Ni／Ni1Al—TiC系梯度功能材料的组成结构设计与制备

选择Ｎｉ／Ｎｉ３Ａｌ－ＴｉＣ体系的ＦＧＭ，对其在制备过程的残余热应力进行了计算机用限元模拟，在综合考虑热应力最小，热应力发生位置以及纯ＴｉＣ侧应力状态等因素的基础上，完成了ＦＧＭ的组成结构设计与优化，得到了组成分布指数Ｐ＝１．６的最佳设计结果，按此设计结果，采用热压烧结工艺，制行出完整的，无宏观缺陷的Ｎｉ／Ｎｉ３Ａｌ－ＴｉＣ系ＦＧＭ样品。     

Ni/Ni_3Al-TiC系梯度功能材料的组成结构设计与制备

选择Ｎｉ／Ｎｉ３ＡｌＴｉＣ体系的ＦＧＭ，对其在制备过程中的残余热应力进行了计算机有限元模拟。在综合考虑热应力最小、热应力发生位置以及纯ＴｉＣ侧应力状态等因素的基础上，完成了ＦＧＭ的组成结构设计与优化，得到了组成分布指数Ｐ＝１．６的最佳设计结果。按此设计结果，采用热压烧结工艺，制备出完整的、无宏观缺陷的Ｎｉ／Ｎｉ３ＡｌＴｉＣ系ＦＧＭ样品。     

TiC／Ni3Al系梯度功能材料在稳定状态下的隔热应力及其组成分布优化

通过实验方法，测定了ＴｉＣ／Ｎｉ３Ａｌ复合材料的诸物性参数，在此基础上，对于ＴｉＣ／Ｎｉ３Ａｌ系梯度材料（ＦＧＭ）在稳定状态下产生的隔热应力，利用有限元方法进行了热弹性模型下的三维解析，在考虑热应力最小，比应力最小以及ＴｉＣ侧应力状态等因素之后，对圆反状ＴｉＣ／Ｎｉ３Ａｌ系梯度材料的组成分布进行了优化。     

MgO／Ni系梯度功能材料的设计与制备

对ＭｇＯ／Ｎｉ系梯度功能材料（ＦＧＭ），分别用实验和微观力学模型测定和计算了用于热应力缓和设计的各物性参数。讨论了两种结果之间存在差异的原因。用有限元方法模拟了制备过程中ＦＧＭ的热应力，得到ＭｇＯ／Ｎｉ系ＦＧＭ的综合设计准则。按设计结果进一步调整粉末工艺性质，成功地烧制出ＭｇＯ／Ｎｉ系ＦＧＭ。     

1Cr18Ni9Ti材料在多次冷拉延中的热处理

0　引　言随着现代化学工业的迅速发展 ,越来越多的1Ｃｒ1 8Ｎｉ9Ｔｉ材料的拉延件在化学工业中应用也日益广泛。而 1Ｃｒ1 8Ｎｉ9Ｔｉ材料在冷拉延过程中对冷作硬化是非常的敏感 ,一次拉延后对以后的再次拉延也就带来了很大的困难 ,这就提出了1Ｃｒ1 8Ｎｉ9Ｔｉ材料在多次拉延过程中采用什么的热处理的问题。1　拉延过程分析从拉延的过程分析 ,拉延中材料受到拉应力和压应力 ,使材料的晶格产生滑移 ,从而发生大量的错位造成晶格的变形 ,使材料的内应力增大。加之 1Ｃｒ1 8Ｎｉ9Ｔｉ材料由于晶格变形在内应力和变形应力的作用下它会部分的由…     

自蔓延高温合成技术制备TiC／Ni3Al复合材料的研究

采用ＳＨＳ工艺，从Ｔｉ，Ｃ，Ｎｉ，Ａｌ四种元素态粉末原料对ＴｉＣ／Ｎｉ３Ａｌ复合材料进行了探索研究，测定了燃烧温度变化曲线，结果表明，燃烧反应温度较高，温度变化复杂，且与ＴｉＣ的含量有关，对不同相组成的产品进行了ＸＲＤ及ＳＥＭ分析，表明在这四种元素态粉末存在的系统中，经过ＳＨＳ过程，设计的ＴｉＣ和Ｎｉ３Ａｌ相是稳定存在的两个相，合成产品呈多孔洞，疏松的开装状，ＴｉＣ晶粒细小且呈圆球状。     

PSZ－Mo系梯度功能材料的热应力缓和设计与制备

对ＰＳＺ－Ｍｏ系梯度功能材料（ｆｕｎｃｔｉｏｎａｌｌｙｇｒａｄｉｅｎｔｍａｔｅｒｉａｌｓ简称ＦＧＭ）在制备过程中的热应力缓和性能进行了优化设计，用有限元方法解析了ＰＳＺ－Ｍｏ系两层叠层材料（即非梯度功能材料）在制备过程中的热应力分布情况。同时解析了ＰＳＺ－Ｍｏ系ＦＧＭ在制备过程中的热应力分布及缓和规律。揭示了ＰＳＺ－Ｍｏ系ＦＧＭ在制备过程中的热应力大小与组成分布形状指数Ｐ的关系，对所研究的体系通过热应力解析，得到制备中热应力缓和最佳时的Ｐ值，同时，对ＦＧＭ的制备工艺进行了研究，用粉末法分别制备出２４ｍｍ×５．６ｍｍ和３０ｍｍ×５ｍｍ完整的ＦＧＭ试样。     

PSZ—Mo系梯度功能材料的热应力缓和设计与制备

对ＰＳＺ－Ｍｏ系梯度功能材料在制备过程中的热应力缓和性能进行了优化设计，用有限元方法解析了ＰＳＺ－Ｍｏ系两层叠层材料（即非梯度功能材料）在制备过程中的热应力分布情况。同时解析了ＰＳＺ－Ｍｏ系ＦＧＭ在制备过程中的热应力分布及缓和规律。揭示了ＰＳＺ－Ｍｏ系ＦＧＭ在制备过程中的热应力大小与组成分布形状指数Ｐ的关系，对所研究的体系通过热应力缓和最佳时的Ｐ值，同时，对ＦＧＭ的制备工艺进行了研究，用粉末法分别     

Inconel 600合金与1Cr18Ni9Ti钢的焊接

通过对Ｉｎｃｏｎｅｌ６００合金与１Ｃｒ１８Ｎｉ９Ｔｉ钢的焊接性分析，采用ＷＥＬ ＡＣ１８２焊条确定了合理的焊接工艺，成功地组焊了Ｉｎｃｏｎｅｌ６００合金与１Ｃｒ１８Ｎｉ９Ｔｉ不锈钢异种材料法兰。     

（Ng,Ti）C—Ni金属陶瓷中包裹结构的形成机理及其化学键研究

利用ＳＥＭ，ＥＰＭＡ，ＴＥＭ／ＥＤＡＸ等测手段对（Ｎｂ，Ｔｉ）Ｃ－Ｎｉ金属陶瓷中的包裹结构形成机理作了研究。结果表明：它是由于该金属陶瓷在烧结时，细小的（Ｎｂ，Ｔｉ）Ｃ颗粒溶解在熔融态的Ｎｉ中，当Ｔｉ，Ｎｂ及Ｃ的浓度达到大颗粒的饱和浓度时，在大颗粒表面沉淀，继面Ｎｉ同其扩散而形成的，用离散变分－Ｘａ方法计算表明：包裹层的金属键程度要比包裹结构中心的高。     

Effect of Ni foam on the microstructure and properties of AlN ceramic/Cu brazed joint

Aluminum nitride (AlN) ceramics and oxygen-free Cu were brazed with multilayer filler consisted of Ag-Cu-Ti +Ni foam. The microstructure and forming principle of AlN/Cu joints were studied and the influence of Ni foam on the joints was focused. The result shows that the composition of AlN/Cu joint was AlN/TiN/Ni₃Ti+Cu(s,s)+CuTi+Ni foam+Ag(s,s)/Cu. The joint strength was only 66.7 ± 3.7MPa with pure Ag-Cu-Ti solder and the fracture occurred inside AlN ceramics due to the residual stress. The foam nickel reacted with Ag-Cu-Ti filler metal to form Ni₃Ti during brazing process. Ni foam still retained the basic skeleton structure during brazing, and the mechanical capacity of AlN/Cu joint was enhanced significantly. The maximum shear strength of the brazed joint can reach 89.6 ± 4.5 MPa with .1 mm Ni foam, and the fracture position changed to the brazing filler. The result shows that nickel foam can reduce the residual thermal stress, and the mechanical properties of AlN/Cu joints were improved.     

Phase transformations as a result of thermal annealing of nanocomposite Fe–Ni / Fe–Ni–O particles

The paper presents the results of a study of changes in structural and magnetic characteristics, as well as phase transformations in Fe–Ni/Fe–Ni–O nanoparticles obtained by chemical synthesis and subsequent thermal annealing. It was found that the initial nanoparticles are a three-phase system consisting of Fe–Ni–O oxide with a spinel structure and a Fe–Ni alloy with a face- and body-centered cubic lattices. As a result of thermal annealing, a decrease in the Fe–Ni phase was established with subsequent ordering of the Fe–Ni–O phase with a decrease in the crystal lattice parameter and an increase in the degree of crystallinity. During resurces tests, it was found that for single-phase Fe–Ni–O nanoparticles, the lifetime is close to 500 discharge/charge cycles, which is a good indicator of the working life and makes it promising to use Fe–Ni/Fe–Ni–O nanoparticles as anode materials for lithium-ion batteries.     

Interfacial behavior on Al2O3/HAYNES® 214™ joints fabricated by solid state bonding technique with Ni or Cu–Ni–Cu interlayers

The residual stresses due to the difference in thermal expansion between ceramic and metal is a significant parameter to control during the fabrication of ceramics/metal joint. In this work, residual stress distribution, after solid state bonding of different joints, was measured using X-ray diffraction (XRD) and Vickers Indentation Fracture (VIF) methods. Tensile stress concentration in alumina caused by the thermal expansion mismatch in the Al₂O₃/Ni/Ni alloy (HAYNES^® 214?) joint severely deteriorated the assembly and caused cracks in alumina. To solve this problem, this paper shows that the use of a Cu/Ni/Cu multi-layer, associated with the direct copper bonding method (DCB), by pre-oxidation of copper, reduces significantly the tensile residual stresses in alumina material. Consequently, this process offers the possibility of producing an interlayer with a high melting temperature and hence joints which can withstand high-temperatures.     

Reactive brazing of silicon nitride to Invar alloy using Ni foam and AgCuTi intermediate layers

Silicon nitride (Si₃N₄) ceramic and Invar alloy have been brazed by using AgCuTi active filler and the Ni foam was added to further improve mechanical properties of joints in this study. The microstructure of Si₃N₄/Invar brazed joint changed obviously after adding Ni foam with different thickness. Ni foam reacted with the AgCuTi active filler during brazing, but it did not completely disappear and still maintained the basic frame structure after brazing. The average shear strength of the brazed joints with 0.2 mm Ni foam could reach 180 MPa, and their thermal cycle lifetime also improved significantly. The addition of Ni foam shifted the fracture location of joints from Si₃N₄ ceramic to brazing seam. These results indicated that the Ni foam could act as a buffer layer to reduce the residual thermal stress, and improve the mechanical properties of Si₃N₄/Invar joint.     

Thermal explosion in mechanoactivated 3Ni + Al mixtures

Explored was thermal explosion in mechanoactivated 3Ni + Al mixtures. Mechanoactivation was found to result in an abnormal decrease in the effective activation energy E and ignition temperature T_ign for thermal explosion. Analysis of reaction thermogram allowed us to find out the kinetic function. Mechanoactivation conditions for synthesis of Ni₃Al in thermal explosion mode have been optimized. SHS reaction in 3Ni + Al mixtures mechanoactivated for 180 s was found to obey the first-order kinetics.      

Novel hierarchical Ni/MgO catalyst for highly efficient CO methanation in a fluidized bed reactor

A facile synthesis of the hierarchical Ni/MgO catalyst is reported, with extremely fine dispersion of Ni nanoparticles (NPs) and high surface oxygen mobility. The hierarchical Ni/MgO catalyst exhibits higher activity for CH₄ formation than that prepared by the impregnation method. The enhanced activity and thermal stability of the hierarchical Ni/MgO catalyst is attributed to hierarchical MgO particles with a multilayer structure and high surface oxygen mobility. This induces better metal‐support interactions, high Ni dispersion to prevent Ni NPs sintering, and the high surface oxygen mobility provides a high resistance to carbon deposition. Compared to the impregnated Ni/MgO catalyst, the hierarchical Ni/MgO catalyst exhibits a better fluidization quality and a higher attrition‐resistance in a fluidized‐bed reactor. This approach to improve the catalytic activity by creation of hierarchical Ni/MgO particles is encouraging for the design of novel catalysts for synthetic natural gas production, especially from the perspective of matching catalysts with fluidized‐bed reactors. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2141–2152, 2017     

Preparation and thermal conductivity of novolac/Ni/graphite nanosheet composites

A high thermal conductivity novolac/nickel/graphite nanosheet (novolac/Ni/NanoG) composite was synthesized through in situ polymerization. Graphite nanosheet (NanoG) was prepared by sonicating expanded graphite (EG) in an aqueous alcohol solution and was plated with nickel through an electrodeposition method. The X‐ray diffraction spectrum shows that nickel was successfully plated onto the graphite surface and the nickel thickness is about 27.89 nm. The microstructures of the Ni/NanoG were characterized by scanning electron microscopy and transmission electron microscopy. The results reveal that nickel particles with the average diameter of 25 nm are coated on NanoG surface homogeneously and densely. Energy dispersive spectrometry spectrum confirms that the Ni content coated on NanoG surface, whose atomic percentage is 61%, is much higher than that of C element. The values predicted by theoretical model were underestimated the thermal conductivity of novolac/Ni/NanoG composites. Among NG, EG, NanoG, and Ni/NanoG four kinds of particles, the Ni/NanoG improved the thermal conductivity of novolac resin significantly. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012