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71.
72.
TC11钛合金零件的激光熔化沉积修复研究 总被引:5,自引:1,他引:5
结合飞机起动机钛合金叶轮的修复需要,研究了Ti-6Al-3.5Mo-1.8Zr-0.23Si(TC11)钛合金激光熔化沉积修复工艺及界面的组织与力学性能。结果表明,激光熔化沉积TC11钛合金及界面重熔区具有典型的魏氏组织特征,基体热影响区组织逐渐由魏氏组织向双态组织过渡;激光熔化沉积TC11钛合金的抗拉强度高于界面过渡区及基体,而塑性稍低于基体。通过采用逐点熔化沉积的方法对叶轮受损叶片进行了修复,经加工检验后通过了超转试验考核,实现了装机应用。 相似文献
73.
Anodic titanium oxide TiO2 nanotube membranes with one, two and three layers have been prepared by the anodic oxidation method via adjusting applied bias during the oxidation process in glycol electrolytes containing 0.25 wt% or 0.50 wt% NH4F. The morphologies of the as-prepared samples were presented in detail using scanning and transmission electron microscopy. The results indicated that the glycol electrolyte containing 0.25 wt% NH4F yielded smooth double-walled nanotubes, and their tubes remained open in multilayers; while the glycol electrolyte containing 0.50 wt% NH4F yielded single-wall nanotubes with ripples, and most of the nanotubes have closed bottoms. In the case of nanotubes with closed bottoms, it was proposed that the newly grown nanotubes on the succeeding layer formed in the gap between the nanotubes of the previous layer. In order to keep track of the growth of the nanotubes, samples were anodized for different periods of time from 1 to 90 min to study their formation process. Growth mechanisms were proposed for different morphologies. 相似文献
74.
激光淬火对钛合金微动磨损性能影响的研究 总被引:2,自引:0,他引:2
研究了激光淬火对钛合金微动磨损性能的影响。结果表明:钛合金激光淬火后抗微动磨损能力有所提高,其提高幅度与微动幅度的大小和法向载荷的高低有关,在较大微动幅度或较高法向载荷的条件下,激光淬火可显著地提高钛合金抗微动磨损能力。 相似文献
75.
Large‐scale Synthesis of Urchin‐like Mesoporous TiO2 Hollow Spheres by Targeted Etching and Their Photoelectrochemical Properties 下载免费PDF全文
Jia Hong Pan Xing Zhu Wang Qizhao Huang Chao Shen Zhen Yu Koh Qing Wang Astrid Engel Detlef W. Bahnemann 《Advanced functional materials》2014,24(1):95-104
A versatile targeted etching strategy is developed for the large‐scale synthesis of urchin‐like mesoporous TiO2 hollow spheres (UMTHS) with tunable particle size. Its key feature is the use of a low‐temperature hydrothermal reaction of surface‐fluorinated, amorphous, hydrous TiO2 solid spheres (AHTSS) under the protection of a polyvinylpyrrolidone (PVP) coating. With the confinement of PVP and water penetration, the highly porous AHTSS are selectively etched and hollowed by fluoride without destroying their spherical morphology. Meanwhile TiO2 hydrates are gradually crystallized and their growth is preferentially along anatase (101) planes, reconstructing an urchin‐like shell consisting of numerous radially arranged single‐crystal anatase nanothorns. Complex hollow structures, such as core–shell and yolk–shell structures, can also be easily synthesized via additional protection of the interior by pre‐filling AHTSS with polyethylene glycol (PEG). The hollowing transformation is elucidated by the synergetic effect of etching, PVP coating, low hydrothermal reaction temperature, and the unique microstructure of AHTSS. The synthesized UMTHS with a large surface area of up to 128.6 m2 g‐1 show excellent light‐harvesting properties and present superior performances in photocatalytic removal of gaseous nitric oxide (NO) and photoelectrochemical solar energy conversion as photoanodes for dye‐sensitized mesoscopic solar cells. 相似文献
76.
Solution Processing Route to Multifunctional Titania Thin Films: Highly Conductive and Photcatalytically Active Nb:TiO2 下载免费PDF全文
Davinder S. Bhachu Sanjayan Sathasivam Gopinathan Sankar David O. Scanlon Giannantonio Cibin Claire J. Carmalt Ivan P. Parkin Graeme W. Watson Salem M. Bawaked Abdullah Y. Obaid Shaeel Al‐Thabaiti Sulaiman N. Basahel 《Advanced functional materials》2014,24(32):5075-5085
This paper reports the synthesis of highly conductive niobium doped titanium dioxide (Nb:TiO2) films from the decomposition of Ti(OEt)4 with dopant quantities of Nb(OEt)5 by aerosol‐assisted chemical vapor deposition (AACVD). Doping Nb into the Ti sites results in n‐type conductivity, as determined by Hall effect measurements. The doped films display significantly improved electrical properties compared to pristine TiO2 films. For 5 at.% Nb in the films, the charge carrier concentration was 2 × 1021 cm?3 with a mobility of 2 cm2 V–1 s–1 . The corresponding sheet resistance is as low as 6.5 Ω sq–1 making the films suitable candidates for transparent conducting oxide (TCO) materials. This is, to the best of our knowledge, the lowest reported sheet resistance for Nb:TiO2 films synthesized by vapour deposition. The doped films are also blue in colour, with the intensity dependent on the Nb concentration in the films. A combination of synchrotron, laboratory and theoretical techniques confirmed niobium doping into the anatase TiO2 lattice. Computational methods also confirmed experimental results of both delocalized (Ti4+) and localized polaronic states (Ti3+) states. Additionally, the doped films also functioned as photocatalysts. Thus, Nb:TiO2 combines four functional properties (photocatalysis, electrical conductivity, optical transparency and blue colouration) within the same layer, making it a promising alternative to conventional TCO materials. 相似文献
77.
Miao Song Dehong Chen Yafeng Yang Maoqiao Xiang Qingshan Zhu Hongdan Zhao Liam Ward Xiao-Bo Chen 《Advanced functional materials》2021,31(6):2008028
Single-crystalline {100} faceted TiC is of great significance in theory to a large number of engineering applications owing to its extraordinary catalytic properties. However, the {111} planes are prevalent in conventional TiC powders given their favorable thermodynamic stability during the initial low stoichiometric growth stage. Herein, a disproportionation–decomposition strategy is developed to directly produce Ti and C atoms to synthesize single-crystalline {100} faceted TiC powders. Outstanding electrochemical performance of TiC {100} crystal planes in terms of the hydrogen evolution reaction is evidenced by an overpotential of 392 mV at 10 mA cm−2, which is 52% lower than that of randomly faceted TiC counterparts (815 mV). 相似文献
78.
钒钛磁铁矿选矿及综合利用 总被引:9,自引:0,他引:9
钒钛磁铁矿资源的开发利用为相应产业提供了不可替代的物质基础。选矿及综合开发利用技术进步较快,为该资源开发利用提供了成熟的工艺和技术。进一步研究开发目标是实施节能新工艺和全面综合开发利用以及建立现代矿业生态工业园示范区。 相似文献
79.
介绍了铬钒钛材质锻造及轧制的钢球在调军台选矿厂5 .49m× 8.83m球磨机生产应用的情况 ,探讨了大型溢流型球磨机对磨矿介质机械性能和球径、配比等方面的技术要求 ,使新建选矿厂磨机生产能力尽快达到设计水平。 相似文献
80.
为进一步研究航空主承力疲劳结构件损伤容限型钛合金的疲劳裂纹扩展问题,基于新版标准疲劳裂纹扩展试验方法GB/T 6398—2017,对两类损伤容限型钛合金TC4-DT及TC21进行测试。结果表明,低速扩展阶段,TC4-DT较TC21的疲劳裂纹扩展速率更小,宏观断口形貌粗糙度较大。当裂纹尖端应力强度因子范围ΔK处于24~31 MPa·m1/2的初始稳态扩展阶段时,裂纹扩展速率曲线基本重合,TC4-DT较TC21具有更长的稳态扩展区,断口形貌较为平滑。随裂纹长度的增加,应力强度因子范围ΔK约为断裂韧度KIC的50%时,进入失稳扩展阶段,断裂面粗糙度增加。 相似文献