材料期刊网

INFLUENCE OF AUSTENITE STRENGTHENING ON MARTENSITIC TRANSFORMATION IN Fe-Mn-C ALLOYS

PAN Mu XU Zuyao (T.Y.Hsu) Shanghai Jiaotong University , Shanghai , China XU Zuy(T.Y.Hsu) , Professor , Dept.of Materials Science , Shanghai Jiaotong University , Huashan Road , Shanghai 200030 , China

金属学报(英文版)

The M_s temperature and the yield strength of austenite at M_s temperature have been meas- ured for five Fe-Mn-C alloys.The experimental results show that there is a linear relation- ship between them.The effect of the solution strengthening of austenite on martensite morphology is also studied.It is pointed out that there is a characteristic temperature T_c in austenite strengthening.Martensite morphology is mainly of dislocated laths when M_s>T_c, and is mainly of twinned plates when M_s<T_c.A theoretical analysis is given which is in good agreement with experimental results.

关键词: Fe-Mn-C alloy , null , null

T300与国产PAN基炭纤维的结构和性能研究

杨玉蓉 , 杨永生 , 华中 , 刘新

玻璃钢/复合材料 doi:10.3969/j.issn.1003-0999.2009.03.009

采用WARD、SAXS、RAMAN、XPS等测试技术对T300和国产聚丙烯腈基炭纤维(PAN-CF)的组织结构及化学组成进行了表征,分析了材料的微观组织结构与宏观性能的关系.结果表明,和T300相比,国产炭纤维的乱层石墨层间距d002略小,微晶尺寸La,Lc略大,微孔尺寸较大,大孔洞所占百分比较多,微孔含量较低.国产炭纤维表面含氧官能团含量较低,为31.35%.表面活性小.

关键词: PAN基炭纤维 , 组织结构 , 宏观性能 , 表面活性

STATISTICAL EVALUATION OF CRITICAL INCLUSION FACTOR FOR SECONDARY RECRYSTALLIZATON IN 3%Si STEEL Lecturer,Department of Materials Engineering,Southwestern Jiaotong University,Chengdu 610031,China

LI Shuchen Southwestern Jiaotong University , Chengdu , ChinaCHEN Mengzhe KE Jun University of Science and Technology Beijing , Beijing , China

金属学报(英文版)

On the basis of statistical data of MnS in the conventional 3% Si steel sheeets after various annealing processes,the critical inclusion factor has been evaluated to be 20 mm~(-1).The inhi- bition of MnS to grain growth has been exactly described.

关键词: 3%Si steel , null , null

基于(火积)耗散率最小的T-Y形肋片构形优化

冯辉君 , 陈林根 , 谢志辉 , 孙丰瑞

工程热物理学报

基于构形理论,以导热和对流换热总(火积)耗散率最小为优化目标,对T-Y形肋片进行构形优化,得到同时考虑导热和对流换热(火积)耗散性能的T-Y形肋片最优构形.结果表明:存在最佳单元级直肋和中部空腔高度和长度比使得T-Y形肋片无量纲当量热阻取得二次最小值.增大肋片高度和长度比和肋片占比有助于提高T-Y形肋片整体传热性能.T-Y形肋片与T形肋片相比,T-Y形肋片二次最小无量纲当量热阻降低32.33％,此时T-Y形肋片温度梯度场更均匀,整体传热性能得到明显提高.

关键词: 构形理论 , (火积)耗散率最小 , T-Y形肋片 , 对流换热 , 广义热力学优化

Huazhong University of Science and Technology(H.U.S.T)

材料科学技术（英文）

关键词:

PAN基炭纤维经济规模分析

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 , 经济规模 , 工程技术法

Effect of stress on mu phase formation in single crystal superalloys

Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing

Precipitation behavior of the mu phase under applied stress was systematically investigated in two single crystal superalloys CMSX-4 and R0. The investigation has shown that both the sign and magnitude of the applied stress can affect the precipitation behavior of the mu phase with a certain degree of regularity. At first, the precipitation of the mu phase varied significantly when a small amount of stress was applied, regardless of whether the specimen is under tension or under compression. Under most conditions however, precipitation of the mu phase was restrained by this low application of stress. After increasing the applied stress, precipitation of the mu phase increased relative to the amount of tension or decreased under compression. (C) 2010 Elsevier B.V. All rights reserved.

关键词: Single crystal superalloy;Topologically close-packed (TCP) phase;Thermal exposure;Rhenium (Re);kinetics;cmsx-4

Investigation of glass formability in Al-Co-Y ternary system

材料科学技术（英文）

The glass formation was investigated in the melt-spun AI-rich Al-Co-Y alloys by the microstructure evolution. The best glass former Al88Co5Y7 with the thickness of 230 mu m was found, and its glass forming ability (GFA) was higher than that of previously reported Al88Co4Y8 alloy. This result indicates that GFA is strongly sensitive to the alloy composition in the system. The phase selection method is an effective way to locate the optimum glass formation composition rather than T-rg and Delta T-x parameters.

关键词: Al amorphous alloy;microstructure evolution;glass forming ability;supercooled liquid;metallic glasses;amorphous-alloys;ni;la;science

A mu-Phase behavior in a cast Ni-base superalloy

Journal of Materials Science

The response of mu phase to applied stress and long-term thermal exposure has been investigated in the cast Ni-base superalloy K446. It is found that during stress rupture, the applied stress accelerates the precipitation and growth of mu phase. However, during thermal exposure the mu phase precipitating in the form of needles and granules experiences a complicated evolution. The needles, fiber- or sheet-shaped in three-dimension, align very regularly during exposure, either lying in three directions with an acute angle to one another or in two directions perpendicular to each other, the mechanisms of which are characterized in detail. In addition, it is concluded that an excessive precipitation of mu phase severely degrades the mechanical properties of the alloy, whereas its evolution behavior during thermal exposure is determined to have an insignificant influence on the properties.

关键词: single-crystal superalloy;thermal exposure;precipitation;stability;rupture;stress

AA6061-T6铝合金表面纳米Y2 O3改性硅烷膜的耐蚀性

张明明 , 李文超 , 张圣麟

腐蚀与防护

采用动电位极化曲线，电化学阻抗谱（EIS）和中性盐雾试验（NSS）研究了溶液中加入不同含量纳米Y2 O3对铝合金AA6061-T6表面硅烷膜耐蚀性的影响，采用扫描电镜（SEM）对其形貌进行了观察。结果表明，在1，2-双-三乙氧基硅烷（BTSE）溶液中加入少量纳米Y2 O3可提高硅烷膜在3．5％ NaCl溶液中的耐蚀性。硅烷膜对铝合金的保护只起到物理屏障作用。纳米Y2 O3抑制了电化学腐蚀过程中阴极还原反应的发生，但不影响电极反应的动力特征。SEM表明在BTSE硅烷溶液中添加10～20 mg/L的纳米Y2 O3后，硅烷膜表面变得平滑致密。

关键词: 硅烷膜 , 纳米Y2 O3 , 耐蚀性能 , 铝合金