钼铜材料制备技术研究进展

Mo/Cu复合材料作为一种假合金,同时具备了钼的低膨胀系数和铜的高导热特性,而且,其热膨胀系数和导电导热系数可以通过调节钼铜比例加以设计,这使得Mo/Cu复合材料被广泛应用于电子封装、热沉材料、大规模集成电路器件及相关领域中。目前,电子信息技术向微型化、大容量、高可靠性方向的发展,对Mo/Cu复合材料的热电性能提出了更加苛刻的要求,这同时也促进了Mo/Cu复合材料制备技术的不断创新与发展。     

高导热金属基复合材料的制备与研究进展

随着电子器件芯片功率的不断提高,对散热材料的热物理性能提出了更高的要求.将高导热、低膨胀的增强相和高导热的金属进行复合得到的金属基复合材料,能够兼顾高的热导率和可调控的热膨胀系数,是理想的散热材料.本文对以Si、SiCp、金刚石、鳞片石墨为增强相的铜基及铝基复合材料的研究进展进行了总结,并就金属基复合材料目前存在的问题...     

轻质Si-Al电子封装材料制备工艺的研究

探讨采用传统粉末冶金方法制备轻质、高性能Si-50％Al(质量分数，下同)电子封装材料的可能性。研究了粉末粒度组成、压制压力、烧结温度对材料室温导热性和室温到200℃间热膨胀系数的影响。发现采用一定的粉末粒度组成，高压制压力、高温和适当的时间烧结能够获得综合性能较好的Si-Al复合材料。     

W-Cu(Mo-Cu)复合材料的研究进展

W-Cu或Mo-Cu两相复合材料具有较高的导热性和较低的热膨胀系数,在大功率器件中被视为一种很好的热沉材料。近年来,有关W-Cu或Mo-Cu作为电子热沉材料的研究在国内外已有一些报道。作者主要就近几年钨铜复合材料研究的几个主要热点问题进行综述报道。分析认为,梯度结构功能材料、纳米结构材料以及注射成形工艺在钨铜复合材料领域中的应用是当今钨铜电子材料发展的主要方向,同时对国内外最新研究进行了归纳总结,指出了今后发展的主要动向。     

Comparison of the Wear Properties of Polymer Composites Having CNT With and Without Glass Fiber Reinforcement

The adoption of light weight and high performance polymer matrix composites are needed for industries related to aerospace, automotive, consumer goods, etc. Polymer fiber reinforced composite material have very good desirable mechanical and thermal properties like low density, higher specific stiffness with high specific strength and a controlled co-efficient of thermal expansion with dimensional stability. The addition of carbon nanoparticle in these composites improved mechanical as well as wear properties of the material, which leads to more applications of these composites in various fields. In the present investigation carbon nanotube addition along with the glass fiber reinforced composite material was used as work material. The sliding wear tests were carried out on pin on disc wear tester. The tribological performance was studied by varying the applied load. The wear surfaces were analyzed by using scanning electron microscope, X-ray diffraction and energy-dispersive X-ray spectroscopy which are presented in detail.     

热解碳结构对炭/炭复合材料摩擦磨损性能的影响

通过控制化学气相沉积(CVD)工艺条件,得到粗糙层、光滑层、过渡层等几种具有不同微观结构的热解碳。金相观察、摩擦磨损性能的测试结果表明:热解碳的微观结构对炭/炭复合材料的摩擦磨损性能有重大影响;粗糙层结构的炭/炭复合材料摩擦因数高,热稳定性好,是一种优良的摩擦材料;光滑层结构的炭/炭复合材料摩擦因数低,磨损小,可以用作耐磨材料。     

热压ZrCp/W复合材料的热物理性能

采用热压工艺制备了ZrCp/W系列复合材料，分析测试了温度和ZrC含量对复合材料的热物理性能的影响规律。结果表明：随着温度的升高，复合材料的比定压热容和平均线膨胀系数单调增大，热导率略有增大。随ZrC含量的增加，复合材料的比定压热容和平均线膨胀系数线性增大，基本满足混合定律。热导率对材料的组织结构比较敏感，随ZrC含量的增加而急剧减小。热导率的实测值大大低于理论计算值，这主要是由晶界和孔洞等缺陷对导热粒子的强烈散射作用造成的。     

Cu/Al复合材料界面组织与性能的研究进展

Cu/Al复合材料拥有优异的导电、导热性能及良好的耐腐蚀性，被广泛应用于通讯、电力和新能源等领域。作为异种金属连接形成的复合材料，其在制备过程中最大的难点在于消除异种金属间热膨胀系数差异等物理性质引起的缺陷，且连接处的界面间组织是影响其性能的主要因素，所以对此进行研究十分重要。综述了超声波焊接、搅拌摩擦焊、爆炸焊和铸造法下Cu/Al复合材料界面金属间化合物（IMC）的种类、形成机理，同时总结了Cu/Al复合材料性能改进常用的辅助手段：在等离子焊接和真空铸造工艺中添加微量元素；在拉拔旋压、轧制和爆炸焊后进行热处理；在超声波焊接、轧制中进行电脉冲辅助。国内外研究者们还广泛应用计算机模拟技术来研究Cu/Al复合材料的界面组织和性能。采用自主研发的冲击射流复合铸造工艺成功制备出Cu/Al复合材料，界面组织为Al2 Cu， AlCu和Al4Cu9，最大结合强度为23 MPa。     

Thermal conductivity and thermal expansion of graphite fiber-reinforced copper matrix composites

The high specific conductivity of graphite fiber/copper matrix (Gr/Cu) composites offers great potential for high heat flux structures operating at elevated temperatures. To determine the feasibility of applying Gr/Cu composites to high heat flux structures, composite plates were fabricated using unidirectional and cross-plied pitch-based P-100 graphite fibers in a pure copper matrix. Thermal conductivity of the composites was measured from room temperature to 1073 K, and thermal expansion was measured from room temperature to 1050 K. The longitudinal thermal conductivity, parallel to the fiber direction, was comparable to pure copper. The transverse thermal conductivity, normal to the fiber direction, was less than that of pure copper and decreased with increasing fiber content. The longitudinal thermal expansion decreased with increasing fiber content. The transverse thermal expansion was greater than pure copper and nearly independent of fiber content. formerly with NASA Lewis Research Center, is retired David L. McDanels, This article is based on a presentation made in the symposium “High Performance Copper-Base Materials” as part of the 1991 TMS Annual Meeting, February 17–21, 1991, New Orleans, LA, under the auspices of the TMS Structural Materials Committee.     

烧绿石结构A_2B_2O_7热障涂层材料热物理性能综述

烧绿石结构材料由于具有良好的高温相结构稳定性,低热导率等优点,是最为广泛研究且最具有应用前景的新型热障涂层材料系列之一。本文从烧绿石结构材料高温相稳定性、热导率、热膨胀系数、断裂韧性、抗烧结性、与Al2O3化学相容性等几个方面进行了综述,并将成分和掺杂对各性能的影响规律进行了归纳和总结,对新型烧绿石结构热障涂层材料的成分设计、性能研究等具有重要意义。     

Mo—Cu合金的研究进展

Mo—Cu合金具有高的导热系数和低的线膨胀系数,被广泛应用于电触头材料、热沉材料、电子封装材料等。本文介绍了Mo—Cu合金的制备方法,以及提高Mo—Cu合金的致密化的方法,指出了Mo—Cu合金现在存在的问题及发展趋势。     

高热导率低热膨胀系数Cu-ZrW_2O_8复合材料的制备与性能

以负热膨胀材料ZrW2O8与金属Cu为原料,分别采用常规烧结法和热压法制备具有高热导率低膨胀系数的新型Cu基复合材料Cu-ZrW2O8,研究ZrW2O8体积分数与烧结方法对该复合材料致密度、热导率及热膨胀系数的影响.结果表明:热压法制备的Cu-50%ZrW2O8复合材料的热导率达173.3 W/(m·K),致密度为91.6%,均明显高于常规烧结样品;热压样品的热膨胀系数为11.2×10-6K-1,稍高于常规烧结样品:在150～300℃温度范围内热处理后该样品的平均热膨胀系数降低到10.87×10 -6K-1,较纯Cu的平均热膨胀系数17×10-6K-1低很多,有望成为一种新型的电子封装材料.     

Investigation into thermalphysic properties and thermal stability of shell molds based on quartz sand and ash of thermoelectropower stations for a foundry using dispensable patterns

The quartz mold, which has low thermalphysic and thermal properties, is the main source of waste in a foundry using dispensable patterns. Therefore, it is necessary to fabricate shell molds from an alternative material with smaller linear expansion and higher thermal conductivity. An analysis of the thermalphysic properties and thermal stability of the molds shows that ceramic shells in which the ash from thermoelectropower stations is used as the dusting are most thermally stable, and they can be recommended for pouring without a support material. Since ash from thermoelectropower stations is production waste, this can significantly affect the cost of shell molds, which is especially topical due to the ongoing economic crisis.     

Fabrication,microstructures and properties of 50 vol.-% SiCp/6061Al composites via a pressureless sintering technique

Commercial F500 SiC powder and 6061 Al powder were chosen to fabricate the 50?vol.-% SiCp/6061Al composites via pressureless sintering. Effects of pre-treatment of the SiC powder and sintering temperature on the microstructures and properties of the composites were studied. Densification mechanism and interfacial reaction of the composites were also investigated. The results show that the composites have a high sintering ability and a low interfacial reaction activity. The density, bending strength and thermal conductivity of the composites are all sensitive to the sintering temperature. The composites sintered at 680°C are nearly fully dense and have the following optimal properties: the relative density of 98.5%, the bending strength of 495?MPa, the TC of 153?W/(m?K) and the coefficient of thermal expansion of 8.1?×?10^?6/°C (50–100°C), which are superior to most of the SiCp/Al composites of the similar composition reported previously.     

原位合成颗粒增强铜基复合材料的研究进展

弥散强化型铜基复合材料,兼具优异的导电导热性能、高强度、良好的热稳定性和耐磨性,是核反应堆、航空器及高端装备中各种导电导热元件的关键材料,在核电、航空、交通、军事等诸多重要领域有不可替代的作用。原位合成法是在一定温度下金属基体内发生化学反应,原位生成一种或几种陶瓷增强体的技术。原位反应制备颗粒增强铜基复合材料存在两个重要的问题亟待解决：一是增强相的团聚问题,二是增强相的尺寸调控问题。本文总结了几种较为常用的制备弥散强化型铜基复合材料的原位合成方法,并对比分析了几种方法的特点、优劣及技术难点。同时,本文综述了原位合成法对铜基复合材料中颗粒尺寸和分布的影响,分析了原位合成法不同参数对复合材料力学及综合性能的影响规律,并从增强相颗粒形核与生长的原理出发,提出了促成细小弥散颗粒增强相的工艺方案。     

渗铜用钨骨架制备工艺的研究进展

钨铜复合材料结合了钨的高熔点、高硬度、低膨胀系数和铜的高导电、导热性能,是一种性能十分优良的复合材料。熔渗法是目前制备钨-铜材料中广泛应用的方法,而熔渗法制备钨铜材料的关键是怎样获得一定致密度的钨骨架。目前制备钨骨架常用的方法主要有以下4种：（1）高温烧结;（2）模压成形;（3）挤压成形;（4）注射成形。本文就目前这4种常用钨骨架的制备工艺进行了简要的介绍和评述。     

泡沫铝及其复合材料的研究进展

泡沫金属是一种由金属基体和气孔组成的新型结构功能材料,相对于实体金属材料,泡沫金属材料以牺牲了强度等力学性能为代价,获得了诸如热、声、能量吸收、轻质等优越性能,成为一种新型结构功能材料。泡沫铝是一种在铝基体中形成很多气孔的轻质多孔金属材料,同时兼有金属和气泡特征,它密度小、耐高温、防火性能强、抗腐蚀、隔音降噪、导热率低、电磁屏蔽性高、耐候性强、有过滤能力、渗透性好,具有良好的阻尼特性和电磁屏蔽能力,广泛应用在冶金、化工、航空航天、船舶、电子、汽车制造和建筑业等领域。对泡沫铝制备方法和物理性能的研究有利于提高其性能、扩大其应用领域,本文概述了泡沫铝的制备方法、物理性能及增强泡沫铝基复合材料的研究进展。     

Mo-15Cu制备过程分析与控制

对钼铜金属基复合材料的熔渗机理、熔渗过程进行了详细的分析,并以制造Mo-15Cu复合材料为例,对其制备方法的选择及关键工艺参数的优化进行了试验。试验表明:在还原性气氛下,采用粉末预处理、高压压制钼骨架、熔渗烧结等工艺流程是制备高致密度的低膨胀、高导热钼铜金属基复合材料的有效可行的途径。笔者还就各工艺参数对材料性能的影响进行了探讨。     

MMCX—An expert system for metal matrix composite selection and design

Metal Matrix Composites (MMCs) are a relatively new class of engineering materials that offer the designer an opportunity to tailor properties to meet specific requirements. The paper summarizes the development of an expert system which supports engineers in the selection and design of metal matrix composites. The system consists of a dynamic hypertext interface integrated into an expert system developed within the COMDALE/X environment. Mechanical and thermophysical property data for matrix alloys, reinforcement materials, and MMCs are stored in databases accessed by the expert system. Mathematical models which utilize constituent material properties to determine effective composite properties are managed by the system to design metal matrix composites and fill property gaps. Effective elastic modulus, thermal conductivity, coefficient of thermal expansion. Poisson's ratio, shear and bulk moduli mathematical models for particulate, whisker, short fiber and fiber composites are contained in a spread sheet managed by the system. Although the physical and mechanical properties may often limit the constituent selection, it is the chemical reactivity of the ceramic reinforcement with the matrix alloy either during fabrication or service which will generally control the final matrix/reinforcement combination. As a result, constituent material compatibility has been determined and incorporated in the system. A database of appropriate reinforcement coatings for applicable matrix/reinforcement systems is also helpful. The system also includes information on suitable manufacturing techniques. A case study demonstrating the use of the system for selecting an MMC for cryogenic applications is presented.     

基于线性规划算法的磷生铁最优化成分设计

铝电解槽阳极组装用磷生铁在使用过程中需要的特性与其本体材料的物理性能息息相关。运用材料热力学的方法计算出五大元素(C,Si,P,Mn,S)的含量变化对磷生铁电导率和热膨胀系数的影响,并通过线性回归建立电导率和热膨胀系数与五大元素含量和温度的函数关系,最后利用线性规划最优化算法对某铝厂现行磷生铁成分进行有目的性的优化。通过优化后,磷生铁电导率最大优化率为14.50%,热膨胀系数最大优化率为5.99%。