LIU Chunpeng XU Yousheng HUA Yixin Kunming Institute of Technology
,
Kunming
,
650093
,
China.
材料科学技术（英文）
In applying the microwave radiation to extractive me- tallurgy,it is essential first of all to find the extent of microwave energy absorbed by various minerals experi- mentally.In this paper,more than 25 kinds of common useful minerals have been individually irradiated by a 500 W,2450 MHz microwave source in an enclosed quartz crucible to ascertain their heating temperature in a definite time.In addition,the reduction and cbloridization tests were also carried out on the titanomagnetite concentrate and pentlandite with microwave heating,respectively. These experiments indicate potential applications of util- izing microwave energy in extractive metallurgy.
关键词:
microwave radiation
,
null
,
null
,
null
Z. T. Ma and D. Janke(Institute of Iron and Steel Technology
,
Freiberg University of Mining and Technology
,
Germany)
金属学报(英文版)
Useder certain conditions, nonmctallic inclusions such as oxides, sulfides, nitrides and carbides are no longer harmful to sted service properties. With the new concept of oxide metallurgy, these properties can be improved by generating fine oxide inclusions which serve as heterogeneous nuclei for sulfide and fine ferrite[1-4]. A novel continuous casting (CC) process is expected to be created with the utilization of oxide metallurgy. This is also useful for the forthcoming technologies of direct rolling and near-net-shape casting. The main idea of oxide metallurgy consists of an alternative oxidation technology. It is based on steels treated by complex metals such as Ti, Zr, Ti-Zr alloys and rare earth metals. The selected deoxidants should follow the required conditions which are concluded in this paper.
关键词:
oxide
,
null
,
null
,
null
Yong LIU
,
Lifang CHEN
,
Weifeng WEI
,
Huiping TANG
,
Bin LIU
材料科学技术（英文）
Ti-4.5Al-6.0Mo-1.5Fe, Ti-6Al-1Mo-1Fe and Ti-6Al-4V alloys were prepared by blended elemental powder metallurgy (PM) process, and the effects of Nd on the microstructures and mechanical properties were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). It was found out that the addition of Nd increased the density of sintered titanium alloys slightly by a maximum increment of 1% because small amount of liquid phase occurred during sintering. The addition of Nd shows little effect on the improvement of tensile strength, while the elongation is significantly improved. For example, the elongation of Ti-4.5Al-6.0Mo-1.5Fe can be increased from 1% without addition of Nd to 13% at a Nd content of 1.2 wt pct.
关键词:
Powder metallurgy titanium alloy
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null
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null
,
null
夏春霞
,
闫亚明
,
邓蜀平
,
白光君
,
蒋云峰
,
宋惠森
,
王钰
新型炭材料
doi:10.3969/j.issn.1007-8827.2001.04.013
聚丙烯腈(Polyacrylonitrile缩写为PAN)基炭纤维市场需求旺盛,但由于我国PAN基炭纤维生产企业规模小、产品性能低,产品占领不了市场,企业效益欠佳.通过经济规模方法的分析,就国内现有技术状况和两个样本生产线,用工程技术法对PAN基炭纤维的经济规模进行分析,为我国炭纤维产业化发展提供参考.分析表明,国内PAN基炭纤维经济规模的起点为200t/a～275t/a.
关键词:
PAN基炭纤维
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经济规模
,
工程技术法
李常清
,
袁姗
,
罗荣
,
郭雅明
,
徐樑华
高分子材料科学与工程
将聚酰亚胺(PI)加入丙烯腈-衣康酸-二甲基亚砜体系进行聚丙烯腈(PAN)溶液聚合,湿法纺丝制备了PAN/PI复合纤维.利用流变仪、红外光谱、X射线衍射仪、扫描电镜、差示扫描量热仪等研究了PAN/PI溶液的性质和复合纤维的结构特点.研究发现,加入PI后,聚合物溶液的稳态黏度降低,弹性和粘性模量在低剪切速率区降低;PI作为成核剂,引起初生纤维结晶度增大、晶粒尺寸减小;PI与PAN的溶解性差异导致凝固加快,初生纤维形成皮芯结构;引起原丝体密度减小.PAN/PI纤维在N2下放热量较少,在空气中由于结构疏松放热量较大.
关键词:
聚丙烯腈纤维
,
聚酰亚胺
,
原液改性
,
晶态结构
A.A.A. Saleh
,
Y. Fu
,
X.J. Zhai
金属学报(英文版)
Nano-ZnO particle was produced by evaporating zinc powders in air at air °ow-rate
from 0.2 to 0.6m3/h. Nano-ZnO particles was formed by the oxidation of the evapo-
rated zinc vapor. X-ray di®raction shows the powders to be ZnO with lattice parame-
ters of a=0.3249nm and c=0.5205nm. The particle size is dependent upon the transit
time from the source to the collection area. The size of particles was ranged between
81 to 103nm. The average density resulted was 4.865g/cm3.
Normal ZnO and nano-ZnO were investigated to use them in aluminum metallurgy as
an inert anode material. A certain amount of both oxides were molded subsequently
inserted to the molten cryolite-aluminum oxide to investigate the corrosive behavior
of both oxides. When the sintering temperature increased up to 1300±C, the weight
loss ratio rose to 5.01%{7.33% and up to 7.67%{10.18% for nano-ZnO and normal
ZnO, respectively. However, when the samples in the molten cryolite aluminum oxide
were put for long time, the corrosive rate was found to be higher. It was found that
the corrosive loss weight ratio of nano-ZnO anode was much lower than the normal
one made from ordinary-ZnO providing that the nano-ZnO is more possible to be use
inert anode material.
关键词:
reactive evaporation method
,
null
,
null
谢奔
,
朱波
,
王政
,
井敏
,
王进军
,
张春雷
,
吴益民
功能材料
为了提高聚丙烯腈（PAN）初生纤维的可拉伸性能,将溶液纺丝得到的初生纤维进行不同时间的恒温干燥处理,研究其拉伸性能随干燥时间的变化规律。结果表明,干燥处理可以大幅度提升PAN初生纤维的力学性能,其拉伸强力可达10.3cN,断裂伸长可达263.5%;随着干燥时间的延长,纤维的可拉伸性能增强,经过10h干燥后的初生纤维具有最佳可牵伸性能;而拉伸速率的提高可以有效促进未干燥初生纤维的拉伸变形,而对干燥处理后纤维的拉伸性能的影响不大。用SEM观察纤维断裂形貌发现,PAN纤维的致密性随牵伸比的增加而提高。
关键词:
聚丙烯腈
,
初生纤维
,
干燥
,
拉伸性能
,
断裂形貌
