ZHAO Xu
,
QI Min
,
YANG Dazhi Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
110015
,
China.Department of Materials Engineering
,
Dalian University of Technology
,
Dalian
,
116012
,
China.
材料科学技术（英文）
The effect of α phase on CuZnAl shape memo- ry alloy(SMA)has been systematically studied by electrical resistance method,quantitative measure- ment of micrography and transmission electron microscopy(TEM).It is found that,by controlling the amount of α phase in(α+β)-CuZnAl alloy, phase transformation temperatures can be adjusted precisely in a wide range,while the good shape memory effect of CuZnAl is kept.In a word, quenching from(α+β)dual phase region is a rea- sonable method of adjusting phase transformation temperatures for CuZnAl alloy.
关键词:
(α+β)-CuZnAl alloy
,
null
,
null
YUAN Siyu
,
ZHANG Liwen
,
LIAO Shulun
,
QI Min
,
ZHEN Yu
,
GUO Shuqi
钢铁研究学报(英文版)
An FE model was developed to study thermal behavior during the rod and wire hot continuous rolling process. The FE code MSCMarc was used in the simulation using implicit static arithmetic. The whole rolling process of 30 passes was separated and simulated with several continuous 3D elasticplastic FE models. A rigid pushing body and a data transfer technique were introduced into this model. The online experiments were conducted on 304 stainless steel and GCr15 steel hot continuous rolling process to prove the results of simulation by implicit static FEM. The results show that the temperature results of finite element simulations are in good agreement with experiments, which indicate that the FE model developed in this study is effective and efficient.
关键词:
FE analysis;thermal behavior;hot continuous rolling;3D deformation
CHANG Ying
,
WANG Dapeng
,
LI Wei
,
PAN Wei
,
YU Xiaojun
,
QI Min
钢铁研究学报(英文版)
Rare earth permanent magnetic materials are typical electrical conductor, and their magnetic properties will decrease because of the eddy current effect, so it is difficult to keep them stable for a long enough time under a high frequency AC field. In the present study, as far as rare earth permanent magnets are concerned, for the first time, rare earth permanent magnets with strong electrical insulation and high magnetic performance have been obtained through experiments, and their properties are as follows: (1) Sm2TM17: Br=062 T, jHc=8037 kA/m, (BH)m=5897 kJ/m3, ρ=7 Ω·m; (2) NdFeB: Br=0485 T, jHc=76633 kA/m, (BH)m=3796 kJ/m3, ρ=9 Ω·m. The magnetic properties of Sm2TM17 and NdFeB are obviously higher than those of ferrite permanent magnet, and the electric insulating characteristics of Sm2TM17 and NdFeB applied have in fact been approximately the same as those of ferrite. Therefore, Sm2TM17 and NdFeB will possess the ability to take the place of ferrite under a certain high frequency AC electric field.
关键词:
Sm2TM17;NdFeB;electrical insulation;eddy current
黄爱华
,
金鸣林
,
李和兴
,
房永征
材料导报
试验是以2种含不同QI的煤沥青为原料,采用变径反应管进行热转化反应制备有序性中间相的研究.试验采用偏光显微镜和扫描电镜(SEM)观察了原料各反应阶段的微观结构,考察了QI对热转化过程中中间相有序生长的影响,分析了热转化过程中软化点及族组分的变化.结果表明:少量的喹啉不溶物含量不会阻碍中间相有序的发展.高QI(2.03%)原料易生成镶嵌结构的中间相体,高温处理后样品呈轴状、短纤维、层片松散的石墨化焦结构;含低QI(0.11%)的原料能生成较好的、大区域的中间相体,域结构的中间相体在外力导向和内部裂解气流的作用下容易生成有序的半焦,高温处理后呈大区域、片层紧密、有序性强的细纤维焦结构.同时研究发现,在热转化过程中可通过测定软化点(SP)和TI含量来确定中间相转化程度.软化点约低于250℃、TI为75%左右时为初始中间相区域体形成阶段、半焦生成的前期.
关键词:
煤沥青
,
热转化反应
,
喹啉不溶物
,
中间相
Q.S. Liu1
,
2
,
3)
,
L.C. Zhao3)
,
G.X. Dong2) and N.J. Gu1) 1) Heibei University of Technology
,
Tianjin 300130
,
China 2) Tianjin Institute of Technology
,
Tianjin 300191
,
China 3) Harbin University of Technology
,
Harbin 150001
,
China
金属学报(英文版)
Theconstruction changinginthereversetransformation ofthestress induced εMin Fe 17 Mn 10 Cr 5 Si 4 Ni alloy is carefully inspected in transmission electron microscope, and then stress induced εM procedure of reverse transformation is analyzed. The behavior of reverse transformationisdissimilar when the organization of εMis different. The reversetransfor mation ofεM withtheshapeofsingle plateandstripisrelativelyeasy,anditsreversibilityincrystallographiciseasilytocarryout,fortheεM with multilayerstructure,thereversetrans formationtakes placein isolatedlayers, fortheεMthat grows well,thereversetransforma tion isrelatively difficult becauseofthe ductile harmonization between itsinternalorganiza tion structures.
关键词:
stress induced εM
,
null
,
null
徐佩
,
卢旭鑫
,
汪传斌
,
杨善中
,
孙晓红
,
丁运生
高分子材料科学与工程
为改善多壁碳纳米管(MWNT)在低密度聚乙烯(LDPE)中的分散性及复合材料的界面特性,采用溴化-1-十六烷基-3-甲基咪唑基离子液体([C16min]Br)对MWNT进行表面改性,并用Raman光谱对改性效果进行了表征.将经过修饰的碳纳米管(MIL)与LDPE熔融共混得到MIL/LDPE复合材料,采用场发射扫描电子显微镜(FESEM)和阻抗分析仪(LCR)对复合材料的结构与介电性能进行了分析.结果表明,相比与MWNT/LDPE(渗流阈值为5.2％,介电常数为82,介电损耗为0.93),MIL/LDPE(渗流阈值为9.1％,介电常数为169,介电损耗为0.51)介电常数增大,介电损耗降低.并且在低温时,MIL/LDPE介电常数随温度的变化甚小,显示出良好的温度-介电常数特性.
关键词:
咪唑基离子液体
,
碳纳米管
,
低密度聚乙烯
,
介电性能
刘小红
,
王成扬
,
陈明鸣
,
于宝军
材料导报
以软化点相近的高软化点各向同性沥青和各向异性沥青为原料,经溶剂萃取分离出喹啉不溶物(QI),采用偏光显微镜、扫描电镜、元素组成分析、碘吸附测试和X射线衍射分析,对各向异性沥青的光学织构、QI的形貌及其微观结构进行了分析.结果表明,不同原料来源的各向异性沥青会表现出不同的光学各向异性.对高软化点沥青QI的分析表明,虽然母体沥青的软化点相近,但是具有不同光学各向性的沥青分离出的QI在形貌和微观结构上有较大的差异,各向异性沥青QI的分子交联度、芳香度和缩合度均比各向同性沥青QI小,但是平面分子结构更规整,有序度更高.同时发现,当沥青为各向同性时,母体沥青的分子有序度不如QI高,但当沥青为各向异性时,母体沥青的有序度却高于QI.
关键词:
各向同性
,
各向异性
,
高软化点
,
喹啉不溶物
陈登福
,
曾丁丁
,
潘艳华
,
董凌燕
,
罗敏
,
梁新亮
,
刘远岩
,
谢集祥
,
温德智
钢铁
建立了方坯高效连铸二冷数学模型,提出了喷嘴有效喷淋系数和二冷有效比水量的概念.依据二冷均匀冷却的思想,重新设计并优化了二冷喷淋结构和喷嘴的布置,增加了一个二冷喷淋段.提出了新的二冷水模型,即Qi=α+bv+cv2+d(△T-30)+F;二冷各段的喷水量与拉速、浇铸温度、钢水成分和二冷水温相关.实践证明,经优化后的二冷结构和二冷水模型合理,拉速大幅度提高,150mm×150mm断面的最高拉速达3.8～4.0m/min;铸坯质量明显改善;产量显著提高;经济效益非常显著.
关键词:
高效方坯连铸
,
二冷有效比水量
,
二冷水新模型
,
铸坯质量
