Sushant K Rawal
材料科学技术（英文）
The objective of the present work is to investigate the effect of various sputtering parameters such as nitrogen flow rate, deposition time and sputtering pressure on structural, wettability and optical properties of titanium oxynitride films deposited on glass substrate by reactive magnetron sputtering. The X-ray diffraction graphs of titanium oxynitride films show evolution of various textures of TiOxNy and TiN phases with increasing nitrogen flow rate and deposition time, but an increase in sputtering pressure from 4.0 to 8.0 Pa results in decline of various textures observed for TiOxNy and TiN phases. The stress and strain calculated by sin2Ψmethod are compressive, which decrease with increasing nitrogen flow rate from 55 to 100 sccm (standard cubic centimeter per minute) and increase with increasing deposition time from 80 to 140 min due to atomic penning effect and increasing thickness of the deposited films. The titanium oxynitride films have contact angle values above 90 deg., indicating that films are hydrophobic. The maximum contact angle of 109.1 deg. is observed at deposition time of 140 min. This water repellent property can add value to potential protective, wear and corrosion resistant application of titanium oxynitride films. The band gap decreases from 1.98 to 1.83 eV as nitrogen flow rate is increased from 55 to 100 sccm; it decreases from 1.93 to 1.79 eV as deposition time is increased from 80 to 140 min as more nitrogen incorporation results in higher negative potential of valence band N2p orbital. But it increases from 2.26 to 2.34 eV for titanium oxynitride films as sputtering pressure increases from 4.0 to 8.0 Pa.
关键词:
Titanium oxynitride
段沐枫
,
李宁
,
郑莹莹
,
肖军
,
李勇
宇航材料工艺
K-cor是应用Z-pin增强技术的一种新型高性能结构.本文以NHZP-1树脂为基体研究适合K-cor结构的半固化Z-pin拉挤工艺,得到固化度为51.25％的Z-pin为满足制备要求的最佳参数,并制作悬空装置采用两步法进行半固化Z-pin的植入和压弯,探索出压弯和后固化工艺.在此基础上,对试制的K-cor夹层结构进行平拉和剪切试验研究.结果发现,折弯长度是K-cor夹层结构的另一重要参数,较长的折弯长度会增加Z-pin与蒙皮的结合面积从而提高结构的拉伸性能.
关键词:
复合材料
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半固化Z-pin
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K-cor夹层结构
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制备工艺
,
力学性能
陈篪
金属学报
本文证明我们所建议的关系: (da/dN)-C[(△K)~2-K_2~2/K_1~2-(△K)~2]~p能够很好地表达R=(K_(min)/K_(max))=常数时(da/dN)随△K的全部变化,其中P值在1左右,C约在3×10~(-3)—10~(-2)毫米/周之间。
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Materials Letters
Single crystals of K-doped blue bronze Rb0.15K0.15MoO3 and Rb0.3MoO3 have been investigated by measurements of the X-ray photoemission spectrum (XPS), electrical resistivity and thermoelectric power, respectively. Analysis of the XPS data reveals that two final states representing alternate screening channels coexist in Rb0.15K0.15MoO3. Compared with the pure bronze, the Mo sites of the doped sample contain less 4d electrons which reflected in the movement of Mo3d spectrum. Due to the discrepancy of electronic structure, the K ion doping results in the notable increase of the single particle activation energy and decrease of the thermoelectric power in the charge density wave state. (C) 2007 Elsevier B.V. All rights reserved.
关键词:
blue bronze;charge-density-wave;electronic structure;nonlinear transport;k0.30moo3;tl0.3moo3;k0.3moo3;moo3
稀土学报(英文版)
Cyclic oxidation test is a fundamental method to assess lifetime of materials in high temperature environment. Cycle length or cyclic frequency is one important variable in cyclic oxidation testing. In present work, cyclic oxidation tests were performed on cast K38 alloys with 0 wt.%, 0.1 wt.%, and 0.5 wt.% yttrium additions at 1 273 K respectively. Two cyclic frequencies were used to investigate the influence of cycle length (1 h vs. 20 h) on the high temperature oxidation behavior of superalloy. The results showed that the degradation of cast K38 alloy critically was dependent on the cyclic frequency. The yttrium addition was beneficial to reducing scale-growth rate, improving the scale adhesion and stress releasing, thereby increased the spallation resistance. It could be drawn that the effect of cyclic frequency was highly dependent on the scale adherence to the substrate.
关键词:
K38 superalloy;yttrium;cyclic oxidation;cyclic frequency;rare earths;high-temperature oxidation;adhesion;segregation;scales;spallation;chromia;alloys;growth;oxides
Physics Letters A
Except for a Peierls transition at T(p) = 180 K, a new transition around T = 270 K in K0.3MoO3 single crystals has been found as evidenced by the anomalies in electrical, magnetic and thermodynamic properties. This transition may be caused by the variation of carrier characteristics or of the charge transfer between cations and anions.
关键词:
高桦
,
王自强
,
杨成寿
,
周爱华
金属学报
本文用三点弯曲和四点弯曲试样,在K_Ⅱ/K_Ⅰ=0—14的范围内,对GC-4超高强度钢、30Cr2MoV中强度转子钢和稀土球墨铸铁进行了线弹性平面应变复合型脆断试验。结果表明:复合型裂纹的脆断开裂方向与现有的三种复合型理论符合较好;但是,复合型裂纹扩展阻力随K_Ⅱ/K_Ⅰ比值增加而增大,与现有复合型理论差别较大。 本文从塑性区的形状、大小和裂纹顶端在开裂方向的应力状态等方面对此问题进行了分析并指出,现有理论关于复合型裂纹扩展阻力与变形特征无关的假设,对于具有一定塑性变形能力的金属材料,是不合适的。文章还对简单且偏于安全的处理复合型问题的工程分析方法作了讨论。
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