ZH Tu
,
Z Zhang
,
L.Z. Zhaoand T.X. Mao (Cryogenic Laboratory
,
Chinese Academy of Sciences
,
Beijing 100080
,
China) (Institute of Mechanics
,
Chinese Academy of Sciences
,
Beijing 100080
,
China )
金属学报(英文版)
The mechanical properties of a type of Al-alloy weld including strength, fracture tough-ness and ductility were comprehensively studied at different temperatures. The frac-ture behavior and weld micro features were also characterized. The surface crack test method was adopted to study the fracture toughness and a multiple specimen test ap-paratus was designed to perform the cryogenic experiments. The relationship between the mechanical properties and temperature was obtained together with the fracture toughness distribution in the weld.
关键词:
Al-alloy weld
,
null
,
null
,
null
Z Zhang
,
ZH Tu
,
L.F. Li
,
L.Z. Zhaoand D. Jin (Cryogenic Laboratory Chinese Acaderw of Sciences
,
Beijing 100080
,
China )H.J Lu (Beijing Institute of Aerospace Materials and Technology
,
Beijing 100076
,
China)
金属学报(英文版)
Low temperature may greatly affect the mechanical properties of materials. Some in-teresting mechanical phenomena were detected at very low temperature. In this study,a multi-sample tensile installation was designed to study the plastic deformation be-havior for Ti-5Al-2.5Sn extra-low-interstitial (ELI) alloy at liquid helium temperature.The special geometrical instability phenomena in low temperature, serrated deforma-tion and multi necking, was studied in detail in this project. Slip and twinning were determined in the process of plastic fiow by SEM/TEM analysis. Efficts of temper-ature and sequential straining on load drops in tensile stress-strain curves were also studied. Optical measurement method was used to gauge the geometrical characteristic of multi-necking specimens. The sensitivity of partial thermoplastic deformation and the equivalency of low tempemture with high velocity of this material were studied by using micro-mechanics analysis.The criterion of geometrical instability has been discussed. A computer simulation of the low temperature instability of plastic fiow in Ti-5Al-2.5Sn ELI alloy has been carried out. A computer model has been established which links the hot dtffusion and the plastic fiow of hcp alloys under assumption that the tempemture is homogeneous within the specimen and that the heat exchange with the thermal bath is the control-ling step in the heat release. The computer simulation of the deformation curves as a function of several mechanincal, geometrical and thermal parameters provides a re-alistic description of the experiments. The experimental data available are discnssed in the light of the computer simulation model.
关键词:
mechanical property
,
null
,
null
李佩
,
周世平
,
刘少斌
,
刘绍虎
,
陈丽华
,
王健
贵金属
doi:10.3969/j.issn.1004-0676.2010.03.003
采用轧制复合法制备AgCuNi/TU1复合带材,使用EDS能谱仪分析不同退火条件下复合界面元素的扩散情况,利用两端不受扩散影响的扩散偶模型和Arrenius关系计算退火温度在550～750℃下Ag在TU1中的扩散系数、扩散常数与扩散激活能.结果显示:退火温度在550～750℃之间,分钟级退火时间下(退火时间<5 min),AgCuNi/TU1复合界面主要发生表面原子扩散,且扩散系数和扩散常数在同一数量级,而扩散激活能有明显差别.
关键词:
金属材料
,
复合材料
,
扩散系数
,
扩散常数
,
扩散激活能
乔勋
,
王健
,
周世平
,
贺晓燕
,
李林修
贵金属
doi:10.3969/j.issn.1004-0676.2009.02.002
用室温固相轧制复合法制备了AgCuCe/TU1层状复合材料,研究了不同扩散退火工艺对AgCuCe/TU1界面结合性能的影响,测定了复合材料复层和基体的硬度,观察了试样的界面微观组织.结果表明:600 ℃/0.5 h扩散退火可以改善界面结合状态和界面附近组织形貌,获得充分的再结晶组织和致密的界面结合状态;700 ℃/0.5 h扩散退火在界面处形成细晶区和孔洞;750 ℃/0.5 h扩散退火使AgCuCe/TU1在界面处形成氧化物夹杂,严重损害界面结合性能.
关键词:
金属材料
,
复合材料
,
扩散退火
,
界面
,
显微组织
何晓英
,
邓海英
,
李容
腐蚀学报（英文）
doi:10.3969/j.issn.1002-6495.2005.04.007
采用交流阻抗法和极化曲线法研究了溴代十六烷基吡啶(CPB)和硫脲(TU)在复配前后对X70钢在H2SO3溶液中的缓蚀作用.研究发现:H2SO3的浓度为10 mmol/L、pH=3.7的HAc-NaAc缓冲体系中,溴代十六烷基吡啶(CPB)与硫脲(TU)的缓蚀率随着浓度的增加而增加,溴代十六烷基吡啶(CPB)的浓度达到5×10-6kg/L时的缓蚀性能最佳,而硫脲(TU)的浓度达到50×10-6kg/L时的缓蚀性能最佳.复配实验结果表明:当缓蚀剂的总浓度为25×10-6kg/L,溴代十六烷基吡啶(CPB)和硫脲(TU)复配质量浓度比为1:1时缓蚀效果最好.
关键词:
溴代十六烷基吡啶
,
硫脲
,
协同缓蚀
,
X70钢
,
电化学阻抗谱
刘少斌
,
王健
,
李佩
,
顾彬
,
卫思璇
,
周世平
贵金属
doi:10.3969/j.issn.1004-0676.2010.02.009
通过改变轧制道次变形量,制备AgCuNi/TU1复合材料样品.样品分剪后测量其侧弯度,利用XRD测定AgCuNi/TU1复合材料残余应力分布情况.结果表明:初始道次变形量对AgCuNi/TU1复合材料分剪后的侧弯度影响较大,在道次轧制压力基本相同的条件下,轧制的复合材料板形较好.基体有复层的部分残余应力为拉应力,而没有复层的部分残余应力为压应力,样品分剪后向有复层的一侧产生侧弯.
关键词:
复合材料
,
轧制道次变形量
,
残余应力
,
侧弯度
徐海娟
,
谢刚
,
袁靖淞
,
魏无际
材料保护
用乙二胺(EDA)和硫脲(TU)为原料制备缓蚀剂EDA-TU,优化了EDA-TU的合成条件.采用黏度法和红外光谱对合成产物的分子结构进行了表征.采用静态失重法和极化曲线法研究了其在氨法脱硫循环浆液中对Q235钢的缓蚀作用.结果表明:最佳的合成条件为合成温度80℃,反应时间4h,此时反应物的转化率最高;在氨法脱硫液中该缓蚀剂的用量为100 mg/L时,对Q235碳钢的缓蚀率可达75.16％;电化学分析表明该缓蚀剂对Q235碳钢的缓蚀作用是基于对阳极反应的抑制.
关键词:
乙二胺
,
缓蚀剂
,
氨法脱硫浆液
,
碳钢
Journal of Physical Chemistry C
Electrochemical measurements employing ac and dc techniques as well as atomic force microscopy were used to study the electrochemical corrosion behavior of ingot iron with two different microstructures: conventional polycrystalline ingot iron (CPII) and bulk nanocrystalline ingot iron (BNII) fabricated from CPII by severe rolling, without and with inhibitors. The corrosive media was 0.1 M H(2)SO(4) solution, while thiourea (TU) was employed as inhibitor, with a concentration of 5.0 mM, as well as a 1:1 combination of TU and KI. Impedance and polarization results show that BNII was more susceptible to corrosion in the uninhibited acid. The presence of TU improved the corrosion resistance of both specimens comparably, while KI reduced the inhibition efficiency of TU. Infrared spectrophotometry revealed that the interfacial species for CPII and BNII in the presence of TU were quite identical and markedly different from that in TU + KI. Molecular dynamics (MD) simulations were performed to illustrate the adsorption process of TU at a molecular level, and the theoretical predictions showed good agreement with the electrochemical results.
关键词:
nanocrystalline ingot iron;universal force-field;mild-steel corrosion;sulfuric-acid;electrochemical corrosion;sulfate-solution;behavior;thiourea;derivatives;molecules
