添加元素对Ag-Sn系合金粉末氧化性能的影响研究

采用预合金粉末内氧化法探索了金属元素(Sb,La,In)对Ag-sn系合金粉末的氧化行为,进而研究不同内氧化工艺下,含不同添加剂(Sb2O3, 3,La2O3, In2O3)C对Ag-Sn系电接触材料氧化性能的影响.结果表明,添加La的Ag-sn合金粉末的氧化物弥散均匀分布在银基体上,添加Sb的Ag-Sn合金粉末的氧化物主要聚集在粉末的颗粒边界上.     

Bi掺杂AgSnO2（12）电接触材料的制备及性能研究

将采用化学沉淀法制备的Bi掺杂量为25%(原子分数)的SnO2纳米颗粒(Sn0.75Bi0.25O2)作为增强相,借助于粉末冶金法制备了AgSnO2(12)电接触材料,分析了Bi元素掺杂对电接触材料性能的影响。试验结果表明,Sn0.75Bi0.25O2纳米颗粒增强的AgSnO2(12)电接触材料组织结构均匀,密度、硬度高,导电性好。电性能试验表明,Sn0.75Bi0.25O2纳米颗粒增强材料的燃弧时间短、能量低,接触电阻低且稳定,抗电弧侵蚀能力强。     

添加物Bi对AgSnO_2触头材料的影响

AgSnO2是最有可能替代AgCdO的新型材料,在其制备方法中,合金内氧化法是主要方法之一。但在制备过程中合金粉末氧化速度较慢且不能完全内氧化,添加金属元素促进合金内氧化是一个重要研究方向。本文将Bi与Ag、Sn粉经机械合金化得到AgSnBi合金粉末,将合金粉末压制成型、烧结、致密化加工后置于电阻炉中在大气气氛中进行粉末内氧化。采用内氧化物增重法分析Bi对AgSn合金内氧化性能的影响。利用PhilipsXL30W/TMP型扫描电镜观察试样AgSnO2-Bi2O3的显微组织及形貌,并用其能谱仪进行微区成分分析。研究结果表明Bi元素大大地提高了AgSn合金的内氧化速度,并且氧化得到的AgSnO2-Bi2O3材料组织致密。     

Fe掺杂纳米复合Ag-SnO2电接触材料耐电压性能

利用化学共沉淀和常压烧结等方法制备出纳米复合Ag-SnO2和Fe掺杂Ag-SnO2触头合金,对合金触头进行了耐电压实验和SEM形貌观察.实验结果发现制备的触头合金呈现纳米第二相弥散均匀分布在Ag基体中.纳米复合电接触材料耐电压强度分布比商业用AgSnO2In2O3集中,但平均耐电压强度比商用低9.8%～29.7%.放电后,纳米复合电接触材料表面蚀坑凸凹起伏程度小,烧蚀轻微.     

添加Bi对AgSnO2触头材料的影响

AgSnO2是最有可能替代AgCdO的新型材料,在其制备方法中,合金内氧化法是主要方法之一.但在制备过程中合金粉末氧化速度较慢且不能完全内氧化,添加金属元素促进合金内氧化是一个重要研究方向.本文将Bi与Ag、Sn粉经机械合金化得到AgSnBi合金粉末,将合金粉末压制成型、烧结、致密化加工后置于电阻炉中在大气气氛中进行粉...     

电触头材料专利选登

专利申请号 :0 0 80 0 663公开号 :1 3 0 2 3 3 9专利名称 :汽车继电器用电触点材料及使用该材料的汽车继电器　　本发明的目的是提供用于汽车用空调电磁离合器电感性负载的具备极好耐久性的汽车继电器用电触点材料 ,并提供以往所没有的高耐久性汽车继电器。本发明的汽车继电器用电触点材料是以成分为 5.0～ 1 0 .0 wt% Sn、2 .0～ 5.0 wt% In、余 Ag组成的 Ag-Sn-In合金经内氧化而获得的 Ag-Sn O2 -In2 O3 合金 ,或由成分为 5.0～ 1 0 .0 wt% Sn、2 .0～ 5.0 wt% In、0 .0 1～ 0 .50 wt% Ni、余 Ag组成的 Ag-Sn-In-Ni合金经内氧化…     

内氧化法制备银氧化锡电接触材料

AgSnO2电接触材料具有优良的抗电弧侵蚀性和抗熔焊性,在交直流接触器、功率继电器和低压断路器等领域已经部分或全部取代了AgCdO材料。内氧化法是制造AgSnO2电接触材料工艺最成熟、应用最广泛的一种方法。本文计算了Ag-Sn合金的内氧化热力学条件参数,论述了内氧化过程中SnO2颗粒的形核、长大和粗化过程,并采用合金粉末成形-内氧化-热挤压新工艺制备了SnO2颗粒细小弥散、性能优越的AgSnO2电接触材料。     

用于低压功率开关的烧结AgSnO2电触头材料的制造方法

(一 )　　 Ag Me O触头材料已被广泛地应用于低压功率开关 (例如电流接触器或自动电路断路器 )中 ,其中用得最多的是 Ag Cd O材料。由于众所周知的 Cd有毒等原因 ,目前人们正大力研究开发 Ag Sn O2 和 Ag Zn O用以替代 Ag Cd O,但一般的 Ag Sn O2 和 Ag Zn O并不能完全达到 Ag Cd O所具有的高性能 ,例如用 Ag Sn O2 替代 Ag Cd O时 ,由于 Sn O2 具有较高的热稳定性 ,在电弧的作用下触头表面形成牢固氧化层 ,使得其接触电阻和温升高于 Ag Cd O。但是从节银的角度来说 ,因为Ag Sn O2 比 Ag Cd O电弧烧损小 ,电寿命高 ,所以 …     

不同添加剂对AgSn合金粉末氧化过程的影响

采用雾化法分别制备了Ag-9.7Sn、Ag-9.65Sn-0.5In和Ag-9.65Sn-0.5Bi合金粉末,使用热重分析仪研究了相关合金800℃氧化动力学曲线,并分析了合金粉末氧化前后的粉末颗粒形貌及表面成分。结果表明:Bi的添加促进Ag Sn合金粉末的氧化,其氧化机制只经历指数增重型快速氧化阶段就趋于完全氧化;Ag-9.65Sn-0.5In合金粉末的氧化机制与Ag-9.7Sn合金粉末类似,其快速氧化增重过程分为两阶段,且第一阶段快速增重速率比第二阶段快;微量添加In能促进第一阶段快速氧化增重,In与Sn氧化后形成一层均匀致密的氧化膜阻碍了第二阶段快速氧化增重。     

AgCd和AgSn合金粉的相结构分析

采用X射线衍射及峰形拟合技术,结合AgCd和AgSn合金相图对雾化工艺制备的AgCd和AgSn合金粉的相结构进行分析,结果表明,AgCd雾化合金粉中Cd原子进入Ag的晶格格点位置,形成固溶结构,在氧化后可以使Ag与CdO之间有比较牢固的化学键结合;AgSn雾化合金粉中含有Ag3Sn和Sn两相,析出的Sn相与Ag相晶体结构差异较大,氧化后Ag与SnO2之间的结合不牢固,这可能是导致AgCdO电接触材料比AgSnO2电接触材料性能优越的一个重要原因。     

氢氧等离子体合成过氧化氢过程的能效研究

为提高氢氧等离子体合成H2O2技术的能量效率,通过分析放电过程的反应器能效及电源能量注入效率,确定了影响合成总能效的主要因素。考察了反应器电极间距、电源放电频率及注入功率对反应器能效和电源能量注入效率的影响。发现减小电极间距、提高放电频率和注入功率有利于提高反应器能效,但不利于提高电源能量注入效率。本研究中可以得到150 gH2O2/kWh的反应器能效,但由于较低的电源能量注入效率,致使合成H2O2的总能效不超过9 gH2O2/kWh。因此,提高等离子体法合成H2O2过程的总能效,不仅需要设计高能效的等离子体反应器,还需为反应器负载开发适配的电源,而后者是提升该技术能量效率的关键。     

Electron-Ion Transport in ZrO2-Y2O3-CeO2 Ceramics

Simultaneous conduction of oxide ions and electrons in solid ceramic systems provides the capability for oxygen transport under a concentration gradient without the need for an externally applied electric field. In the present study, ionic transference numbers have been measured in the ZrO₂-5.8%Y₂O₃-10%CeO₂ system by open circuit Emf measurements involving different metal/metal oxide electrodes. In order to correlate the ionic transference number with grain size, high-density ceramic discs of different grain sizes (50 nm–5 m) were prepared by sintering pressed powders at various temperatures and times. Hydrothermal synthesis was used to prepare nanocrystalline powders of the above material with uniform crystallite size (10 nm) and chemistry. Emf measurements on the samples suggested both ionic and electronic transport, the ionic transference number decreasing with increase in the grain size. This observation was attributed to an increase in the amount of continuous crystalline grain boundary phase in the ceramics as the grain size increased. The presence of crystalline silicate and zirconate phases in the grain boundary region was confirmed by electron microscopic imaging combined with microanalysis. In the large grain (5 m) ceramics, the ionic transference number decreased linearly with temperature. As the grain size decreased, a maximum occurred in the ionic transference number vs. temperature curve. This maximum became more pronounced at smaller grain sizes. Better grain-grain contact and the doping effect of trivalent Ce in the grain boundary core are proposed to explain this observation.     

RuO_2-IrO_2-TiO_2析氧催化剂的制备工艺

以Ti N、RuCl3和H2IrCl6为原料,用真空浸渍-热分解法制备了RuO2-IrO2-Ti O2,研究了煅烧温度和n(Ru+Ir)∶n(Ti)对产物的影响。XRD分析表明:Ti N在高温煅烧时氧化生成金红石型Ti O2,RuO2、IrO2和Ti O2以固溶体的形式存在。CV、阳极极化曲线和EIS测试表明:RuO2-IrO2-Ti O2的最佳煅烧温度为400℃,随着n(Ru+Ir)∶n(Ti)的提高,催化剂的活性增强;在相同电位下,RuO2-IrO2-Ti O2的电流密度大于IrO2,可用作固体聚合物电解质(SPE)水电解催化剂。     

富氧火焰原子吸收光谱法测定铅钙锡合金中的锡

采用富氧火焰 (Air—C2 H2 —O2 )原子吸收光谱法直接测定铅钙锡合金中 0 1%以上的锡。对仪器工作条件、测定体系酸度、共存离子干扰等作了研究。方法准确度高 ,结果重现性好     

Thermoelectricity of p-Fe2O3-SO3-SiO2-others and n-Fe2O3-SiO2-CuO-others

Thermoelectric minerals have been found at Loei Province, in the northeastern part of Thailand. Local mineral specimens were prepared in the powders and bulk solids form by crushing, calcination and annealing, pressure and sintering, cutting and polishing. Mineral samples were used to analyze the composition and phase, determine the thermoelectric property and efficiency, design and construct a thermoelectric generator. Chemical composition and phase identification of powder samples were analyzed by the x-ray fluorescence (XRF) and x-ray diffraction (XRD), respectively. XRF and XRD results indicated that the mineral samples comprised the SO₃-CaO-SiO₂-others, Fe₂O₃-SO₃-SiO₂-others, Fe₂O₃-SiO₂-others and Fe₂O₃-SiO₂-CuO-others. From the thermoelectric property and efficiency determinations, the p-SO₃-CaO-SiO₂-others, p-Fe₂O₃-SO₃-SiO₂-others, n-Fe₂O₃-SiO₂-others and n-Fe₂O₃-SiO₂-CuO-others bulks were found to exhibit the thermoelectric figure of merit in orders of 10^?14, 10^?11, 10^?14 and 10^?13 K^?1, respectively. A fabricated thermoelectric generator made from ten pairs of p-Fe₂O₃-SO₃-SiO₂-others and n-Fe₂O₃-SiO₂-CuO-others legs that can be provided the open circuit voltage and short circuit current up to 48.30 mV and 0.14 μA for a temperature difference of 39.80 K at room temperature, respectively. While the internal resistance decreased and reached a value of 665 kΩ.     

Mixed Hydroxide Precursors for La2Ti2O7 and Nd2Ti2O7 by Homogeneous Precipitation

Feasibility of formation of stoichiometric precursors of either M₂ (TiO)₂(C₂O₄)₅ 4H₂O (M = La and Nd) or coprecipitated hydroxides of M(OH)₃+TiO(OH)₂ was investigated by two solution routes at different pH values. Composition of precipitates obtained at pH = 7.0 by coprecipitation method starting from La or Nd nitrates and potassium titanyl oxalate corresponded to a physical mixture of La or Nd(C₂O₄)₃ 9.5H₂O and TiO(OH)₂7·H₂O which on thermal decomposition did not yield phase pure M₂Ti₂O₇. However, precipitation from La or Nd nitrates and titanium tertrachloride by urea hydrolysis yielded homogeneous mixture of hydroxides of La or Nd and Ti, which on pyrolysis at 950°C yielded phase pure La₂Ti₂O₇ and Nd₂Ti₂O₇. Use of potassium titanyl oxalate as precursor for Ti, led to selective precipitation of La or Nd oxalate even at pH as low as 0.1 leading to sequential precipitation of La or Nd oxalate followed by Ti hydroxide at pH = 3.0. The resultant precipitate on pyrolysis underwent typical solid-state reaction.     

pH-MnO_2电极电位与MnO_2活性

本文对用于电池的MnO_2进行电化学评价,测定不同产地锰矿的pH—电极电位关系,每个样品的模拟制作,锌—锰干电池并测定共放电容量,通过比较放电容量和MnO_2的电极电位,从而对MnO_2进行活性评价。     

过氧化氢钝化工艺的改进

传统的过氧化氢钝化工艺较难掌握，钝化条件比较苛刻，钝化效果一般，还容易出现一种褐色不明附着物。经过大量试验研究，对过氧化氢钝化工艺进行了改进，钝化效果明显提高。     

Dielectric and Piezoelectric Properties of Nonstoichiometric SrBi2Ta2O9 and SrBi2Nb2O9 Ceramics

Nonstoichiometric SrBi₂Ta₂O₉ (SBT) and SrBi₂Nb₂O₉ (SBN) ceramics were prepared by a solid state reaction method. X-ray diffraction analysis showed that single-phase of Bi-layered perovskite was obtained. With different Sr/Bi content ratios of SBT and SBN, Curie temperature (T_C), electromechanical factor (K_p) and mechanical quality factor (Q_m) were measured. T_C of SBN (SBT) rose from 414C (314C) to 494C (426C) when Sr/Bi content ratio was increased from 0.55/2.3 to 1.2/1.8. In the most Sr-deficient/Bi-excess ratio of 0.55/2.3, the maximum values of Q_m were obtained approximately 1013 and 3325 for SBT and SBN, respectively.