中仍存在的增强相各种团聚、分散问题与金属基体的界面结合等及目前提出的处理方案,最后提出制备石墨烯金属基复合材料未来发展方向及新型制备技术仍存在的实际问题。     

Al-C纤维复合材料微结构钎焊连接

金属基复合材料中应用的金属材料（Ｍｇ，Ａｌ，Ｔｉ及其合金等）与增强组元（碳纤维，ＳｉＣ晶须，颗粒等）的物理，化学，力学性能相差极大，将它们复合成一整体作为结构材料使用，成为当今材料科学内极为重要的新领域。从焊接学科角度，对复合材料内部存在的结构异质材料的连接技术加，偿查对复合材料力学性以及复合工艺有直重要意义，对复合材料（板，榛，管等）实用化时，它与其它材料的焊接也有实际意义。     

金属粉末注射成形的工艺研究与应用

介绍了金属粉末注射成形工艺的应用,制备工艺的现状与发展,特别介绍了这项工艺在枪械零件等相关领域的开发与应用。通过对工艺流程的解析,介绍了国外同行生产的同类产品和国内产品的应用。通过应用实例,介绍了国产金属材料采用蜡基材料的可行性,以及采用国内工艺装备实现的工艺过程。     

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…     

金属粉末注射成型制备血管支架的实验动物生物相容性

通过临床动物实验评价金属注射成型(MIM)制备的新型血管支架的可行性与安全性.采用粉末注射成型技术制备血管支架,大幅提高材料利用率;研究MIM过程中碳杂质含量变化对316L不锈钢力学性能与耐腐蚀性能的影响;同时开展MIM血管支架的体外毒性测试与动物实验以评价支架的安全性.结果表明,316L不锈钢的性能对碳含量变化极为敏...     

Reheating process of metal matrix composites for thixoforming and their inductive coil design

In this work, the fabrication processes of particulate metal matrix composites (PMMCs) with a homogeneous distribution of reinforcement and their reheating for thixoforming were studied. Electromagnetic stirring was used to fabricate PMMCs to vary particle size. PMMCs were tested before and after the reheating process using a tensile test with and without heat treatment. The combined process conditions for fabricating the PMMCs are also suggested for a variety of particle sizes. For the thixoforming of PMMCs, fabricated billets are reheated by using an induction heating system with a maximum capacity of 20 kW. The effects of the dispersion state of the reinforcements on the reheating temperature and microstructural morphology were investigated.     

An analysis of the tensile elongation to failure of laminated metal composites in the presence of strain-rate hardening

We extend the analysis of Hutchinson and Neale (Hutchinson JW, Neale KW. Acta Metall 1977;25:839) and Ghosh (Ghosh AK. Acta Metall 1977;25:1413) predicting the tensile elongation to failure of strain-rate-dependent plastic materials to two-phase composites deforming quasistatically according to the equistrain rule of mixtures. The analysis incorporates the influence of work hardening and strain-rate hardening in both composite constituent phases. It is shown that the problem can be formulated in a manner that condenses the seven underlying material parameters into four dimensionless numbers for composites of power-law hardening phases, the number of parameters falling to two for linear hardening. It then emerges that the stabilizing influence of both work hardening and strain-rate hardening is, within assumptions of the model, always predominantly exerted by the phase that carries the greater share of the composite stress. It is also shown that the prediction can be simplified so as to enable an approximate but convenient direct graphical deduction of the tensile elongation of ductile laminated metal composites (LMCs), knowing the work hardening and strain-rate hardening characteristics of the two phases making the composite. The utility of this graphical scheme is illustrated with two examples, namely LMCs containing one phase of (moderately ductile) aluminium alloy or of a (low-ductility) nanocrystalline metal.     

一种新型液态金属浸渗网络结构预制体制备复合材料装置的设计

根据机械设计理论和液压知识，开发和设计了一种制备网络结构陶瓷增强金属基复合材料的新型装置。利用油缸液压和真空负压，成功实现了液态金属的浸渗。     

Study of metal injection molding of highly porous titanium by physical modeling and direct experiments

The prospects of metal injection molding (MIM) technique for manufacturing of highly porous titanium parts was studied by physical modeling, based on feedstock warm compaction experiments. The space holder method and typical MIM binder were used in all cases of the study. The influence of the starting powder (dehydrided and atomized) in feedstock on resulting properties of porous titanium was investigated. The size of space holder particles and space holder amount were adjusted to obtain porosity and pore size desired for medical implants application. NaCl and KCl were studied and compared as prospective space holder materials. The porous samples were characterized regarding their microstructure, uptake of interstitial contents and mechanical properties. For comparison, same investigations have been conducted on samples, which were prepared by established space holder technology based on cold isostatic pressing (CIP) and sintering. Finally, first direct MIM experiments and attempts of feedstock optimization were carried out. The peculiarities and problems of metal injection molding of highly porous titanium have been discussed.     

硅酸铝短纤维增强AZ91复合材料的制备

以晶化的硅酸铝短纤维为增强体，以偏磷酸铝为粘结剂，把干法和湿法结合起来制做预制块，采用挤压浸渗工艺制备AZ91镁基复合材料，结合光学显微镜和扫描电镜进行铸造缺陷和显微组织分析。结果表明，中性的磷酸铝溶液是制备硅酸铝短纤维增强镁基复合材料（Al2O3-SiO2/AZ91）的最合适的预制块用粘结剂之一；采用复合挤压工艺可以有效防止或减轻金属基复合材料的组织缩松。     

工艺参数对金属注射成形坯缺陷的影响

采用ＭＩＭ标准拉伸试样模具,研究注射过程主要工艺参数即注射温度,注射压力,模具温度对注射过程缺陷的影响,获得了最佳注射工艺参数,对欠注,断裂,中心通孔等几种缺陷的形成机制作了分析,并提出了ＭＩＭ成形范围图的概念。     

金属注射成形喂料的流动行为及粘度参数的测定

从材料的综合流动曲线及聚合物、粘结剂的流动性能，分析了金属注射成形喂料的流动行为，给出了用毛细管粘度计测量金属注射成形喂料粘度并确定其流动曲线参数的分析方法。     

Surface topography and cytocompatibility of metal injection molded Ti–22Nb alloy as biomaterial

Metal injection molding (MIM) was applied to fabricating Ti–22Nb (mass fraction, %) and commercially-pure Ti (CP-Ti, selected as reference) discs. As references, arc-melted and polished Ti–22Nb discs were employed. The surface topography and cytocompatibility were comparatively assessed on each configuration by microscopic analysis using confocal laser scanning microscopy and scanning electron microscopy and adhesion and viability tests. The results reveal that micron-scale roughness could be obtained via MIM process, and using blended Ti and Nb elemental powders instead of only Ti powder as raw materials leads to much higher surface roughness and surface area ratio. None of the three materials shows cytotoxicity, and the adhesion of human primary cells seems to be increased on the MIM Ti–22Nb specimens, especially around the closed-pores on the surface.     

SiCf增强Ti-48Al-1.5Mn复合材料的界面反应

利用透射电子显微镜（TEM）对SiC纤维（SiCf)增强Ti-48Al-1.5Mn复合材料的界面区域进行了分析。结果表明，在材料的复合过程中，SiCf与γ－TiAl基体之间发生了化学反应，形成了TiC1-x,Ti5Si3和Ti2AlC等一系列产物，并对这些产物的形成机制进行了分析。在高温条件下，C，Si原子从纤维向基体扩散和Ti,Al,Mn等原子从基体向纤维扩散，发生了界面反应。     

金属注射成形技术进展

分析了影响金属注射成形（ＭＩＭ）产业化进程的两个主要技术因素，即适合ＭＩＭ要求的原料粉末的生产方法和ＭＩＭ生产工艺，并概述了目前ＭＩＭ技术的发展状况。     

Ultrafast densification and microstructure evolution of in situ Ti/TiB metal matrix composite obtained by PPS approach

The newly methods of material production based on electrical pulse utilised for metal matrix composites preparation, interest and attracts due to possibilities of sintering of a wide range of materials to high densities in a short time period at relatively low temperatures. Advantages of this approach allow avoiding the grain growth and lead to more precise control of final material properties also by the starting precursor choice. Morphology, grain size and purity of precursor, connected with it physical properties and chemical composition that is next submitted to the process parameters could reveal subtle dependence in microstructure and densification mechanism in obtained composite sinters. Ultrafast electric pulse consolidation allows to obtained the in situ Ti/TiB metal matrix composites due to reaction mechanism kinetics, focusing however on heating rate and energy availability. Specific heating conditions for Pulse Plasma Sintering process used to consolidate the precursor material with a high-current pulse approach correlate with final obtained properties.     

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。     

注射成形铜/钨复合材料溶剂脱脂行为研究

以注射成形铜/钨复合材料生坯为研究对象,采用二氯甲烷为溶剂,对成分为CuW5以及CuW15的两种成分的生坯,采用不同粉末装载量、不同形状的试样进行溶剂脱脂。重点考察了溶剂脱脂工艺参数对脱脂行为的影响,还就坯件本征特点对于溶剂脱脂行为的影响进行了分析探讨,最后计算了本实验条件下,用二氯甲烷脱脂的动力学参数,为后续实验条件的设定提供了理论依据。实验结果显示,脱脂温度与时间对于溶剂脱脂是综合外因;在研究脱脂行为时,考虑坯件本体特征的影响十分重要,坯件厚度对于溶剂脱脂影响很大,形状的复杂性几乎不影响脱脂率。粉末形态不够规则,生坯内部孔隙多,溶剂脱脂更易持续进行,达到更大的脱脂量。脱脂初期脱脂速率由扩散控制,呈线性变化,当脱脂时间达到10h以后,脱脂速率将转变为由溶解和扩散混合控制。     

金属注射成型(MIM)综合脱脂炉的结构设计特点

介绍了金属注射成型(MIM)综合脱脂炉的结构设计特点,该设计可同时满足包括溶剂、催化、冷凝蒸汽、虹吸脱脂在内的脱脂工艺要求.     

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.