H.T.Shaban
,
M.M.Nassary
,
M.S.El-Sadek
材料科学技术（英文）
Bi2S3 single crystals were grown by using a modification of Bridgman method. Measurements of the electrical conductivity, Hall effect and thermoelectric power (TEP) were preformed in two crystallographic directions (parallel and perpendicular to the c-axis). The measurements showed that the electrical conductivity, Hall mobility, and Seebeck coefficient have anisotropic nature. From these measurements some physical parameters were estimated and the crystals showed n-type of conduction mechanism. Also, values of the energy gap were found to be different in the two directions.
关键词:
Bi2S3
,
null
,
null
,
null
井敏
,
谭婷婷
,
王成国
,
冯志海
,
杨云华
,
潘月秀
材料科学与工艺
doi:10.11951/j.issn.1005-0299.20150208
东丽T800H和T800S是分别采用湿纺和干湿纺制备的两种力学性能相近的碳纤维，为弄清不同纺丝方法对T800级碳纤维微观结构的影响，采用扫描电镜、X射线衍射仪、小角X射线散射仪和高分辨透射电镜对这两种碳纤维进行测试，比较其表面形貌、断口形状和形貌、石墨微晶结构和微孔结构等．研究结果表明，湿纺制备的T800H比干喷湿纺制备的T800S的表面粗糙、断口圆度差、原纤尺寸较大、石墨微晶致密度差且发育不完善、内部微孔尺寸大、石墨微晶条带韧性差，这正是T800H的拉伸强度和断裂伸长率不如T800S的重要微观结构因素，但T800H的石墨微晶取向度不如T800S，孔隙率略高于T800S．
关键词:
碳纤维
,
微观结构
,
力学性能
,
表面形貌
,
孔结构
,
石墨微晶
王迎芬
,
彭公秋
,
李国丽
,
谢富原
,
刘勇
材料科学与工艺
doi:10.11951/j.issn.1005-0299.20150420
为了研究T800H碳纤维的表面特性及其与BA9918树脂的界面匹配性，分别采用SEM、AFM、XPS和TGA对T800H碳纤维表面形貌、表面化学特性以及碳纤维上浆剂热稳定性进行表征，测试了T800H／BA9918复合材料湿热处理前后0°压缩强度、90°拉伸强度和层间剪切强度，并得到了其在湿热处理前后的开孔压缩和冲击后压缩性能。测试发现T800H碳纤维表面有明显的沟槽，有利于表面机械啮合作用；T800H／BA9918复合材料经29 J能量冲击后压缩强度为314 MPa；在130℃湿态环境下其0°压缩强度和层间剪切强度保持率高于58％，开孔压缩强度保持率高于60％。试验结果证明T800H碳纤维与BA9918树脂具有良好的界面匹配性，T800H／BA9918复合材料具有优异的耐湿热性能。
关键词:
T800H碳纤维
,
复合材料
,
力学性能
,
湿热处理
李新梅
,
张忠文
,
邹勇
,
杜宝帅
,
邹增大
材料导报
根据新型耐热钢T92和Super304H钢的焊接特点制定了适宜的焊接工艺,研究了焊制的T92/Super304H异种钢焊接接头的力学性能.结果表明,T92/Super304H异种钢接头的各项力学性均能满足使用要求.焊缝金属的韧性远低于T92钢侧热影响区,焊缝金属的结晶形态对焊缝韧性有很大的影响.焊接接头中焊缝金属的硬度值最高,而T92钢侧热影响区硬度最低,并且不同热影响区部位显微硬度变化较大,Super304H钢侧热影响区硬度变化不大.
关键词:
T92钢
,
Super304H钢
,
新型耐热钢
,
异种钢
,
焊接接头
Huijie LIU
材料科学技术（英文）
The friction stir weldabilities of the strain-hardened AA1050-H24 and precipitate-hardened AA6061-T6 aluminum alloys were examined to reveal the effects of material properties on the friction stir welding behavior. The experimental results are obtlained. (1) For AA1050-H24, the weld can possess smoother surface ripples; there is no elliptical weld nugget in the weld; there is no discernible interface between the stir zone and the thermomechanically affected zone; and the internal defect of the weld looks like a long crack and is located in the lower part of the weld. (2) For AA6061-T6, the weld usually possesses slightly rougher surface ripples; an elliptical weld nugget clearly exists in the weld; there are discernible interfaces among the weld nugget, thermomechanically affected zone and heat affected zone; and the internal defect of the weld is similar to that of the AA1050-H24 weld. (3) The effective range of welding parameters for AA1050-H24 is narrow, while the one for AA6061-T6 is very wide. (4) The maximum tensile strength efficiency of the AA1050-H24 joints is similar to that of the AA6061-T6 joints, i.e. 79% and 77%, respectively.
关键词:
Friction stir weldability
,
null
,
null
,
null
李朝阳
,
马贵阳
,
朱本光
,
乔伟彪
,
杜明俊
腐蚀与防护
在原油管输过程中，液相介质内常含有一定量以H2S为主的酸性气体，这些气体具有极强的腐蚀性，常引发管道内壁不均匀腐蚀或点蚀，从而发生泄漏事故。通过对T形管内气液两相流的研究发现，两相介质在分支处的分布总是不均匀的。利用CFD软件对T型管道内原油与H2S气液两相流动进行了数值模拟，得到了稳定状态下管道中H2S的分布规律。结果表明，原油流经T型管道时，会在支管口背流处生成稳定H2S高浓度区；原油流速越大硫化氢浓度变化越大；速度的变化对硫化氢高浓度分布区的范围影响不大。为管道腐蚀防护、确保管道安全稳定运行提供了理论依据。
关键词:
T型管道
,
硫化氢
,
数值计算
叶飞
,
张文征
,
张驰
,
齐彦
,
方鸿生
金属学报
doi:10.3321/j.issn:0412-1961.2000.07.001
介绍了获得满足△9平行法则的位向关系、惯习面、正空间和倒空间准不变应变线的计算方法,解释了高锰钢中先共析魏氏组织渗碳体在奥氏体晶内析出时的Pitsch和T-H位向关系.计算得到的位向关系和惯习面结果与实验结果吻合得很好.根据计算结果,将惯习面分解成原子级的台阶,绘制了Pitsch和T-H位向关系惯习面上的晶格匹配示意图.
关键词:
△9平行法则
,
相变
,
晶体学
,
界面
,
结构模型
