MJ.Kim
,
Y.B.Kim
,
C.B.Song
,
Y.Li
,
D.S.Suhr
,
C.O.Kim
,
T.K.Kim
材料科学技术（英文）
The magnetic properties and microstructure of diffusion annealed [Ta/Nd/NdFeB/Nd/Ta] thin films have been investigated. The films were deposited on Si substrate with various thickness ratio of Nd/NdFeB layer (R=0 similar to 3.3), then diffused and crystallized by annealing at 650 degrees C for 10 min. The film without Nd layer showed soft magnetic behavior and high content of alpha-Fe phase. The films with R greater than or equal to 1 showed good hard magnetic properties with the high coercivity of about 20 kOe.
关键词:
T.S.Yoont
,
W.S.Cio
,
C.O.Kim
,
H.W.Kang
,
Y.H.Kim
材料科学技术（英文）
To obtain microstructure of magnetic devices, the thin film inductors were fabricated by the process such as thin film manufacturing, photolithography and wet etching. The frequency characteristics of these devices are measured at high frequency range. When the inductor sizes of the spiral and the meander type are same, the inductance and the quality factor of the spiral type inductor are larger than those of the meander type inductor, but the driving frequency of the spiral type inductor is fewer than that of the meander type inductor.
关键词:
W.S.Cho
,
T.S.Yoon
,
C.O.Kim
,
H.B.Lee
材料科学技术（英文）
The transverse permeability ratio (TPR) and longitudinal permeability ratio (LPR) as a function of an external field of mumetal films have been investigated in conjunction with the magnetic properties. The mumetal films were prepared by the R.F.magnetron sputtering method in Ar atmosphere. The LPR curve shows the single peak pattern, and the TPR curve shows the double peak pattern indicating the existence of the magnetic anisotropy effect. The magnitude of the incremental permeability are strongly depended on the magnetic softness. The large changes of LPR and TPR in low external fields can be useful for the evaluation of the magnetic softness.
关键词:
刘军
,
宋永才
,
冯春祥
宇航材料工艺
doi:10.3969/j.issn.1007-2330.2001.02.008
采用将聚二甲基硅烷与聚氯乙烯共裂解合成制备了si-C-O纤维先驱体聚合物，并对其进行了表征。表明反应体系中聚氯乙烯含量较高时，生成的先驱体聚合物既有聚碳硅烷的结构特征，又具有—CH＝CH—共轭结构特征的一(SiCH3H-CH2)n—(CH＝CH)m—共聚物。先驱体聚合物经熔融纺丝及NO2不熔化处理，高温烧成制得低电阻率Si—C—O纤维(电阻率小于100Ω.cm)，而通过聚碳硅烷制得的SiC纤维电阻率为106Ω.cm。结果表明能够从聚二甲基硅烷与聚氯乙烯共裂解出发制备低电阻率Si—C—O纤维。
关键词:
碳化硅纤维
,
电阻率
,
制备
乔瑜
,
姚洪
,
王臣
,
徐明厚
工程热物理学报
计算包含详细反应机理的复杂反应流问题仍然是十分费时的,已有的反应流计算方法通常采用简化的化学反应机理.传统的机理简化方法大多基于反应条件的稳态假设,如主量组分分析法等.近年来,一种基于自适应化学理论的机理简化的新方法被提出.该方法根据设定的化学精度要求,可实现详细反应机理的最优简化.对Sn/O/H/N/C/Cl详细反应机理的简化结果表明Sn+CO2=SnO+CO和Sn+O2=SnO+O为机理中影响Sn氧化最重要的两个基元反应.
关键词:
反应流
,
反应机理
,
机理简化
,
Sn
孙德明
,
刘立红
,
许崇海
,
刘玉婷
,
鹿晓阳
,
赵国群
机械工程材料
doi:10.3969/j.issn.1000-3738.2005.08.015
热压烧结制备了Al2O3/Cr3C2/(W,Ti)C复合陶瓷材料,对其抗弯强度及组织形貌进行了研究,分析了Cr3C2与(W,Ti)C对抗弯强度的影响.结果表明:添加(W,Ti)C与Cr3C2有利于阻止晶界迁移,延缓晶粒长大,提高材料强度,但每一相的添加量以10%内为宜,两者添加总量在20%左右时Al2O3/Cr3C2/(W,Ti)C复合材料抗弯强度较佳.铬、钨、钛离子在Al2O3基体晶粒中的固溶起强化作用,网状结构是降低材料抗弯强度的重要原因.
关键词:
Cr3C2
,
(W,Ti)C
,
Al2O3陶瓷
,
抗弯强度
Journal of Materials Science
Creep behaviour of 10 vol % SiC particulate-reinforced Al-C-O composite has been investigated at the temperatures of 623 and 723 K. The addition of SiC particulates in Al-C-O alloy decreases creep rates by two to four orders of magnitude, compared with Al-C-O matrix alloy. The stress and temperature dependences of creep rates of the composite are similar to those of the Al-C-O matrix alloy. The threshold stress for creep was used to analyse the experimental data of the composite. The creep rates of the composite are concluded to be controlled by lattice diffusion of aluminium. (C) 1998 Kluwer Academic Publishers.
关键词:
high-temperature creep;matrix composites;aluminum composite;alloys
姚栋嘉
,
李贺军
,
付前刚
,
陶珺
,
王永杰
中国材料进展
采用包埋法和低压化学气相沉积（CVD）法在碳／碳（C／C）复合材料表面依次制备了Ta2O5-TaC内涂层和SiC外涂层，用X射线衍射分析（XRD）、扫描电镜（SEM）及电子能谱（EDS）对涂层的相组成、微观形貌和元素组成进行了分析，研究了涂覆涂层后C／C复合材料在1500℃静态空气中的防氧化性能及在氧-乙炔烧蚀中的抗烧蚀性能。结果表明：采用两步法制得的Ta2O5-TaC／SiC复合涂层结构致密，该复合涂层有效提高了C／C复合材料的抗氧化和抗烧蚀性能；Ta2O5-TaC／SiC复合涂层在1500℃静态空气环境下可对C／C复合材料有效保护100h以上；涂层试样在氧乙炔烧蚀环境中烧蚀60S表明涂层可将C／C复合材料的线烧蚀率降低47．07％。质量烧蚀率降低29．20％。
关键词:
C/C复合材料
,
CVD-SiC涂层
,
Ta2O5-TaC涂层
,
抗氧化
,
抗烧蚀
