用Ti/Ni/Ti多层中间层进行Si_3N_4陶瓷的部分瞬间液相连接

在１３２３Ｋ和０．１ＭＰａ压应力下用Ｔｉ／Ｎｉ／Ｔｉ多层中间层进行Ｓｉ３Ｎ４陶瓷的部分瞬间液相连接．测定了不同连接时间的接头四点弯曲强度,对连接界面进行了ＳＥＭ,ＥＤＸ和ＸＲＤ分析．结果表明：Ｔｉ和Ｎｉ相互扩散形成的液态合金与Ｓｉ３Ｎ４反应并浸润;液相区等温凝固后,形成Ｓｉ３Ｎ４／反应层／ＮｉＴｉ／Ｎｉ３Ｔｉ／Ｎｉ的过渡层连接;连接时间为７．２ｋｓ时,ＮｉＴｉ层已基本消失．分析了陶瓷部分瞬间液相（ＰＴＬＰ）连接的特征,提出了陶瓷ＰＴＬＰ连接参数优化的模型．     

复合电镀（Ni—P）—SiC的新工艺

研究了复合电镀（Ｎｉ－Ｐ）－ＳｉＣ过程，发现随镀液中ＳｉＣ浓度增加，阴极极化随之增加，分散能力下降，镀液中加入混合稀土后，镀层硬度由５７４ＨＶ提高到６０２ＨＶ，相对磨损量由４．５４×１０＾－２ｇ／ｃｍ＾２下降到３．５×１０＾－２ｇ／ｃｍ＾２与Ａ３钢相对耐磨性提高４．１倍。     

干摩擦及润滑条件下Si3N4／45号钢摩擦副的摩擦学性能

在销－盘试验机上对Ｓｉ３Ｎ４／钢摩擦副的摩擦磨损性能进行了研究。选用的速度及载荷变化范围分别为０．８￣３．２ｍ／ｓ和５８．８￣２３５．２Ｎ。在干摩擦和水润滑条件下，摩擦系数和陶瓷磨损率随速度、载荷均有不同程度的增大，但用油润滑时，较高速度下，Ｓｉ３Ｎ４磨损率略有减小。较低速度下（〈１．６ｍ／ｓ）水对Ｓｉ３Ｎ４／钢摩擦副的摩擦性能无明显改善，速度大于１．６ｍ／ｓ时，水使Ｓｉ３Ｎ４／钢摩擦副摩擦系数降     

用Ti／Ni／Ti多层中间进行Si3N4陶瓷的部分瞬间液相连接

在１３２３Ｋ和０．１ＭＰａ压应力下用Ｔｉ／Ｎｉ／Ｔｉ多层中间层进行Ｓｉ３Ｎ４陶瓷的部分瞬间液相连接。     

TiN（Ni）对GPS Si3N4复合材料导电性能的影响

本文研究了ＴｉＮ（Ｎｉ）对ＧＰＳＳｉ３Ｎ４复合材料导电性能的影响，实验结果表明，添加ＴｉＮ粒子可显著降低Ｓｉ３Ｎ４复合材料的电阻率，Ｎｉ的加入对降低Ｓｉ３Ｎ４复合材料的电经有一定的作用，选择电阻率小于１Ω．ｃｍ的试样进行电火花加工，加工性能良好。     

氮化硅超细粉原位生长“无缺陷”a—氮化硅晶须

研究了用加压氮化法（ｉｎｃｒｅａｓｉｎｇ ｐｒｅｓｓｕｒｅ ｎｉｔｒｉｄａｔｉｏｎ，简称ＩＰＮ法）制备高活性、高纯度的氮化硅超细粉。用这种超细粉在一定温度范围内原位生长出“无缺陷”的ａ－Ｓｉ３Ｎ４晶须，其截面直径×长的尺寸分别为（０．１￣０．３ｕｍ）×（１０￣３０ｕｍ）。在氮化硅基体中加入“无缺陷”ａ－ＳｉＮ４晶须后，材料的断裂韧性ＫＩｃ达１０．５±０．９ＭＰａ·ｍ＾１／２；室温强度ａｆＲＴ达９２     

α相和β相氮化硅的形成机理与动力

使用气流磨粉碎的硅粉（Ｓｉ）（Ｓｉ９９．３％，ｄｐ＝５．１μｍ，Ｓｇ＝３．２ｍ＾２／ｇ）和氮气（Ｎ２）（纯度９９．９９９８％）为反应物，在１３００～１３６７℃下反应形成β－Ｓｉ３Ｎ４，其反应机理与动力学参数被研究。反应产物由ＸＲＤ进行定量分析，相形成的机理和它们的形态用扫描电镜（ＳＥＭ）确定，我们发现α相和β相的形成机理不同，β－Ｓｉ３Ｎ４在１３００℃的实验数据适合于界面化学反应控制的动力学模型，     

陶瓷/陶瓷(金属)部分瞬间液相连接

根据Ｓｉ３Ｎ４／Ｔｉ／Ｎｉ／Ｔｉ／Ｓｉ３Ｎ４和Ａｌ２Ｏ３／Ｔｉ／Ｃｕ部分瞬间相连接的实验结果,提出了描述部分瞬间液相连接过程和选择连接参数的模型以制备高强耐热接头,并对模型的应用进行了阐述,选择最佳连接参数的方法;（１）确定最佳反应层厚度;（２）选择靠近陶瓷中间层厚度;（３）决定连接时间。     

复合电镀（Ni－P）－SiC的新工艺

研究了复合电镀（Ｎｉ－Ｐ）－ＳｉＣ过程，发现随镀液中ＳｉＣ浓度增加，阴极极化随之增加，分散能力下降。镀液中加入混合稀土后，镀层硬度由５７４ＨＶ提高到６０２ＨＶ，相对磨损量由４．５４×１０－２ｇ／ｃｍ２下降到３．５×１０２ｇ／ｃｍ２，与Ａ３钢相比耐磨性提高４．１倍。     

N+注入Ti/Si3N4的摩擦行为研究

研究了Ｓｉ３Ｎ４陶瓷材料及镀膜Ｔｉ／Ｓｉ３Ｎ４材料当Ｎ＾＋注入前后的摩擦学行为,考察了样品表面划痕轨迹的ＳＥＭ形貌,结合Ｘ射线衍射,对离子注入改性机理和摩擦学性能刊物了探讨,在Ｔｉ和Ｓｉ３Ｎ４界面上离子的混合及形成Ｔｉ２Ｎ相使Ｔｉ膜的附着力增加。     

碳纳米管化学镀Ni/Ni3P的表面改性研究

采用化学镀方法制备了Ni包覆碳纳米管(CNTs),利用红外光谱(IR)、场发射扫描电镜(FESEM)、能谱分析(EDS)以及X射线衍射分析(XRD)研究了混酸纯化、敏化活化、化学镀Ni工艺以及镀后热处理(HT)对化学镀的影响.结果表明:混酸纯化后CNTs在其表面形成了大量的羧基(-COOH)和羟基(-OH)等官能团,提高了CNTs在镀液中的分散性;当稳定剂NH4Cl为35 g/L时,随着镀液温度的升高,镀层Ni含量先升高后降低;当温度为85℃时,镀Ni效果最佳,镀层Ni的质量分数为69.05％;热处理后镀层由非晶态的Ni-P层转变为Ni3P晶态结构,镀层更加平滑致密.     

负载Ni催化剂表面Ni的形态及其甲烷化活性研究

采用浸渍法制备了具有不同Ni负载量的NiO/γ-Al2O3催化剂,经过不同温度下的焙烧处理后得到一系列共9个催化剂样品。借助X射线光电子能谱分析比较Ni负载量和焙烧处理温度对Ni在催化剂载体表面存在的形态。结果表明,对于Ni负载量为10%的样品,Ni离子会在催化剂表面以八面体配位的镍和表面尖晶石NiAl2O4的形态存在,随着焙烧温度的提高,以表面尖晶石NiAl2O4形式存在的Ni的比例也增加;当Ni负载量达到20%以上,以NiO形态存在的Ni会更多的出现在催化剂表面,而提高焙烧温度不利于NiO的存在。CO甲烷化微反评价的结果显示,表面富集NiO的催化剂具有更好的甲烷化催化活性。     

Ni/graphene/Ni nanostructures for spintronic applications

Here, we demonstrate chemical synthesis of graphene based nano-spin valve like structures using nickel layers as ferromagnetic contacts grown on both sides of graphene sheets. Magnetic measurements indicate that the spins on two opposite nickel layers are coupled through antiferromagnetic interaction up to room temperature. However, they switch into parallel configuration when a magnetic field of about 2000 Oe is applied resulting in a change in magnetoresistance of ~19%.     

Partial oxidation of methane to syngas over Ni/MgO, Ni/CaO and Ni/CeO2

Partial oxidation of methane to syngas at atmospheric pressure and 750°C was examined over Ni/MgO, Ni/CaO and Ni/CeO₂ catalysts with nickel loading of 13 wt%. All catalysts had similar high conversion of methane and high selectivity to syngas, which nearly approached the values predicted by thermodynamic equilibrium. However, only Ni/MgO showed high resistance to carbon deposition under thermodynamically severe conditions (CH₄/O₂ = 2.5, a higher CH₄ to O₂ ratio than the stoichiometric ratio). Its catalytic activity remained stable during 100 h of reaction, with no detectable carbon deposition. The oxidation of carbon deposited from pure CH₄ decomposition and from pure CO disproportionation was investigated by in situ TPO-MS study which showed that both were effectively inhibited over Ni/MgO. In addition, the catalysts were characterized by TPR, XRD and XPS. It was revealed that the excellent performance of Ni/MgO resulted from the formation of an ideal solid solution between NiO and MgO. This revised version was published online in August 2006 with corrections to the Cover Date.     

化学镀Ni—P及Ni—P—PTFE镀层的性能研究

从硬度、耐磨性、摩擦及耐蚀性等几个方面研究了镀层的性能。同时研究了镀层成份及镀液中稳定剂对镀层耐蚀性的影响,交通过电化学手段和Ｘ－光电子能谱ＸＰＳ地镀层进行了研究。     

Ni-Ti合金中Ni表观活化能的测定

对活化能的理论机理进行了推导,在氧化性溶液中进行了Ni-Ti合金浸泡试验,通过ICP分析出溶液中浸出Ni的溶解量,根据阿伦尼乌斯方程拟合曲线得出Ni-Ti合金中Ni的活化能为E= 37.48 kJ/mol。结果表明,Ni的溶解由表面化学反应及原子扩散混合控制。     

雷尼镍催化剂

雷尼镍（Ｒａｎｅｙ－Ｎｉ）是一种历史悠久、应用广泛的催化剂，近几十年来，在Ｒａｎｅｙ－Ｎｉ制备、表征和改性等方面的研究进展，大大加深了对其物性和制备机理的了解。本文对此作了综述。     

Ni／Ni3Al—TiC系梯度功能材料的热应力缓和特性设计

本文选择Ｎｉ／ＮｉＡｌ－ＴｉＣ体系的ＦＧＭ，对其在制备过程中的残余絷应力进行了计算机有限元模拟。在综合考虑热应力最小，应力强度比值最小以及纯ＴｉＣ侧应力状态等因素的基础上，完成了ＦＧＭ体系的热应力缓和特性设计，得到组成分布指数Ｐ＝１．６的最佳设计结果。     

电刷镀镍及镍磷非晶态合金镀层性能研究

利用扫描电镜、能谱分析仪、ＭＭ－２００型试验机及ＭｉｃｒｏｍｅｔⅡ数显式显微硬度计对镀层的硬度、摩擦磨损性能及耐蚀性能进行了分析测试,并研究了热处理对其组织结构及性能的影响,从而分析比较了各种镀层性能及差异,在此基础上为确定进口汽车缸套修复的最佳镀层提供了依据。     

Effect of magnetic charging of Ni on electrolytic codeposition of Zn with Ni particles

Composite materials with unique properties can be produced by codepositing an inert phase during a cathodic metal deposition process. The feasibility of codeposition is mainly determined by the interaction of the inert phase and the cathodically deposited metal. When both the inert phase and the cathode or the cathodically deposited metal are ferromagnetic substances, codeposition can be promoted by magnetizing the inert phase prior to codeposition. Codeposition of Zn with Ni particles on a steel cathode from a weakly acidic zinc chloride based bath was investigated. The increased interaction between the magnetically remanent Ni particles and the steel cathode resulted in substantially higher percentages of Ni included in the deposit layer, especially at low concentrations of Ni particles in the bath. The model of Guglielmi, modified for conducting particles, proved to be valid; the value of adsorption parameter k _ad changed with magnetic remanency. Cathodic Zn deposition efficiency decreased with increasing concentration of Ni particles in solution and increasing Ni content in the deposit. The principle outlined can also be applied to systems with nonferromagnetic inert phases by coating these with ferromagnetic substances.List of symbols AG constant (Guglielmi) (V^–1) - BG constant (Guglielmi) (V^–1) - B magnetic field flux density (T) - Br remanent magnetic field flux density (T) - c _p concentration particles in bath (kg m^–3) - d _d deposit layer thickness (m) - F Faraday's constant (C mol^–1) - H magnetic field strength (A m^–1) - i current density (A m^–2) - i ₀ exchange current density (A m^–2) - k _ad Langmuir adsorption constant - M magnetization (A m^–1) - Mr remanent magnetization (A m^–1) - n valence of deposited metal - V _p volume of particles deposited per area of electrode surface (m) - W molecular weight (kg mol^–1) - X _p weight percentage of Ni in deposit - Y _p volume percentage particles in bath Greek symbols _p volume fraction of Ni in deposit - overpotential (V) - _c cathodic efficiency - ₀ magnetic permeability of vacuum (Vs A^–1 m^–1) - _{p, 0} constant for particle deposition (m s^–1) - _m density of metal matrix (kg m^–3) - degree of strong adsorption coverage degree of loose adsorption coverage - degree of loose adsorption coverage