Shanling WANG
,
Baoluo SHEN Shengji GAO
,
Da LI
,
Mingjing TU
,
Weicheng YU
,
Ge YAO
材料科学技术（英）
The creep behavior of Al2O3. SiO2 fiber reinforced ZL109 composites has been investigated at four temperatures ranging from 553 to 623 K. The results show high stress exponent and high apparent creep activation energy. A good correlation between the normalized creep rate and normalized effective stress means that the true stress exponent of minimum creep strain rate of the composite is very close to 5, and the minimum creep strain rate is matrix lattice diffusion controlled. The threshold stress decreases with increasing temperature linearly and disappears at a temperature close to 623 K. It is assumed that the long range internal back stresses generated in creep reduce the load transfer to fibers and the interaction between dislocations and strengthening precipitates decreases at high temperature. At a high temperature where the long range internal back stresses is very close to the applied stress, the threshold stress disappears.
关键词:
Quan'an LI
,
Yungui CHEN
,
Mingjing TU
材料科学技术（英）
Effect of stoichiometry on microstructures, electrochemical properties and PCT characteristics of the alloys Ml(Ni0.71Co0.15-Al0.06Mn0.08)x (Ml=Lanthanum-rich Michmetal, x=4.6-5.2) have been investigated. The lattice constants a, c and cell volumes of non-stoichiometric alloys are bigger than those of the stoichiometric alloy. With the increasing stoichiometry x, the value of a decreases, and the value of c and cell volume increases except for those of the stoichiometric alloy; the plateau pressure of PCT curve, discharge capacity and cycling stability all increase. The alloy with x=5.2 shows the highest discharge capacity and the best cycling stability among the studied alloys.
关键词:
Hydrogen storage alloy
,
null
,
null
,
null
,
null
Yuhua WEN
,
Ning LI
,
Mingjing TU
材料科学技术（英）
The effects of prestrain and annealing temperature on phase transformation temperatures in Fel4Mn5Si8Cr4Ni shape memory alloy have been studied. The results showed that when the annealing temperature was 673 K, both the A(f) and the M-s temperatures increased appreciably as the prestrain increased, the A, temperature increased slightly with increasing prestrain, the resistivity difference at 303 K between the heating and cooling curve also increased with increasing prestrain, which agreed with the recovery strain. The shape memory effect in Fe-Mn-Si-Cr-Ni shape memory alloy is caused by the stress-induced gamma --> epsilon martensite transformation and its reverse transformation. When the prestrain was 10%, the M-s temperature decreased remarkably as the annealing temperature increased.
关键词:
Yuhua WEN
,
Ning LI
,
Mingjing TU
材料科学技术（英）
The effects of aging temperature on shape memory effect, mechanical properties and microstructure of Fe-14Mn-5Si-8Cr-4Ni-0.2C shape memory alloy have been studied. The results showed that the second phase particles rich in chromium, manganese and silicon precipitate during aging, and thereby increase the hardness and strength of the alloy. The shape recovery ratio can be remarkably improved by aging and a maximum value can be obtained at 1223 K, which is 68% higher than that of the specimen in solid solution state. When the aging temperature is below 1223 K, the amount of second phase particles increases as the aging temperature increases. The size of austenite grain increases with increasing aging temperature. When the temperature is over 1223 K, the second phase particles can not precipitate. The lack of second phase particles and the increase of grain size make the hardness and shape recovery ratio drastically decrease, when the temperature is over 1223 K.
关键词:
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
腐蚀科学与防护技术
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
