W.Q. Zhang
,
Q.M. Liu
,
Y.F. Zhu
,
Y.S. Yang and Z.Q. Hu(State Key Laboratory of RSA
,
Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China)
金属学报(英文版)
An investigation on electromagnetically-stirred solidification of Al-CuAl2 eutectic system is presented in this paper. With electromagnetic stirring in solidification, structural transition from lamellar to rod-like eutectic has been found in the as-cast structures, and provided strong stirring is applied, proeutectic growth of α-Al phase is enhanced. Moreover, the interphase spacing of eutectic is clearly increased with melt flow intensified. Numerical computation of flow field is also presented, and the effect of stirring on structural formation is discussed.
关键词:
electromagnetic stirring
,
null
,
null
,
null
W.Q. Zhang
,
Y.F. Zhu
,
Y.S. Yang and Z.Q. Hu (State Key Lab. of RSA
,
Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China)
金属学报(英文版)
The effects of magnetic field on macro and microstructure of Al-CuAl2 eutectic alloy produced by electromagnetic centrifugal casting have been erperimentally investigated in the present paper. Electromagnetic stirring can lead to columnar formation in the cuter region and equiaxed in the inner, and otherwise cause the lamellae coarsened and the microstructure morphology to change from lamella to rod and then to block,if the electromagnetic stirring is intensified.
关键词:
electromagnetic stirring
,
null
,
null
Journal of Materials Research
The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.
关键词:
room-temperature
田兆硕
,
李自勤
,
王骐
,
王雨三
量子电子学报
doi:10.3969/j.issn.1007-5461.2002.04.003
本文研究了CdTe电光调Q晶体及电光调频晶体的调制特性,报道了采用CdTe电光调频晶体进行电光调Q的光栅选支射频激励波导CO2激光器,调Q激光脉冲重复频率1 Hz～10 kHz可调,在10 kHz重复频率时,获得激光脉冲峰值功率为300 W,脉冲宽度为150 ns.
关键词:
电光调频晶体
,
电光调Q
,
射频波导CO2激光器
夏金魁
,
李相付
,
曹龙琼
,
黄道昌
,
陈敏明
连铸
doi:10.13228/j.boyuan.issn1005-4006.20150143
在降本增效的背景下,炼钢厂生产Q235B连铸板坯时,进行了成分优化和工艺流程简化,按照新工艺生产后,Q235B连铸板坯出现较多内部裂纹.经数据统计、低倍检验和扫描电镜分析后表明,Q235B连铸板坯产生内部裂纹主要是由钢水脱氧不良、夹杂物含量高,拉速和二次冷却控制不合理等原因造成,通过深脱氧、延长氩站软吹氩时间及降低浇铸速度等措施,新工艺在w[Mn]/w[S]≤30条件下,Q235B连铸板坯内部裂纹发生率降至原工艺水平.
关键词:
脱氧
,
吹氩
,
拉速
,
二次冷却
刘建容
,
张万灵
,
蔡捷
,
石争鸣
,
陈吉清
腐蚀与防护
对武钢生产的W450QN钢进行了3年的大气暴露试验,结果表明,W450QN钢的耐蚀性优于Q345钢,在青岛站、江津站、琼海站,W450QN钢与Q345钢相比,平均腐蚀速率之比分别为1:1.48,1:1.45,1:1.44.带锈样的极化曲线测试结果显示,W450QN钢的致钝电流密度、维钝电流密度均比Q345钢小,说明其锈层致密、传质能力差,所以防护性能好.
关键词:
耐候钢
,
大气腐蚀
,
锈层
HUANG Huimin CHEN Xinmin Central South University of Technology
,
Changsha
,
China HUANG Huimin Associate Professor
,
Department of Chemistry
,
Central South University of Technology
,
Changsha
,
China
金属学报(英文版)
The nature of the oxygen contained in β-W was investigated with DSC,X-ray analysis on quenched samples and Auger spectroscope.It was shown that the oxygen contained in nonpyrophoric β-W consists of the reversibly chemisorbed oxygen and the interstitial oxygen which could form an interstitial solid solution with β-W.It seems better to consider β-W to be a metastable phase of tungsten with the interstitial oxygen as stabilizer.
关键词:
tungsten
,
null
,
null
,
null
周哲
,
陈国梁
,
许立新
,
顾春
,
赵威
连铸
doi:10.3969/j.issn.1007-5461.2016.05.005
利用Mach-Zehnder (M-Z)结构的尾纤型铌酸锂(LiNbO3)电光强度调制器作为主动调Q开关元件,采用974 nm半导体激光器作为泵浦源,峰值吸收系数为110 dB/m的掺杂铒光纤作为增益介质,实现了1550 nm波长的全光纤主动调Q激光器.通过电光强度调制器对腔内损耗进行了周期性调制,实现Q开关作用,获得了稳定的调Q脉冲输出.通过改变泵浦功率和调制频率研究了脉冲宽度和峰值功率的变化规律,调制频率在50 Hz～88 kHz内调整时可以得到稳定输出脉冲.调制频率为1 kHz时获得最窄脉冲宽度246 ns,峰值功率近5W.
关键词:
激光技术
,
主动调Q
,
Mach-Zehnder电光调制器
,
多峰现象
