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排序方式: 共有427条查询结果,搜索用时 15 毫秒
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高速短程纺技术能生产三维卷曲短纤维,该技术的关键之一是热流体喷射装置。本文介绍了热流体喷射装置的演变与特点及它的加工机理和某些已应用的实际装置。 相似文献
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指出生物非光滑耐磨表面现象的普遍性,对贝壳、牙齿等几种天然生物耐磨表面几何形态特征进行了分析,并介绍了加工耐磨表面的几种技术方法及非光滑耐磨技术在工程中的应用。同时,对非光滑耐磨理论与技术方法中存在的问题及发展趋势进行了分析与展望。 相似文献
4.
Jagtar Singh Mohammad Farooq Wani 《International Journal of Applied Ceramic Technology》2021,18(5):1853-1862
Tribological properties of Ti3SiC2 ceramic and Ti3SiC2/GNP composite were investigated using fretting sliding against Si3N4 ball counter body at a load of 50 N for a sliding distance of 900 m, under non-textured lubricated (NTL), textured lubricated (TL) condition, and textured lubricated high temperature (TLHT). This paper presents the influence of laser surface texturing (LST) on Ti3SiC2 and its graphene nanoplatelets (GNP) reinforced composite established through spark plasma sintering (SPS), tested under fretting wear conditions. The coefficient of friction and wear rate of Ti3SiC2 and its graphene nanoplatelets reinforced composites were incontrovertibly enhanced with laser surface texturing as compared to non-textured Ti3SiC2 and its GNP composite. The TL surface of Ti3SiC2 composite reinforced with 15% GNP showed the lowest COF and wear rate. Almost negligible changes were observed for TLHT tests. The LST proved to an efficient technique for enhancing the friction and wear properties of Ti3SiC2 and Ti3SiC2/GNP composite. 相似文献
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Raymond Brennan Carli Moorehead Victoria Blair Krista Limmer 《Materials and Manufacturing Processes》2018,33(1):93-98
Energy coupled to matter (ECM) concepts such as magnetic field–assisted processing were used to align rare earth–doped alumina ceramics in the presence of applied fields. The addition of gadolinium and ytterbium dopants to alumina increased the magnetic susceptibility anisotropies, and induced magnetic torques that led to significant alignment of ceramic particles under the application of magnetic fields as low as 1.8?T. In comparison, undoped alumina materials showed minimal alignment under applied field strengths as high as 9?T. Density function theory modeling indicated that the specific dopant type dictated changes in the magnetic properties of different rare earth–doped alumina systems by directly affecting the magnetic moment localization and magnetocrystalline anisotropy. 相似文献
7.
利用Na2CO3/NaHCO3的混合溶液,以Na2SiO3作为添加剂,对单晶硅表面进行了各向异性腐蚀,研究了溶液中NaHCO3的含量、腐蚀时间和温度以及加入Na2SiO3量对绒面的影响.结果表明,硅片在含有10%Na2CO3/5%NaHCO3/5%Na2SiO3的腐蚀液中于90℃恒温腐蚀25min可制备出均匀的具有金字塔结构的减反射绒面;通过将织构液置于密封的环境下,可以增强小尺寸金字塔的均匀分布;腐蚀液中加入硅酸钠可以减小金字塔尺寸,降低表面反射率. 相似文献
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The aim of this work was to show that with the use of the surface roughness parameters Ssk and Sku we can predict tribological behavior of contact surfaces and use these parameters to plan surface texturing. This article presents a continuation of our research on virtual texturing and experimental work on surface textures in the form of channels. For this investigation, steel samples were laser surface textured in the shape of dimples with different spacings between the dimples and different dimple depths. The experimental results confirmed that the parameters Ssk and Sku can be used to design the surface texturing, where a higher value of Sku and more negative Ssk lead to lower friction. 相似文献
9.
《中国工程学刊》2012,35(1):69-77
This study investigates the effects of different recipes and concentrations of surfactant on the texture and reflectance of a multi-crystalline silicon wafer surface. The morphology of the surface was examined and photographed using a field emission scanning electronic microscope. The reflectance of the surface was measured and analyzed using a self-designed optical system. The results of this study show that a higher hydrocarbon-surfactant (CH-surfactant) concentration in the etchant resulted in a slower reaction time. The optimum concentration of CH-surfactant was 1%. However, there were many white bubbles in the etching process. The optimum recipe for surfactant included fluoride 2% to diminish these bubbles. The reflectance was less than 22% in visible light. This cost effective acid chemical etching method is suitable for texturing silicon surfaces on 50?nm nanostructures. This is a critical criterion for determining the optimum recipe for surface texturing of acidic etching in solar cells. 相似文献
10.
In efforts to investigate the influence of the surface texturing on the Si3N4/TiC ceramic, laser surface texturing (LST) was performed on the Si3N4/TiC ceramic by an Nd:YAG laser and different geometrical characteristics of regular-arranged micro-grooved textures were fabricated on the surfaces. The tribological properties of the textured and smooth samples were investigated by carrying out sliding wear tests against steel balls under dry condition using a ball-on-disk tribometer. Effect of surface texturing on the stress distribution was studied by finite element method (FEM). Results show that the textured surfaces exhibited lower friction coefficient and excellent anti-wear properties compared with smooth surfaces. The tribological characteristics depended greatly on the size and density of the micro-grooves, and the geometrical characteristics of the surface textures have a significant effect on the tribological behavior. Among the patterns investigated, the wavy-grooved samples exhibit the lowest friction coefficient and wear rate; and a large texture density may be the best for reduction of friction and wear of textured samples. While, the wear rate of balls sliding against textured surfaces is larger than that of balls sliding against smooth surfaces. FEM results show that surface texturing can improve the stress distribution of contact interfaces and reduce stress concentration. 相似文献