郑劼
,
朱霞萍
,
李品
,
白德奎
,
李铭
功能材料
doi:10.3969/j.issn.1001-9731.2016.09.045
共沉淀法制备了C u-Mg-A l层状超分子化合物,X 射线衍射图谱和热重分析表征了材料的结构,并研究了材料对溶液中碘离子的吸附去除性能.制备的材料为具有层状结构的 C u-Mg-A l 的超分子化合物,具有结构“记忆效应”,层间可以吸附碘,层板上的铜对碘也有特异化学作用,增强材料对碘的吸附能力.在优化制备和吸附条件下,Cu-Mg-Al层状超分子化合物对碘离子的饱和吸附量为279．15 mg/g,远高于普通层状氢氧化镁铝的66．61 mg/g.材料可作为碘及放射性碘污染的吸附去除剂.
关键词:
层状金属氢氧化物
,
超分子
,
铜
,
碘
,
去除
陈树东
,
项建明
,
王晓翠
,
洪笑
硅酸盐通报
以Ca(OH)2、SiO2、Fe2O3、Al2O3化学纯为原料,分别掺入不同质量分数的Ba(OH)2制备不同矿物相组成的熟料相,运用化学分析、XRD、SEM、水化热测试方法,研究掺Ba(OH)2后熟料相中硅酸三钙-硅酸二钙(C3S-C2S)混合相组成、晶型、新相生成的变化规律.结果表明:Ba(OH)2一定程度上削弱C3S形成,且稳定β-C2S形成效应明显,矿物相体系中α'-C2S、α-C2S量减少并转换为β-C2S,掺量大于2.5％后有新相Ba0.48 Ca1.52SiO4形成;Ba(OH)2掺入促使矿物相中C2S相明显增多,晶粒整体尺寸变小,边界变圆润;随Ba(OH)2掺量递增,熟料样的水化速率呈持续减小的趋势变化.
关键词:
C3S相
,
β-C2S
,
水化速率
,
水化
D.Han
,
S.R.Qiao
,
M.Li
,
J.T.Hou
,
X.J.Wu
金属学报(英文版)
The differences of tension-tension fatigue and tensile creep characters of 2D-C/SiC and 3D-C/SiC composites have been scrutinized to meet the engineering needs. Experiments of tension-tension fatigue and tensile creep are carried out under vacuum high temperature condition. All of the high temperature fatigue curves are flat; the fatigue curves of the 2D-C/SiC are flatter and even parallel to the horizontal axis. While the tension-tension fatigue limit of the 3D-C/SiC is higher than that of the 2D-C/SiC, the fiber pullout length of the fatigue fracture surface of the 3D-C/SiC is longer than that of the 2D-C/SiC, and fracture morphology of the 3D-C/SiC is rougher, and pullout length of the fiber tows is longer. At the same time the 3D-C/SiC has higher tensile creep resistance. The tensile curve and the tensile creep curve of both materials consist of a series of flat step. These phenomena can be explained by the non-continuity of the damage.
关键词:
2D-C/SiC
,
null
,
null
Hejun Li
材料科学技术（英）
2D needle-punched fiber felt was infiltrated by a kind of rapid isothermal chemical vapor infiltration technique.
The infiltration process and texture transition of the infiltrated C/C composites were investigated. The porosity
and the variations of the cumulative pore volume were determined by mercury porosimetry. The texture of
matrix carbon was studied under a polarized light microscope. The results show that the relative mass gain
of the sample increases directly as the infiltration time at the initial stage until 20 h, and subsequently the
increasing rate of the relative mass gain decreases gradually with the prolonging of infiltration time. Three layers
of pyrocarbon were formed around fibers. Low-textured pyrocarbon was obtained at the initial stage. With the
densification going on, high-textured pyrocarbon was formed on the surface of low-textured pyrocarbon. Then,
low-textured pyrocarbon was produced again during the final stage of densification. The texture transition is
ascribed to the variation of the ratio of cumulative inner surface area to volume of pores and the gas partial
pressure in pores.
关键词:
C/C composites
,
Isothermal chemical vapor infiltration (ICVI)
,
Pyrocarbon
,
Mercury porosimetry
,
Polarized light microscope
郭志军
,
周建军
,
钟彦平
,
张玉福
,
吴学纲
材料保护
NK-HITEN610U2钢板已在我国用于液态烃球罐,由于液体烃中常含有水分和硫化氢,该材料在湿硫化氢环境中的耐蚀特性尚不明确.对采用回火焊道的焊接接头,经恒负荷拉伸、恒应变、焊接约束试板、氢诱导开裂、断裂韧性等试验和断口分析,对该钢板及其焊接接头在湿硫化氢环境中的抗H2S应力腐蚀开裂(SSC)性能进行了系统研究.发现其因母材中存在夹杂物偏析而对氢诱导裂纹(HIC)敏感,未经热处理的焊接接头,临界开裂应力指数Sc值小于10,材料在H2S介质中的临界应力强度因子KISCC值38 MPa·m-1/2,对SSC有一定的敏感性,认为用该材料在湿硫化氢环境中存在发生SSC的危险.据此,提出了球罐的检验和监控措施.
关键词:
球罐
,
NK-HITEN610U2钢
,
SSC
,
焊接接头
芦令超
,
常钧
,
沈业青
,
程新
,
刘韩星
,
袁润章
硅酸盐通报
doi:10.3969/j.issn.1001-1625.2005.02.023
研究了B2O3和CaF2对C3S-C2.75B1.25A3S-C2S-C3A熟料矿物体系的组成、结构与力学性能的影响.研究结果表明:在该熟料体系中C3S,C2.75B1.25A3S,C2S和C3A的适宜含量分别为50%,10%,25%和15%,B2O3和CaF2的适宜掺量为2%和1.5%.在最佳组成和制备工艺条件下,合成的阿利特-硫铝酸钡钙水泥的1d,3d和28d抗压强度分别达到18MPa,48MPa和95MPa以上,展现了良好的早期力学性能.同时,掺加CaF2能有效降低熟料中游离氧化钙的含量,促进阿利特在低温条件下形成.利用SEM-EDS,XRD等测试手段对熟料的组成、结构及性能进行了分析.
关键词:
阿利特 硫铝酸钡钙 B2O3 CaF2
