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原位金属基复合材料的制备原理及工艺 总被引:6,自引:0,他引:6
简述了原位自生增强体金属基复合材料的制备原理及工艺。基于热力学和动力学原理,讨论了自生增强体的形成机制,展望了这种新型复合材料的工业应用前景。 相似文献
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离心铸造复合材料的研究与发展 总被引:5,自引:0,他引:5
综述了离心铸造复合材料的发展概况和研究现状,提出了铸造人工复合材料和铸造自生笔合材料分类的新观点,指出了离心铸造复合材料研究中存在的问题。 相似文献
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自生复合材料由于其相与相之间无润湿、化学反应等问题,因此其有独特的优点。本文简要介绍了自生复合材料的理论、制备及研究现状和展望。 相似文献
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从自生TiC颗粒增强钛基复合材料(PTMCs)的制备方法、微观组织及界面结构、性能和应用与展望4个方面论述了自生TiC颗粒增强钛基复合材料的研究进展。重点介绍了近年来PTMCs的一些制备方法及在室温、高温时的力学性能。 相似文献
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制备共晶自生复合材料的生产效率低、增强相体积分数调节范围小等因素极大地制约了共晶自生复合材料的发展和商业应用。采用 LMC 和电子束区熔两种高温度梯度定向凝固装置,不但提高了自生复合材料的生产效率,而且还扩大了增强相体积分数的调节范围。在 LMC 高温度梯度定向凝固条件下,凝固速率在7.14μm/s 范围内,偏离共晶成分2.9wt%Ni-Nb 亚共晶合金都可制备出片层状共晶自生复合材料。生长速率平方根的倒数与共晶片层间距具有线性对应关系,该系统有λ~2R=83.14μm~3/s 的关系式。Ni-TaC 系共晶自生复合材料中 TaC 纤维体积分数在一定范围内随凝固速率而改变。其中,Ni—TaC16复合材料中 TaC 纤维间距和凝固速率的函数关系为λ=13.18R~(-0.4972),横向面积与凝固速率的函数关系为 S=-0.6597R+5.14。Ni-TaC 系复合材料中 TaC 和基体相的界面结构一般为规则的折线状。同时,还发现了不规则的折线界面形貌、波浪线形界面形貌和鱼骨状界面形貌。纤维状的共晶 TaC 以金字塔方式定向生长,形成规则排列的 TaC 纤维。共晶 TaC 横向边缘不稳定性和生长速率的各向异性决定了共晶 TaC 横向截面的多样性。Ni-TaC16共晶自生复合材料拉伸性能,随着纤维体积分数的增大而显著提高。室温和高温的形变强化特征决定了复合材料常温和高温的拉仲断裂模式。 相似文献
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钢管混凝土组合柱轴心受压承载力计算方法 总被引:1,自引:0,他引:1
简要介绍了钢管混凝土组合柱轴心受压承载力已有的主要计算方法。在提出组合柱轴压承载力极限状态及组合柱轴压峰值应变的基础上,建立了组合柱轴压承载力计算公式。采用该文公式计算了34个组合柱试件的轴压承载力,计算值与试验值符合良好。为使轴心受压组合柱的峰值应变大于管外箍筋约束混凝土的轴压峰值应变、小于钢管混凝土的轴压峰值应变,提出了钢管混凝土截面面积在组合柱总面积中所占比例的上限值建议。 相似文献
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SMA混杂复合材料单层的被动阻尼 总被引:1,自引:0,他引:1
由形状记忆合金纤维、普通纤维、基体构成的混杂复合材料是一类用途广泛的智能材料结构系统。阻尼性能研究是结构被动振动控制的一项重要研究内容。本文采用混杂复合材料阻尼预测的细观力学理论计算SMA纤维混杂复合材料单层的阻尼特性。首先计算包含普通纤维和基体材料的复合材料介质的阻尼性能,其次计算由横观各向同性介质和SMA纤维构成的混杂材料的阻尼性能。通过计算实例分析SMA纤维混杂复合材料单层的正轴阻尼特性及其偏轴阻尼的特性随SMA纤维体积含量、纤维铺设角等参数改变的规律。 相似文献
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聚酰亚胺/无机粒子复合材料是一类具有优异综合性能的新型复合材料.综述了该类复合材料的制备方法,并概述了无机组分在聚酰亚胺中的微观形态结构控制方法,展望了聚酰亚胺/无机粒子复合材料的发展方向. 相似文献
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The in-plane compressive behaviors of 3-D textile composites, which including 3-D woven composite, multi-axial multi-layer
warp knitted (MMWK) composite and 3-D braided composite, were studied at quasi-static and high strain rate compression loading.
The compression behaviors at high strain rates (600∼2,500/s) were tested with split Hopkinson pressure bar (SHPB). The quasi-static
compressive tests were conducted on a MTS 810.23 tester and compared with the results at high strain rates. The comparisons
indicate that the compression stiffness, failure stress and failure strain for the three kinds of 3-D textile composites are
sensitive to strain rate. The MMWK composite has higher failure stress than the 3-D woven composite and 3-D braided composite
at the same strain rate; however, the failure strain of the 3-D braided composites is higher than that of the 3-D woven composite
and 3-D knitted composite at quasi-static compression because of the quasi-isotropic structure feature in the 3-D braided
composite. The compressive failure modes of the 3-D woven composite, MMWK composite and 3-D braided composite are totally
different because of the different preform structure. 相似文献
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玻璃纤维增强树脂(GFRP)-混凝土组合梁由上部混凝土板和下部GFRP型材以及连接二者的抗剪连接件组成。开展了2根GFRP-混凝土组合梁(非预应力及施加体外预应力组合梁各1根)在1年持续载荷下行为的试验研究。考虑混凝土收缩徐变及GFRP型材蠕变耦合的影响,开展了50年的24根GFRP-混凝土组合梁时随有限元参数分析。结果表明:在1年持续载荷下,非预应力与施加体外预应力组合梁长期挠度分别为其初始挠度的1.42倍及2.91倍;非预应力与预应力组合梁中连接件的长期滑移分别为0.230 mm及0.164 mm,相比初始滑移2种组合梁的最终滑移分别增加了53.3%和58.2%;50年后,非预应力组合梁长期挠度与初始挠度的比值在1.50~1.56之间;而施加体外预应力组合梁长期挠度与初始挠度的比值在3.03~6.08之间。基于以上研究提出了GFRP-混凝土组合梁长期挠度的计算建议。 相似文献
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In this paper the damage behaviour of natural stitched composite single lap-joints are investigated under low velocity impact loading conditions. For this study, the laminated hybrid composite beams were pinned using Flax yarns before curing process. The Charpy impact test was chosen to study the energy absorbing capability of single lap composite joints. Composite beams were fabricated from combination of glass/epoxy and carbon/epoxy composites. It was shown that composite beams which are stitched through the thickness are able to absorb more energy in comparison with adhesive bonded composite joints in the hybrid composite beams. The Charpy impact test of stitched composite single lap joint was also simulated by finite element analysis using software LS-DYNA and the results verified with relevant experimental data. 相似文献
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Composite lead-free electronic solders 总被引:1,自引:0,他引:1
Fu Guo 《Journal of Materials Science: Materials in Electronics》2007,18(1-3):129-145
Composite approaches have been developed in lead-free solder research in an effort to improve the service temperature capabilities
and thermal stability of the solder joints. This article overviews the background for composite lead-free solder development,
the roles of reinforcements and their requirements, composite solder processing techniques, as well as current status of composite
solder research. Examples of several representative lead-free composite solders produced with various methods and reinforcement
types are presented. The effects of reinforcement addition on processing and mechanical properties are analyzed. Difficulties
and problems that exist in composite solder research are proposed and tentative solutions are attempted with examples of newly
emerging novel lead-free composite solders. 相似文献