Q.L.Deng1)
,
W.D.Huang1)
,
Y.H.Zhou1)
,
C.Y.Yu2)
,
Y.K.Zhang2)
,
Y.X.Tang2) and H.Zhang2) 1) State Key Lab .of Solidification Processing
,
Northwestern Polytechnical University
,
Xi’an 710072
,
China 2) Mechanical Department
,
Nanjing University of Aeronautics & Astronautics
,
Nanjing 210016
,
China
金属学报(英文版)
The mechanism oflasershock processing wasanalyzedinthispaper. Westudyexperimentallythelasershock processingon 2024 T62 aviation aluminium alloys. Theexperimental results show thefatiguelife of 2024 T62 aviation aluminium alloysshocked by a laserisimprovedgreatly.
关键词:
lasershock processing
,
null
,
null
Oxidation of Metals
The oxidation of Fe- Y alloys containing 2 and 5 at.% Y and pure iron has been studied at 600-800 degrees C in air. The oxidation of pure iron follows the parabolic rate law at all temperatures. The oxidation of Fe-Y alloys at 600 degrees C approximately follows the parabolic rate law, but not at 700 and 800 degrees C, where the oxidation goes through several stages with quite different rates. The oxide scales on Fe-2Y and Fe-5 Y at 700 and 800 degrees C are composed of external pure Fe oxides containing Fe2O3, Fe3O4, and FeO, with FeO being the main oxide and an inner mixture of FeO and YFeO3. The scales on Fe-2Y and Fe-5Y at 600 degrees C consist of Fe2O3, Fe3O4, and Y2O3, with a minor amount of FeO. Significant internal oxidation in both Fe-Y alloys occurred at all temperatures. The Y-containing oxides follow the distribution of the original intermetallic compound phase in the alloys. The effects of Y on the oxidation of pure Fe are discussed.
关键词:
pure Fe;Fe-Y alloys;oxidation;high-temperature oxidation;possible scaling modes;2-phase;binary-alloys;low-oxygen pressures;oxidant pressures
Journal of Applied Physics
The magnetic properties of R2Co14B1-xCx (x=0, 0.5 and R=Y, Sm) compounds have been studied by measuring the temperature dependence of the easy- and hard-magnetization curves on magnetically aligned samples between 1.5 and 300 K for Y2Co14(B,C) and at 4.2 K for Sm2Co14(B,C). The magnetic anisotropy of Y2Co14B increases due to the substitution of C for B, whereas the saturation magnetization decreases. Between 1.5 and 300 K, the anisotropy field of Y2Co14B0.5C0.5 increases about 2 T and the Co moment decreases about 0.05mu(B). The anisotropy field Of Sm2Co14B also increases upon C substitution and the saturation magnetization decreases slightly. The ac susceptibilities of both SM2Co14B and Sm2Co14B0.5C0.5 exhibit anomalies that may arise from a spin reorientation within the basal plane.
关键词:
nd2fe14b;exchange;nd2co14b;r2fe14b;field
Journal of Applied Physics
Y2Fe14B0.5C0.5 has the same tetragonal structure as Y2Fe14B with space group P4(2)/mnm. Magnetic properties of the Y2Fe14B0.5C0.5 compound have been studied using an extraction magnetometer with a maximum field of 6 T, in the temperature range from 1.5 to 300 K. By means of fitting the hard magnetization curves, the magnetocrystalline anisotropy constants K1, K2, and K3 were determined. It was found that although the magnetocrystalline anisotropy field (mu-0H-a) increases abnormally with increasing temperature as in the case of Y2Fe14B, the dependence of anisotropy constants on temperature is quite different from that of Y2Fe14B. K1 and K3 decrease slightly with increasing temperature. K2 increases abnormally with increasing temperature, which contributes to the abnormal dependence of anisotropy field on temperature. In addition, the substitution of carbon for boron leads to a reduction of 3d-3d interaction and spontaneous magnetization. In contrast, uniaxial anisotropy is increased by the addition of carbon below room temperature.
关键词:
alloys
材料科学技术（英文）
The corrosion of an Fe-based alloy containing 15 wt pet Y in H-2-H2S mixtures under 10(-3) Pa S-2 was studied at 600 similar to 800 degrees C in an attempt to find materials with improved sulphidation resistance with respect to pure Fe. The presence of Y has been shown to be beneficial, but not sufficient to the level expected. In fact, the alloy is able to form at all tested temperatures an external FeS layer, beneath which a zone containing a mixture of the two sulphides is also present. Thus, Fe can still diffuse through this region to form the outer FeS layer with non-negligible rate. The corrosion rate of Fe is considerably reduced by the Y addition, but the alloy corrodes still much more rapidly than Y. The sulphidation kinetics is generally rather irregular for both the pure metals, while the corrosion rate of the alloy decreases with time and tends to become parabolic after an initial period of 12 similar to 17 h. The sulphidation behaviour of the alloys is discussed by taking into account the presence of an intermetallic compound Fe17Y2 and the limited solubility of Y in Fe.
关键词:
high-temperature sulfidation;most-reactive component;ni-nb alloys;h2-h2s mixtures;behavior;600-degrees-c-800-degrees-c;oxidation
GUO Jin-hua
,
GAO Zhen
,
NI Xiao-jun
,
et al
钢铁研究学报(英文版)
Fe55Ni2Cr12Mo10B6C13Y2，Fe55Cu2Cr12Mo10B6C13Y2 and Fe55Nb2Cr12Mo10B6C13Y2 alloys with diameter of 4mm were produced by copper mold casting. The role of alloying additions (Ni, Cu or Nb) on corrosion resistance of Fe55Nb2Cr12Mo10B6C13Y2, Fe55Ni2Cr12Mo10B6C13Y2 and Fe55Cu2Cr12Mo10B6C13Y2 alloys were studied by polarization curves and electrochemical impedance spectroscopy (EIS). The results show that Fe55Ni2Cr12Mo10B6C13Y2 and Fe55Cu2Cr12Mo10B6C13Y2 alloys can be cast into bulk metallic glasses. Fe55Ni2Cr12Mo10B6C13Y2 and Fe55Cu2Cr12Mo10B6C13Y2 amorphous alloys with passive potential about 1500 mV exhibit good corrosion resistance in 5 % NaCl solution and 1 mol/L HCl solution. The passive current density of the alloy with Ni addition is lower than other alloys. EIS results only show one impedance element. Amorphous alloy Fe55Ni2Cr12Mo10B6C13Y2 with larger charge transfer reaction resistance indicates good corrosion resistance.
关键词:
amorphous;polarization curve;electrochemical impedance spectroscopy
沈保根
,
孔麟书
,
曹蕾
,
王芳卫
,
詹文山
,
郭慧群
,
赵见高
金属学报
用快淬方法制备了单相(Er_(1-x)Sm_x)_2Fe_(17)C_y(x=0.2,<3.0;x=0.5,y<2.0)化合物,研究了它们的形成、结构、稳定性及内禀磁性结果表明,它们在高温是稳定的,随碳含量的增加,晶体结构由六角的Th_2Ni_(17)型向菱方的Th_2Zn_(17)型转变间隙碳原子的引入导致了单胞体积的膨胀、室温饱和磁化强度和Curie温度的增加当y>1.0时,(Er_(1-x)Sm_x)_2Fe_(17)C_y样品在室温均显示出单轴各向异性
关键词:
(Er(1-x)Sm_x)_2Fe_(17)C_y间隙碳化物
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interstitial carbides
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magnetic properties
马青松
,
蔡利辉
中国有色金属学报(英文版)
doi:10.1016/S1003-6326(17)60044-X
以Y2O3粉和硅树脂配制成的浆料为原料,通过浸涂提拉法在C/SiC复合材料表面制备Y2Si2O7涂层,研究Y 2 Si 2 O 7相的合成、涂层结构和氧化保护效果以及抗氧化机制.结果表明,质量比为54.2:45.8的Y 2 O 3粉/硅树脂混合物先在800℃空气中裂解再在1400℃ Ar惰性气氛下热处理,能够完全转化成Y2Si2O7.Y2Si2O7涂层致密度高且与基体结合紧密,在氧化过程中发生进一步致密化而呈现出优异的抗氧化性能,分别在1400、1500和1600℃氧化30 min后,复合材料的强度保留率达到130%~140%.此外,在1500℃下Y2Si2O7涂层会与氧化铝支撑体之间发生反应,生成具有低共熔点的Y?Si?Al?O玻璃相.
关键词:
C/SiC复合材料
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硅酸钇
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涂层
,
抗氧化性
黄新平
,
李漠
,
吕宝军
,
赵军
,
艾兴
,
高秀生
机械工程材料
doi:10.3969/j.issn.1000-3738.2004.08.006
Y2O3-Al2O3为复合烧结助剂,以(W,Ti)C为增韧补强材料,制备了Si3N4基复合陶瓷材料.研究了Y2O3和Al2O3的配比、体积分数对Si3N4/(W,Ti)C力学性能、致密化进程和烧结性能的影响.结果表明:两者配比为2:3、总体积分数为10%时,可以获得较高的致密度和较好的烧结性能,材料力学性能最好,抗弯强度845MPa,显微硬度16.45GPa,断裂韧度7.0MPa·m1/2.
关键词:
Si3N4
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复合陶瓷
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烧结助剂
,
致密化
