燃料电池用LSGM-碳酸盐复合电解质材料的稳定性

目前研究较多的固体氧化物电池用碳酸盐复合电解质体系中,碳酸盐在工作温度下的熔融状态使其稳定性受到质疑。本文通过聚丙烯酰胺溶胶凝胶法制得La0.9Sr0.1Ga0.8Mg0.2O2.85（LSGM）粉体与二元碳酸盐复合,制备了新型LSGM-碳酸盐复合电解质,从老化、循环和电池输出三方面考察了LSGM- (Li/Na)2CO3复合电解质的稳定性。在600℃、650 h的测试中,复合电解质的电导率长期稳定在0.07~0.09 S?cm-1;在室温~700℃循环中碳酸盐基本没有损失,电导率也较稳定;单电池在0.6 A?cm-2恒流放电,1 h内平均功率密度为256 mW?cm-2。     

核电压力容器SA508-3钢内部裂纹高温焊合实验

裂纹缺陷严重影响大型锻件的合格率及使用寿命。为保证核电大型锻件质量、提高核电压力容器安全性,以加热温度、下压量以及保压时间为参数,采用预置裂纹方式对核电压力容器用钢SA508-3进行内部裂纹高温焊合实验研究。裂纹焊合效果采用金相显微镜、扫描电镜、能谱分析及力学性能实验等进行评价。结果显示,在高温短时间小变形情况下SA508-3材料内部裂纹均能焊合,裂纹焊合最低条件为:加热温度1100℃,变形量10%,保压时间15 s;焊合后试样强度值与基体相似,但塑性值有较大波动;根据扫描电镜及能谱分析确定,试样连接过程中带入的大量夹杂物是材料塑性指标波动较大的主要原因。     

Fabrication of hexagonal gallium nitride films on silicon (111) substrates

Hexagonal gallium nitride films were successfully fabricated through ammoniating Ga2O3 films deposited on silicon (111) substrates by electrophoresis. The structure, composition, and surface morphology of the formed films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The measurement results reveal that the polycrystalline GaN films with hexagonal wurtzite structure were successfully grown on the silicon (111) substrates. Preliminary results suggest that varying the ammoniating temperature has obvious effect on the quality of the GaN films formed with this method.     

Mo—La2O3烧结坯间隙杂质的研究

通过扫描电镜（ＳＥＭ）、电子探针（ＥＰＭＡ）、Ｘ射线衍射（ＸＲＤ）及俄歇电子能谱（ＡＥＳ）研究了Ｍｏ－Ｌａ２Ｏ３烧结坯中的间隙杂质。结果表明：Ｌａ２Ｏ３的加入提高了烧结睛坯的抗弯强度和韧性。间隙杂质不驻存在于Ｍｏ中,而且在Ｌａ２Ｏ３粒子表面吸附,使晶界杂质浓度降低。     

合金元素Ga对Sn-9Zn无铅钎料性能的影响

研究了合金元素Ga的添加量对Sn-9Zn无铅钎料熔化特性、润湿性能及其焊点力学性能的影响.结果表明,添加合金元素Ga以后,合金的熔点显著降低,熔化温度区间有所增大,润湿性能得到明显改善;合金元素Ga的添加量(质量分数)在0.5%时,钎料的晶粒组织最为细小均匀,钎料焊点的力学性能最佳;当合金元素Ga的添加量大于1%时,钎料的润湿性能趋于稳定,钎料组织中晶界处出现黑色富Ga相,钎料焊点的力学性能大幅度降低.因此,Sn-9Zn无铅钎料中合金元素Ga的最佳添加量为0.5%.     

热处理工艺对Heusler型Ni2MnGa合金马氏体相变的影响

采用电弧熔炼法熔炼Ni48Mn31Ga21和Ni50Mn255Ga25两种合金,并对这两种合金进行了热处理,借助交流磁化率测定、金相显微镜观察、X射线衍射等手段研究了热处理工艺条件对非化学计量比的Ni48Mn31Ga21合金马氏体相变和结构有序度的影响.结果表明(1)Ni48Mn31Ga21合金相变特征温度为Ms=305K,Mf=297K,As=313K,Af=318K,居里温度Tc=366K;(2)与空冷态相比,淬火态的马氏体转变量降低,经过400℃退火后,随着保温时间t的延长,马氏体转变量上升,当t=50h时达到最大值;(3)Ni48Mn31Ga21合金经过900℃×4d+400℃×50h热处理后,有序度明显提高.     

镀镍液中铁杂质的影响及处理方法

分析了镀镍液中铁杂质的产生途径及其对镀镍层质量的影响。介绍了不同情况下铁杂质的处理方法:ρ(Fe2 )<200mg/L时,可采用添加WZ-Fe除铁剂的方法处理;日常维护,可以采用小电流电解方法除去铁杂质;当Fe2 的质量浓度很高时,用KMnO4或H2O2氧化法进行处理。     

氟钽酸钾结晶工艺研究

氟钽酸钾结晶过程,本身就是一个提纯过程。研究了氟钽酸钾的结晶工艺,主要研究氟钽酸钾的结晶过程中除去杂质钙和碳的方法以及冷却方式改进,从而获得最佳的的氟钽酸钾结晶工艺条件,生产出符合要求的氟钽酸钾产品。     

盐水中杂质离子对离子交换膜性能影响的研究

介绍了盐水中Ca2＋、Ma2＋、SO24-、SiO23-及Fe3＋、Al3＋、Si2＋、Ti2＋、S2-等阴阳离子对离子膜表面的污染情况及这些离子对离子膜性能的影响,并提出了延长离子膜寿命的方法.     

Combustion of Ti+0.5C and Ti+C mixtures of bulk density in inert gas coflow

The combustion of Ti-C mixtures of bulk density under inert gas blowing conditions produced by evacuation of one end of the reaction cell was studied for the first time. The experiments showed that the tested mixtures in quartz cups were not ignited and did not burn without the inert gas (argon) flow. Increasing the rate of gas evacuation from the sample increased the rate of steady-state combustion of the mixture of titanium with carbon black, and for the mixture of titanium with graphite, stabilization of the flat combustion front was observed. It is shown that the presence of small pressure difference (up to 105 Pa) allows control of the combustion process and confirms the basic postulates of the convective-conductive theory of combustion for heterogeneous condensed systems. __________ Translated from Fizika Goreniya i Vzryva, Vol. 45, No. 1, pp. 30–37, January–February, 2009.