韩青有
金属学报
颗粒推斥（Ｐａｒｔｉｃｌｅｐｕｓｈｉｎｇ）是材料在固液相变过程中的基础问题之一．界面自由能的传统理论难以解释在金属基复合材料制备过程中的颗粒推斥现象。作者提出固液界面前沿的流体流动是颗粒推斥的主要原因之一，并给出颗粒滚动及颗粒速度两种作用机制，推导出颗粒推斥条件判据，并以实验验证流体流动的作用机制及颗粒推斥理论判据．实验结果与理论模型吻合。
关键词:
颗粒推斥
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solidification
,
fluid flow
何毅
,
范毅
,
丁忆鑫
,
罗智
腐蚀科学与防护技术
doi:10.11903/1002.6495.2014.069
实验模拟了油、气集输过程碳钢管线中的流体环境,在不同流体速度、温度及成膜时间下,通过EIS技术考察45号钢表面附着缓蚀剂膜的耐腐蚀性能及破坏过程.缓蚀剂膜的腐蚀破坏过程中,EIS监测获得典型的电化学阻抗谱.结果表明,随着腐蚀时间、流体流速与流体温度的增加,碳钢表面附着缓蚀剂膜层由厚变薄,由致密变疏松,并表现出多孔性.因此,流体通过导致的表面剪切作用与气泡冲击,降低了该缓蚀剂的性能表现.通过SEM方法,辅助评价了处于不同状态下的缓蚀剂膜的结构.
关键词:
缓蚀剂
,
膜层
,
流体
,
碳钢
,
电化学阻抗谱
S. W Ma
,
J.C
,
He and H.S. Di 1) School of Materials and Metallurgy
,
Northeastern University
,
Shenyang 110006
,
China 2) The State Key Laboratory of Rolling and Automation
,
Northeastern University
,
Shenyang 110006
,
China
金属学报(英文版)
In this paper three-dimensional flow field in the molten pool between unequal diameter twin rolls has been studied by BFC technology and SIMPLEC numerical method. From the computed flow pattern,the characteristic of molten steel flow has been discussed. The dynamics generated by the feeding flow and the motivation of counter-rotating twin rolls produces a recirculating flow field nearby the small roll due to the larger room and less resistant here and fluid flows along the roll surface tangential nearby large roll and extends to two side dams. There is faintly flow around the dams of molten pool
关键词:
NNSCC
,
null
,
null
,
null
,
null
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
