黄卫东
,
王旭洪
,
王莉
,
盛玫
,
徐立强
,
Frank Stubhan
,
罗乐
腐蚀学报（英文）
doi:10.3969/j.issn.1002-6495.2004.05.007
测量了在FR4基板上用引线键合和顶充胶封装的湿度传感器在无防护、氮化硅薄膜防护、硅酮涂层防护、硅酮涂层加氮化硅薄膜防护四种情况下及在不同温湿度环境下的水汽扩散曲线.应用有限元分析和FICK扩散方程模拟了实验曲线,得到了水汽在各种防护条件下的扩散系数,进而计算出水汽扩散的激活能,定量比较了各种防护方法的效果.实验和模拟结果表明:硅酮加氮化硅薄膜的双层防护可以显著改善电子模块的防水性能.
关键词:
塑料封装
,
湿度传感器
,
水汽扩散
,
有限元分析
朱满
,
杨根仓
,
刘峰
,
程素玲
,
杨伟
,
万迪庆
,
周尧和
中国有色金属学报
Frank-Kasper相Mg32(Al,Zn)49是与其准晶相相对应的1/1近似相,它具有二十面体壳层密堆结构.研究了在常规凝固条件下化学成分为AlxMg40Zn60x(x=20～45,摩尔分数)合金中Frank-Kasper相的组织形貌.利用光学显微镜、X射线衍射仪及扫描电镜,确定了Frank-Kasper相的组织及成分.结果表明:AlxMg40Zn60-x(x=20～45)合金中均为单相的Frank-Kasper相;随铝含量的增加,其形貌由花瓣状逐渐向"十字架"状组织转变.
关键词:
Al-Mg-Zn合金
,
Frank-Kasper相
,
二十面体密堆结构
,
组织形貌
Acta Metallurgica Et Materialia
A new group of Frank-Kasper phases has been observed in Al Li-Cu-Mg alloys using high resolution electron microscopy (HREM). The Y phase, which has a face-centre cubic structure with a = 2.0 nm, occurs in grain boundaries during precipitation heat treatment of supersaturated solid solution. Considerable amount of intrinsic faults, extrinsic faults and microtwins were observed in the Y phase. A new domain denominated as D intergrowth with Y phase along {111} planes has been found. By combination of Y phase and D domain, new domains can be constructed.
关键词:
juxtaposed pentagonal antiprisms;close-packed phases;domain-structures
余勇
,
潘晓霞
金属学报
doi:10.3321/j.issn:0412-1961.2009.11.006
为了在细观尺度上更好地模拟Frank-Read(FR)位错源的演化,本文改进了三维(3D)离散位错动力学模型中相邻位错段间作用力计箅方法和位错线的离散化方法.模拟结果表明,所改进的位错动力学模型能更准确地模拟不同初始长度的FR位错源的临界剪切应力和临界组态.并且加载应力越大,FR位错源形成的位错环越小,并逐渐接近不考虑位错段间相互作用力时所形成的位错环.在相同加载应力时,Peierls应力越大,形成的位错环也越大.阻尼系数只影响位错环形成的时间,而不影响形成的大小.位错的这种非线性演化方式,是位错段间存在相互作用力引起的.
关键词:
Frank-Read位错源
,
位错动力学模型
,
细观级模拟
J.G WanG
,
L.C Zhang
,
G.L. Chenand HQ. Ye(State Key Laboratory for Advanced Metals and Materials
,
Unborsity of Science and Technology Beijing
,
Beijing 100083
,
China)(Laboratory of Atond Imaging of Solids
,
Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China)
金属学报(英文版)
The dislocation ledges at the α2/7 intedece in a hot-dejormed Ti-45Al-10N alloywere analyzed by high-resolution tmnsmission electron microscopy. A new type ofdislocation ledge containing 1/3[111] Frank partial was found. The height of the ledgestDas always three [111]γplanes. The Burpers vectore of these diBlocation ledges weredetermined to be 1/2[110] and 1/2<101] corresponding to the 90 dey. and 30 deg.Shockley partials at noral ledges, i.e. 90 dep. ShockIey Partial dislocation +1/3[111]Frank partial dislocation; and 30 deg. Shockley partial dislocation + 1/3[111] Frankparfial dislocations. The jormation mechanism of this new tare of dislocation ledgewas discussed.
关键词:
titanium aluminide
,
null
,
null
,
null
Philosophical Magazine a-Physics of Condensed Matter Structure Defects and Mechanical Properties
Networks of the {110} shear plane family in the Al5CuLi3 crystal structure have been observed during the phase transformation from AlCuLi icosahedral phase to the crystalline phase, i.e. Al5CuLi3 crystal. HREM images of the shear planes are reported along both [111] and [001] directions which establish the shear vectors uniquely. Structural models for the shear planes, intersection areas and translation domains have been symmetrically proposed and are in good agreement with experiments.
关键词:
