无汞碱锰电池专用EMD

以碳酸锰贫矿为原料,采用悬浮电解法改善固相表面性能,使用高效添加剂去除钼、铁等金属杂质,生产无汞碱性锌锰电池专用电解二氧化锰;产品纯度高、视比重大,吸液量更适合碱性锌锰电池的技术要求。制成的电池内电阻小、大电流连续放电性能优越、高压放电容量提高;电池阴极成型好,能满足碱性锌锰电池生产的工艺要求。     

熔盐电渗法制备代汞 Zn-La 合金电极的可行性研究

在ＮａＣｌ－ＡｌＣｌ３熔盐中,于无保护气氛条件下,用熔盐电渗法进行了锌表面渗镧,并用此技术制备了碱锰电池的代汞锌镧合金电极。ＧＩＴＴ曲线的测试结合相图及ＳＥＭ分析证明形成了五种锌镧合金。利用极化电阻的测定来检验锌合金在４０％ＫＯＨ溶液中的抗腐蚀性能,正交实验结果证明了镧是碱锰电池负极的良好代汞添加元素。     

Zn/ZSM-5中Zn的赋存状态对其催化性能的影响

利用原位水热合成法、液相离子交换法、等体积浸渍法、机械混合法以及固相离子交换法制备具有不同赋存状态的Zn/ZSM-5分子筛,并通X射线衍射、透射电镜、27Al魔角旋转核磁共振谱等手段对Zn的赋存状态进行全面表征。结果表明：利用原位水热合成以及液相离子交换法可使Zn物种以Zn2＋形式迁移至分子筛阳离子位;机械混合法以及固相离子交换法可使Zn物种以骨架外ZnO的形式赋存于分子筛表面;等体积浸渍法引入的Zn物种同时以赋存于阳离子位的Zn2+以及分子筛外表面的ZnO颗粒形式存在;Zn物种与分子筛之间的协同作用使得Zn/ZSM-5分子筛在正庚烷催化裂解反应中提高了BTX（苯、甲苯、二甲苯）的收率及选择性。     

超细Si粉对Si/Pb3O4延期药热反应活性和摩擦感度的影响

采用机械球磨法,通过对球磨时间、介质流速等参数的控制,最终得到平均粒度d50=1.75μm的超细Si粉,并进行了粒度和SEM分析.结果表明,随着Si/Pb3O4延期药中超细Si粉含量的增加,其反应放热峰提前,放热量增加,但摩擦感度也相应增加.其中,超细Si粉含量为60%的样品不但具有较高的反应放热量,而且摩擦感度很低.因此,选定60%作为普通Si粉与超细Si粉在级配使用时最为合理的比例.     

Oligocrystalline Shape Memory Alloys

Copper‐based shape memory alloys (SMAs) exhibit excellent shape memory properties in single crystalline form. However, when they are polycrystalline, their shape memory properties are severely compromised by brittle fracture arising from transformation strain incompatibility at grain boundaries and triple junctions. Oligocrystalline shape memory alloys (oSMAs) are microstructurally designed SMA structures in which the total surface area exceeds the total grain boundary area, and triple junctions can even be completely absent. Here it is shown how an oligocrystalline structure provides a means of achieving single crystal‐like SMA properties without being limited by constraints of single crystal processing. Additionally, the formation of oSMAs typically involves the reduction of the size scale of specimens, and sample size effects begin to emerge. Recent findings on a size effect on the martensitic transformation in oSMAs are compared and a new regime of heat transfer associated with the transformation heat evolution in these alloys is discussed. New results on unassisted two‐way shape memory and the effect of loading rate in oSMAs are also reported.     

石英颗粒表面合成六棱柱状Mn~(2+)掺杂Zn_2SiO_4及光致发光性能研究

以SiO2颗粒和Zn(CH3COO)2为原料,采用水热法在不锈钢反应釜中低温制备了Mn2+掺杂的Zn2SiO4荧光材料。利用X线衍射仪(XRD)、扫描电子显微镜(SEM)和荧光分光光度计对影响产物结构及发光性能的反应温度、反应时间、NH4OH质量分数等参数进行研究。结果表明:六棱柱状的ZnSiO4纳米颗粒可以在220℃的低温水热条件下获得,以该法制备的Mn2+掺杂ZnSiO4具有良好的光致发光性能,在220 nm紫外光激发下产生525 nm的绿色发光,并且发光强度随水热反应温度、时间以及NH4OH浓度改变而改变。     

Electrochemical oxidation behavior of Mg–Li–Al–Ce–Zn and Mg–Li–Al–Ce–Zn–Mn in sodium chloride solution

Mg–Li–Al–Ce–Zn and Mg–Li–Al–Ce–Zn–Mn alloys were prepared using a vacuum induction melting method. Their electrochemical oxidation behavior in 0.7 M NaCl solution was investigated by means of potentiodynamic polarization, potentiostatic oxidation, electrochemical impedance technique and scanning electron microscopy examination. Their utilization efficiencies and performances as anode of metal–hydrogen peroxide semi-fuel cell were determined. The Mg–Li–Al–Ce–Zn–Mn exhibited higher discharge activity and utilization efficiency than Mg–Li–Al–Ce–Zn, and gave improved fuel cell performance. The utilization efficiency of Mg–Li–Al–Ce–Zn–Mn is comparable with that of the state-of-the-art magnesium alloy anode AP65. The magnesium–hydrogen peroxide semi-fuel cell with Mg–Li–Al–Ce–Zn–Mn anode presented a maximum power density of 91 mW cm⁻² at room temperature. Scanning electron microscopy and electrochemical impedance studies indicated that the alloying element Mn prevented the formation of dense oxide film on the alloy surface and facilitated peeling off of the oxidation products.     

2,4-二羟基苯甲酸铅铜盐对Al/RDX-CMDB推进剂燃烧性能的影响

为了研究2,4-二羟基苯甲酸铅铜盐（Pb/Cu-SDHB）单独或与其它催化剂复合后对含Al粉和黑索今（RDX）改性双基（Al/RDX-CMDB）推进剂燃烧性能的影响,采用吸收-压延方法制备了推进剂样品,用靶线法测试了推进剂燃速。结果表明：Pb/Cu-SDHB能有效调节推进剂燃烧性能,显著提高了Al/RDX-CMDB推进剂的燃速,并明显降低了压强指数;3.0%Pb/Cu-SDHB与0.65%炭黑复合后使Al/RDX-CMDB推进剂在10~15MPa的压强指数降低至-0.1,10MPa下燃速超过20mm/s。     

Pb/Sn凸剪切性能研究

在实际使用条件下,Pb/Sn凸点会由于承受温度循环而产生剪切应力,剪切应力导致的主要失效方式是开裂.通过对倒装焊后Pb/Sn凸点剪切强度的测量及对剪切后断口的分析,发现破坏主要发生在凸点下金属(UBM)层内部或UBM与Al焊盘之间,平均剪切强度受凸点尺寸影响很小,范围在21～24MPa。     

Effect of Stand-Off Height on Microstructure and Tensile Strength of the Cu/Sn9Zn/Cu Solder Joint

To investigate the effect of stand-off height (SOH) on the microstructure and mechanical behavior of certain solder joints, Cu/Sn9Zn/Cu solder joints with a SOH of 100 μm, 50 μm, 20 μm, and 10 μm were prepared and studied. It was found that, as the SOH is reduced, the Zn content in the solder bulk experiences a rapid decrease due to consumption by metallurgical reaction in the reflow process; hence, the microstructure of the solder bulk is changed significantly from a Sn-Zn eutectic structure to a hypoeutectic structure. By contrast, Cu content in the solder bulk experiences a rapid increase with reducing SOH, and this leads to more dissociative intermetallic compounds (IMCs) in the solder bulk. These compositional and microstructural changes induced by reducing the SOH correlate closely with the mechanical properties of the solder joints. In our study it is found that, as SOH is reduced, the tensile strength of the solder joints decreases, the fracture path of the solder joint transfers from the solder bulk into the interface between the IMC layer and the solder bulk, and the fracture mode tends to change from ductile to brittle. These findings point to a probable way to improve the mechanical properties of miniaturized solder joints by controlling the composition and dissociative IMCs in the solder bulk.