高阻尼铝基复合材料在海水中的腐蚀行为

研究了高阻尼铝基复合材料在海水中的腐蚀行为,本实验所用高阻尼铝基复合材料是以6061铝合金为基体,加入SiC颗粒和石墨粉,用粉末冶金方法制备的。测定了高阻尼铝基复合材料在海水中的腐蚀速率度、电极电位和极化曲线,并通过与基体金属的对比来描述它的腐蚀特性。实验表明,在海水介质中,高阻尼铝基复合材料的耐蚀性能比6061铝合金差,孔蚀倾向大。在海水介质中使用高阻尼铝基复合材料必须加以保护。     

碳化硅颗粒增强铝基复合材料的发展概况

概述了碳化硅颗粒增强铝基复合材料（ＳｉＣｐ／Ａｌ）的制备工艺、性能和应用。     

高阻尼金属基复合材料的发展途径

在综述传统高阻尼金属材料和金属基复合材料的阻尼特性的基础上，探讨获得高阻尼性能的金属基复合材料的途径，指出采用高阻尼的基体合金，采用高阻尼的增强物以及设计高阻尼的界面层是效的三种方法，为发展密度更小同时又集结构与阻尼功能于一体的新型材料提供了可能。     

高阻尼金属基复合材料的发展途径

在综述传统的高阻尼金属材料和金属基复合材料阻尼的特性的基础上，探讨获得高阻尼性能金属基复合材料的途径。     

铝金属基复合材料的腐蚀研究进展

综述了不同增强体增强的铝金属基复合材料（Al MMCs)的腐蚀研究现状，包括腐蚀机制、腐蚀形貌、影响腐蚀的因素以及发展趋势。     

SiCp和Al2SiO5f混杂增强纯镁的阻尼性能

制备了以混杂碳化硅颗粒和硅酸铝短纤维为增强物，以纯镁为基体的金属基复合材料。     

高阻尼金属基复合材料的发展途径

本文在综述传统的高阻尼金属材料和金属基复合材料的阻尼特性基础上，探讨获得高阻尼金属基复合材料的途径，指出采用高阻尼的基体合金、采用高阻尼的增强体以及设计高阻尼的界面层是三种有效方法，为发展密度更小同时又兼有优良机械性能和阻尼功能的新型金属基复合材料提供了可能。     

空心陶瓷／铝基复合材料的阻尼减振性能

采用挤压铸造法制备了70%（体积分数）空心陶瓷/6061Al复合材料．采用弯曲共振法测试了复合材抖的阻尼性能，结果表明．空心陶瓷的加科明显提高了6061Al合金的阻尼性能，且尺寸减小会进一步提高空心陶瓷复合材料的阻尼性能。采用弯曲共振法测得的含较小粒径的空心陶瓷/6061Al复合材料的阻尼为基体6061Al阻尼的5.7倍，这表明空心陶瓷／6061Al复合材料阻尼与材料内部所含孔洞有密切的关系。结各组织观察，本文对相关的阻尼机理进行了探讨。     

高强度阻尼铝基复合材料研究

基于多相结构阻尼原理,根据阻尼混合原则,通过激冷金属基体提高其阻尼行为的同时添加合理的合金元素、具有不同截面滑动能耗的增强相以及改变增强相的体积分数,采用高速小漩涡剪切搅拌制备的混杂颗粒增强铝基复合材料,既获得高的比强度和比刚度同时,也有优异的阻尼性能,实现了在不降低A356性能的同时,开发出一种以A356为基的低密度高强度高阻尼结构-功能一体化的新型结构材料。     

空心陶瓷/铝基复合材料的阻尼减振性能

采用挤压铸造法制备了70%(体积分数)空心陶瓷/6061Al复合材料,采用弯曲共振法测试了复合材料的阻尼性能.结果表明,空心陶瓷的加入明显提高了6061Al合金的阻尼性能,且尺寸减小会进一步提高空心陶瓷复合材料的阻尼性能.采用弯曲共振法测得的含较小粒径的空心陶瓷/6061Al复合材料的阻尼为基体6061Al阻尼的5.7倍,这表明空心陶瓷/6061Al复合材料阻尼与材料内部所含孔洞有密切的关系.结合组织观察,本文对相关的阻尼机理进行了探讨.     

Powder metallurgy of Al-based composites reinforced with Fe-based glassy particles: Effect of microstructural modification

Al metal matrix composites reinforced with high volume fraction of Fe_50.1Co_35.1Nb_7.7B_4.3Si_2.8 glassy particles were fabricated by mechanical milling followed by hot pressing. Elemental Al powders blended with 60 vol.% of glassy particles were mechanically milled for 1, 5, 10, 15, and 20?h, respectively. Selected samples were sintered by uniaxial hot pressing under Ar atmosphere. The changes in the microstructure along with their mechanical properties were investigated. Structural and microstructural characterization followed by microhardness and compression test results of the bulk composite material is reported. The use of high volume fraction of Fe-based glassy particles as reinforcement led to significant hardening of the Al matrix while leading to a remarkable combination of high strength and plasticity.     

低密度高阻尼金属/金属复合材料

采用快速凝固 /粉末冶金法制备了Al-7Fe -1 .4Mo -1 .4Si(FMS0 71 4)合金及其复合材料FMS0 71 4/xAl(x=1 0～ 2 0 )和FMS0 71 4/y(Zn-3 0Al) (y =1 0～ 2 0 )w(B) / % .运用三点弯曲法、拉伸试验和阿基米德法分别测试了其阻尼性能、拉伸性能和密度 .结果表明 :FMS0 71 4合金本身即具有较好的阻尼性能 .添加纯Al粉对其阻尼性能影响不大 ;而添加Zn-3 0Al合金粉则显著提高其阻尼性能 .FMS0 71 4合金及其复合材料的阻尼性能与拉伸强度均优于LD7CS合金 .其中 ,FMS0 71 4/ 1 5 (Zn-3 0Al)具有最佳的综合性能 ,在航空和航天领域显示出良好的应用前景 .     

高阻尼空心微珠/环氧复合材料的制备及性能研究

制得不同粒径空心微珠/环氧复合材料,并对其进行断口形貌、阻尼性能和耐热性进行了研究.其阻尼性能的测试是采用动态力学热分析仪,通过拉伸-压缩的方法在不同变温(-40～150℃)和变频(10～800Hz)条件下完成的.结果表明相同条件下,添加过筛100～140目空心微珠的复合材料在玻璃化转变温度(Tg)下的阻尼性能相对较好(tanδmax=0.892),并且随频率增加损耗因子衰减较慢.通过复合材料断口的扫描观察发现空心微珠均匀分布在基体中,且与基体的结合较好;通过热重测试发现空心微珠概率粒径越大,复合材料耐热性越好.     

Deformation at ambient and high temperature of in situ Laves phases-ferrite composites

The mechanical behavior of a Fe₈₀Zr₁₀Cr₁₀ alloy has been studied at ambient and high temperature. This Fe₈₀Zr₁₀Cr₁₀ alloy, whoose microstructure is formed by alternate lamellae of Laves phase and ferrite, constitutes a very simple example of an in situ CMA phase composite. The role of the Laves phase type was investigated in a previous study while the present work focuses on the influence of the microstructure length scale owing to a series of alloys cast at different cooling rates that display microstructures with Laves phase lamellae width ranging from ～50 nm to ～150 nm. Room temperature compression tests have revealed a very high strength (up to 2 GPa) combined with a very high ductility (up to 35%). Both strength and ductility increase with reduction of the lamella width. High temperature compression tests have shown that a high strength (900 MPa) is maintained up to 873 K. Microstructural study of the deformed samples suggests that the confinement of dislocations in the ferrite lamellae is responsible for strengthening at both ambient and high temperature. The microstructure scale in addition to CMA phase structural features stands then as a key parameter for optimization of mechanical properties of CMA in situ composites.     

Advances in the fabrication of titanium based composites

Titanium alloy metal matrix composites reinforced with silicon carbide fibre are being evaluated for a range of highly loaded aerospace applications. Although expensive, if used selectively they can have a dramatic effect on performance and weight. The SMC has one of the strongest capabilities in Europe for the development and production of titanium fibre reinforced MMCs. Consisting of the DRA Sigma silicon carbide fibre manufacturing facility, producing fibre on a commercial basis, and the manufacture of titanium alloy MMCs in commercial quantities by the foil fibre route, and at pilot scale using the alternative matrix coated fibre route. In the foil fibre route a filament winding and fugitive binder method is used to produce a range of component shapes with excellent fibre distribution and consistent properties. The matrix coated fibre process is seen to have advantages over the alternative methods and is likely to become an important manufacturing route for titanium MMCs, particularly for exotic high temperature titanium alloys and intermetallics, and for shapes such as rings, tubes and shafts. As no titanium MMCs components have yet reached full production, it is unclear which of these fabrication methods will become commercially viable, if any. But, the choice is likely to be based on cost, availability and product quality.     

A study of continuous filament reinforced aluminum matrix composites

Some principal results of the research work on metal matrix composites at Beijing Institute of Aeronautical Materials, concerning CVD-produced continuous B and SiC filaments reinforced aluminum and its alloys, are summarized. The processing, fiber degradation, interface, mechanical properties and fracture behavior of the composites are discussed.Abbreviations CVD chemical vapor deposition - MMCs metal matrix composites - ROM rule of mixtures     

高能超声处理对原位Al3Ti/A356复合材料显微组织和力学性能的影响

采用熔体直接反应法,以工业钛剂和A356合金为反应物,利用高能超声原位合成了Al3Ti/A356复合材料。利用X射线衍射与扫描电镜对该复合材料的微观组织和物相组成进行分析,并通过拉伸实验对该复合材料的力学性能进行测试。结果表明,经过高能超声处理后,复合材料中的Al3Ti颗粒尺寸较高能超声处理前明显变小,分布也更均匀。当超声功率为1.2kW/cm2,超声作用时间为360s时,颗粒尺寸最小,为0.5～2μm。复合材料的抗拉强度、屈服强度和伸长率分别达到281.83、226.72MPa和5.6%,较未施加高能超声的复合材料分别提高了16.2%、10.3%和33.3%。     

Analysis on effect of electroless coated SiCp on mechanical properties of polymer matrix composites

ABSTRACT

The versatility of polymer matrix composites in industrial applications has gained reputation and adaptability among advanced materials. Still, treatment of reinforcement for these composites has emerged as a vital domain to be explored. With a continuance to this fact, the present paper aims to analyze the effect of reinforced electroless coated silicon carbide particulates on mechanical properties of composites. The composite is developed using epoxy polymer as matrix and glass fibers as primary reinforcement. The electroless coated and uncoated silicon carbide particulates were used as secondary reinforcement. The phase identification of copper on secondary reinforcement was identified using X-ray powder diffraction technique. Fracture analysis during tensile testing and bonding behavior between matrix and reinforcement is examined using field emission scanning electron microscopy with energy dispersive spectroscopy. The presence of copper particles on secondary reinforcement results in improved interfacial bonding and resistance against fracture during loading.     

热处理对粉末热挤压法制备6061铝合金强度和塑性的影响

研究了单级固溶及峰值时效处理对粉末热挤压法制备6061铝合金显微组织及室温力学性能的影响,观察了合金挤压态、固溶态及时效处理后的显微组织,并对其力学性能进行了测试.结果表明:挤压态材料的晶粒均匀细小,基体合金中存在大量的第二相颗粒,主要为Mg2Si相;热挤压后的6061铝合金经固溶时效处理(530℃×1 h水冷+170℃×6 h)后,晶粒内部析出大量的β″(Mg5Si6)相,并伴有少量棒状的β’(Mg2Si)相析出,拉伸强度和延伸率分别为311 MPa和10%,相比挤压态铝合金,其拉伸强度提高了近160%.