共查询到20条相似文献,搜索用时 109 毫秒
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电沉积法制备磷酸钙生物活性陶瓷涂层 总被引:2,自引:1,他引:1
综述了用电沉积法在金属生物材料表面涂敷磷酸钙生物活性陶瓷的工艺,分析了电沉积工艺的特点,并介绍了制备金属-羟基磷灰石复合涂层的复合电沉积工艺。 相似文献
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对铝基材实施阳极氧化处理,可在其表面形成氧化铝多孔膜。当氧化铝多孔膜的纳米孔排列成规则的阵列结构时,氧化铝多孔膜将具有许多其它纳米材料无法比拟的优势。综述了以具有规则纳米孔阵列结构的阳极氧化铝薄膜作为模板,通过复制、沉积、吸附等技术,制备具有各种特殊用途纳米材料的制备工艺,使用这些方法制备的纳米材料已经广泛地应用于催化、气体吸收、分离膜、微电子器件等。 相似文献
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水泥中掺入大量矿物掺合料易造成其早期强度低、施工周期长等问题。本文研究了C-S-H晶核对含矿物掺合料的复合胶凝材料体系水化性能的影响规律;通过热力学计算阐述了C-S-H晶核降低水化产物成核势垒的机理,并通过离子溶出与沉积探讨大掺量矿物掺合料胶凝体系水化机理。结果表明:矿物掺合料复合胶凝材料体系水化能力较弱,这是由于Ca2+溶出受到制约,C3S的水化反应缓慢;当加入晶核后,水泥中硅酸盐相溶解-结晶能力得到大幅提升,使得矿物掺合料水泥体系的水化反应活性接近纯水泥体系。研究表明,C-S-H晶核可解决大掺量矿物掺合料胶凝体系所带来的水化能力严重不足问题。 相似文献
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纳米晶体材料具有优异的力学性能,近年来,不少国内外研究者对纳米晶体材料的力学行为和本构模型进行了深入的研究。有针对性地回顾了国内外纳米晶体材料本构模型的研究工作,对国际上最新成果进行了评述,指出了尚未解决的一些关键技术问题。结合相关领域的最新研究成果,提出了今后应着重研究的4个关键点分别为:纳米晶体相与应变速率和晶粒尺寸相关的变形机理和本构方程、晶界相与应变速率和晶粒尺寸相关的变形机理和本构方程、含孔隙多相复合夹杂体的协调变形力学理论研究、实验制备和表征,并就这4个关键点提出了一些思路与建议。 相似文献
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An additive free synthesis of nanocrystalline zinc oxide using microwave technique is reported. The current methodology is faster, cleaner and cost effective compared with conventional method for the synthesis of zinc oxide nanocrystalline materials. The structure and morphology of nanocrystalline zinc oxide was investigated by TEM, XRD, EDAX and UV-vis spectroscopy. The results demonstrate that microwave heating can produce polygonal zinc oxide within a short span of time. 相似文献
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Igor Petrusha Chawon Hwang Tatiana Prikhna Metin Örnek Dexin Zhao Kelvin Y. Xie Richard A. Haber Myroslav Karpets Semyon Ponomaryov Sergey Dub Viktoer Moshchil 《Journal of the European Ceramic Society》2021,41(11):5505-5511
Synthesizing bulk nanocrystalline materials is challenging since grain growth should be suppressed whereas densification promoted. Here, we demonstrate a novel route to synthesize superhard bulk nanocrystalline cubic boron nitride (cBN), which combines the use of emulsion detonation and high-pressure high-temperature transformation-assisted consolidation. The emulsion detonation process activates BN to possess unique structure and chemistry, i.e. wurtzitic BN nanograins in hexagonal BN matrix with enhanced structural disordering and oxygen impurity, a combination that enhances the nucleation rate of cBN and its densification leading to the formation of bulk nanocrystalline cBN at reduced conditions. The cBN, synthesized at 7.5 GPa and 1800 °C, displayed Vickers hardness values of 50?62 GPa for 5?20 N loads. The findings in the study suggest a feasible solution to synthesize bulk nanocrystalline cBN in a more scalable way, while also providing design insights on how to refine grain growth while enhancing densification to synthesize bulk nanocrystalline materials. 相似文献
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ABSTRACT: The emergence of third-generation photovoltaics based on Si relies on tunable bandgap materials with embedded nanocrystalline Si. One of the most promising approaches is based on the mixed-phase Si1 - xCx. We have investigated the light absorption controllability of nanocrystalline Si-embedded Si1 - xCx produced by thermal annealing of the Si-rich Si1 - xCx and composition-modulated superlattice structure. In addition, stoichiometric SiC was also investigated to comparatively analyze the characteristic differences. As a result, it was found that stoichiometric changes of the matrix material and incorporation of oxygen play key roles in light absorption controllability. Based on the results of this work and literature, a design strategy of nanocrystalline Si-embedded absorber materials for third-generation photovoltaics is discussed. 相似文献
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《Journal of the European Ceramic Society》2023,43(4):1746-1750
Short-range order is a new strengthening effect that can significantly affect the mechanical properties of high-entropy materials. Furthermore, simulation results show that this strengthening effect at a quasi-atomic scale can suppress the grain size softening, leading to the disappearance of inverse Hall-Petch behavior in nanocrystalline high-entropy materials. In this work, the evident inverse Hall-Petch behavior is confirmed in the translucent nanocrystalline high-entropy ceramic (HEC) with an average grain size below 10 nm, fabricated by a high-pressure low-temperature sintering technique. Besides, the as-obtained nanocrystalline HEC also shows an improving fracture toughness compared with the corresponding coarse-crystalline HEC. 相似文献