钢表面激光熔覆Ni基ZrO2（4Y）陶瓷层的研究

本文用ＳＥＭ，ＥＤＡＸ，ＸＲＤ和显微硬度计分析了４５钢表面激光熔覆Ｎｉ基ＺｒＯ２（４Ｙ）陶瓷层的组织结构与性能。结果表明：激光熔覆的Ｎｉ基ＺｒＯ２（４Ｙ）陶瓷层出现分层现象，表层为致密的ＺｒＯ２陶瓷层，与钢基体结合的中间层为Ｎｉ基合金；陶瓷层主要由ｔ－ＺｒＯ２相与少量Ｎｉ基γ固溶体组成，激光的快速熔凝过程抑制了ＺｒＯ２的ｔ－ｍ相转变；在最优激光参数条件下，可获得与钢基结合良好的致密ＺｒＯ２陶瓷熔覆     

TiO2对ZrO2—NiCr金属陶瓷烧结特性和相稳定性的影响

本文研究了ＴｉＯ２掺入对ＣａＯ稳定ＺｒＯ２（简称ＣａＳＺ－ＮｉＣｒ）金属陶瓷烧结特性的影响，测定了ＣａＳＺ－ＮｉＣｒ－ＴｉＯ２金属陶瓷烧结样品的密度和显微硬度，结果表明，ＴｉＯ２的掺入能提高ＣａＳＺ－ＮｉＣｒ金属陶瓷的烧结密度和显微硬度，对ＣａＳＺ－ＮｉＣｒ金属陶瓷有助烧结作用。金相观察表明，ＴｉＯ２的掺入改变了ＮｉＣｒ相在金属陶瓷中的形貌，说明了ＮｉＣｒ与ＣａＳＺ的浸润性有一定的改善。ＸＲＤ和Ｅ     

TiO_2对ZrO_2－NiCr金属陶瓷烧结特性和相稳定性的影响

本文研究了ＴｉＯ２掺入对ＣａＯ稳定ＺｒＯ２（简称ＣａＳＺ－ＮｉＣｒ）金属陶瓷烧结特性的影响，测定了ＣａＳＺ－ＮｉＣｒ－ＴｉＯ２金属陶瓷烧结样品的密度和显微硬度，结果表明，ＴｉＯ２的掺入能提高ＣａＳＺ－ＮＩＣｒ金属陶瓷的烧结密度和显微硬度，对ＣａＳＺ－ＮｉＣｒ金属陶瓷有助烧结作用．金相观察表明，ＴｉＯ３的掺入改变了ＮｉＣｒ相在金属陶瓷中的形貌，说明了ＮｉＣｒ与ＣａＳＺ的浸润性有一定的改善．ＸＲＤ和ＥＰＭＡ分析结果显示，ＴｉＯ２偏聚在ＮｉＣｒ金属相中，不影响ＣａＳＺ的稳定性．     

微晶PSZ的显微结构

本文对ＺｒＯ２－ＭｇＯ－Ｙ２Ｏ３－Ａｌ２Ｏ３上元系微晶ＰＳＺ材料的显微结构特征进行了ＴＥＭ分析，认为１１００℃热处理后试样显微结构的变化与ＰＳＺ亚共析分解过程有关；处理后度样中ｔ－ＺｒＯ２析出体的形貌兼具有Ｍｇ－ＰＳＺ中梭形交叉及Ｙ－ＰＳＺ中平行“群集”的显微形貌特生。     

三元系ZrO3固溶体的XPS和XRD研究

对ＣｅＯ２－ＭｇＯ－ＺｒＯ２系固溶体的ＸＰＳ和ＸＲＤ研究结果表明：在１７００℃烧结和随后的１２００℃处理过程中。Ｃｅ＾４＋被还原成Ｃ＾３＋，离子半径的差别使立方相的晶格常数增大，氧的的结合能增大，镁的结合能减小，热处理时，Ｃｅ离子在ＭｇＯ偏析后仍稳定存在于ＺｒＯ２晶格中，使立方ＺｒＯ２发生与会传统Ｍｇ－ＰＳＺ不同的分解反应：ｃ－ＺｒＯ２→ｃ′－ＺｒＯ２＋ｔ－ＺｒＯ２＋ＭｇＯ。     

MSnO_3和MSn_（0．5）Zr_（0．5）O_3（M＝Sr，Ba）的水热合

本文利用水热合成方法对ＭＳｎＯ３和ＭＳｎ（０．５）Ｚｒ（０．５）Ｏ３（Ｍ＝Ｓｒ，Ｂａ）的合成进行了研究，并采用ＸＲＤ、ＳＥＭ和ＩＣＰ等方法对产物进行了表征，结果表明：在Ｍ（ＯＨ）２－ＳｎＯ２（或ＳｎＯ２＋ＺｒＯ２）－ＫＯＨ体系中，当ＫＯＨ／Ｓｎ和ＫＯＨ／（Ｓｎ＋Ｚｒ）≥３０时，２６０℃下晶化５～７天，可获得ＭＳｎＯ３和ＭＳｎ（０．５）Ｚｒ（０．５）Ｏ３纯相，在Ｍ（ＯＨ）２－（ＳｎＯ２＋ＺｒＯ２）－ＫＯＨ－Ｈ２Ｏ体系中，可通过控制介质碱度来获得ＭＳｎＯ３＋ＭＺｒＯ３混合物和ＭＳｎ（０．５）Ｚｒ（０．５）Ｏ３，并根据合成规律初步探讨了反应过程．     

Ni—ZrO2复合镀层的组织结构分析

采用复合电沉积技术制备Ｎｉ－ＺｒＯ２复合镀层，瘩在ＳＥＭ和ＴＥＭ上对其组织结构进行分析。与纯Ｎｉ镀层相比，复合镀层中ＺｒＯ２微粒的存在使基质金属Ｎｉ的晶粒显著细化，孪晶及位错密度均大幅度提高。     

梯度热障涂层热冲击性能研究

采用等离子喷涂的方法,分别获得了２ｍｍ ＺｒＯ２－ＮｉＣｒＡｌ和ＺｒＯ２－Ｎｉ／Ａｌ系梯度热障涂层。热冲击实验结果表明,两种涂层具有不同的失效机理。ＺｒＯ２－ＮｉＣｒＡｌ系的失效是由于基于基体氧化引起的涂层整体脱落;而ＺｒＯ２－Ｎｉ／Ａｌ系的失效是支径向裂纹扩展到Ｎｉ／Ａｌ底层氧化共同作用的结果。     

MSnO3和MSn0.5Zr0.5O3（M=Sr,Ba）的水热合成

本文利用水热合成方法对ＭＳｎＯ３和ＭＳｎ０．５Ｚｒ０．５（Ｍ＝Ｓｒ，Ｂａ）的合成进行了研究，并采用ＸＲＤ、ＳＥ几ＩＣＰ等进行产物进行了表征，结果表明：在Ｍ（ＯＨ）２．ＳｎＯ２（呈ＳｎＯ２＋ＺｒＯ２）－ＫＯＨ体系中，当ＫＯＨ／Ｓｎ和ＫＯＨ（Ｓｎ＋Ｚｒ）≥３０时，２６０℃下晶化５－７天，可获得ＭＳｎＯ３和ＭＳｎ０．５Ｏ３纯相，在Ｍ（ＯＨ）３－（ＳｎＯ２＋ＺｒＯ３）－ＫＯＨ－Ｈ２Ｏ体系中，可通过控制介质     

镍—钨—磷合金镀层在硫酸介质中的耐蚀性

研究了自催化镀Ｎｉ－Ｗ－Ｐ合金镀层在Ｈ２ＳＯ４介质中的耐蚀性，结果表明，在１０％－２０％（ｗｔ）Ｈ２ＳＯ４介质中，Ｎｉ－Ｗ－Ｐ合金镀层有极好的耐蚀性，这是由于一定组成的Ｎｉ－Ｗ－Ｐ合金镀层具有非晶态结构及表面极易形成致密的钝化膜所致。     

基于模具-制件相互作用的复合材料制件固化变形数值模型

针对复合材料制件在成型过程中的固化变形这一关键技术问题,通过在模具与复合材料制件之间引入剪切层的方法,建立了预测复合材料制件固化变形的解析计算模型和有限元仿真模型。剪切层的剪切模量用来衡量固化过程中模具与复合材料制件之间的相互作用,其数值大小通过与实验数据进行比对而得到。基于建立的固化变形模型,与文献中已有的实验结果进行了比较。结果表明:所建立的模型具有较高的可靠性。同时针对L型复合材料制件建立了三维有限元仿真模型,模型中除考虑材料各向异性和化学收缩效应以外,还将成型过程中模具与复合材料制件间的相互作用考虑在内。模拟结果表明:引入模具作用后L型零件的固化变形预测结果更加准确。      

XPS, UPS and ESR studies on the interfacial interaction in Ni-ZrO2 composite plating

The interfacial interaction in Ni-ZrO₂ composite plating prepared by composite electrodeposition has been investigated. The results showed that no new phases were formed at the interfacial regions between matrix Ni and ZrO₂ particles, but the orbital interaction through the mutual overlap of the d orbits does exist in the interfacial regions between Ni atoms and Zr³⁺ ions.     

A simple material model for unidirectionally aligned fibre reinforced composites

A material model for the nonlinear behaviour of composite materials is proposed. The model combines the linear elastic fibre properties with the nonlinear behaviour of the matrix in order to obtain the average properties of the composite. The interaction between the fibre and the matrix is considered using stress partitioning factors, which are based on the experimental behaviour of the material.     

组合梁在负弯矩作用下的刚度分析

为探讨组合梁在负弯矩作用下钢梁与混凝土板之间的滑移效应以及混凝土与纵向钢筋之间的粘结滑移对截面刚度的影响,建立了考虑以上两种滑移效应的组合梁受力模型,并结合试验进行了理论推导和对比分析。结果表明,即便按照完全剪力连接设计的组合梁,滑移效应仍在一定程度上产生了附加曲率,使组合梁的截面刚度比按照换算截面法得到的刚度降低(10%~20%左右),在设计时不可忽略。本文同时推导了计算悬臂组合梁挠度的公式,并为有关连续组合梁刚度的进一步试验研究提供了依据。     

Interface characteristics of carbon nanotube reinforced polymer composites using an advanced pull-out model

An advanced pull-out model is presented to obtain the interface characteristics of carbon nanotube (CNT) in polymer composite. Since, a part of the CNT/matrix interface near the crack tip is considered to be debonded, there must present adhesive van der Waals (vdW) interaction which is generally presented in the form of Lennard-Jones potential. A separate analytical model is also proposed to account normal cohesive stress caused by the vdW interaction along the debonded CNT/polymer interface. Analytical solutions for axial and interfacial shear stress components are derived in closed form. The analytical result shows that contribution of vdW interaction is very significant and also enhances stress transfer potential of CNT in polymer composite. Parametric studies are also conducted to obtain the influence of key composite factors on bonded and debonded interface. The result reveals that the parameter dependency of interfacial stress transfer is significantly higher in the perfectly bonded interface than that of the debonded interface.     

复合材料固化相关黏弹性性能演化及残余应力分析

通过对复合材料固化度和温度相关黏弹性本构方程的分析,定义一个能综合反映固化度和温度等对复合材料黏弹性性能影响的无量纲参数De_m。当参数De_m都大于10~2时,复合材料基体处于流动状态;当参数De_m都小于10~(-2)时,复合材料为弹性状态;仅当部分参数De_m小于10~2而大于10~(-2)时,复合材料处于黏弹性状态。以AS4纤维/3501-6树脂复合材料为例,基于对其参数De_m在典型固化工艺过程中的演化,研究该复合材料黏弹性性能的发展过程,发现基于参数De_m分析得到的凝胶点时间与实验结果一致。根据复合材料黏弹性性能对残余应力发展的影响,将复合材料残余应力计算分为流动阶段和黏弹性阶段,并建立了相应的状态相关黏弹性本构模型。最后通过与原始模型预测结果的比较验证了提出的本构模型,表明本文提出的计算方法与原始黏弹性本构模型计算结果一致,但大大降低了计算所需的时间和存储空间。     

Measurement method for dispersion states of filler particles in particulate composite materials by macroscopic permittivity

A new model for estimating macroscopic permittivity was proposed to predict filler particles' dispersion states in a particulate composite material. In the model, the estimation targets are randomly packed composite materials. The composite materials were represented as a cluster of unit cells. A proposed layer structure model connected the unit cells. The macroscopic permittivity was estimated by calculating the synthetic capacity of the cluster. The proposed model was validated by comparisons between estimated and measured macroscopic permittivity of several particulate composite materials. It was also identified that the proposed model could estimate the permittivity more accurately than an existing theoretical equation's one due to considering the effects for the dispersion states of filler particles. Furthermore, it was indicated that the proposed model could also estimate the dispersion states of filler particles by the measured permittivity. The applicability of the method was confirmed by comparisons between estimated and experimental dispersion states of filler particles.     

超声无皂乳液原位合成Pd-P(MMA-AMPS)复合微球及其表征

将超声波作用于含有2-丙烯酰氨基-2-甲基丙磺酸(AMPS)和甲基丙烯酸甲酯(MMA)的氯化钯水溶液中,在不加任何引发剂、乳化剂和还原剂的条件下,合成带有酰胺基、磺酸基等官能基团的Pd-P(MMA -AMPS)复合微球。考察了单体质量配比对复合微球形貌的影响,用XRD、TGA、FTIR、TEM和粒度分析仪等技术对样品进行表征,并探讨了合成反应机制。结果表明,超声辐射可实现Pd2+的还原与单体聚合的同步进行,并且金属钯与基体P(MMA - AMPS)共聚物之间存在一定的相互作用。优化条件下制得的复合微球,钯质量分数为20%左右,粒径约0.76μm,还原得到的钯粒子均匀分散于聚合物微球内。     

Inhomogeneous States in Strongly Correlated Electron Systems with Orbital Degrees of Freedom

We study a strongly correlated electron system with charge carriers characterized by different values of orbital quantum number. It is shown that such a system exhibits a tendency to phase separation owing to a competition between the charge localization in the orbitally ordered state and metallicity. The effect of orbital ordering on the phase separation is studied employing a minimal model including itinerant charge carriers at the orbitally ordered background. It is shown that at low doping, the phase separation may appear in systems with orbital degeneracy even without taking into account the magnetic structure. We considered this effect using two versions of the model. In the first one, we assumed that in the absence of doping, the orbital structure results from the interaction of core electrons with the lattice. Electrons appearing due to doping move in this background. In an alternative model, the same electrons take part in the formation of both band structure and orbital ordering.      

长玻纤增强复合材料注塑成型构件强度分析

基于广义牛顿流体本构方程,采用ARD-RSC纤维取向模型,考虑纤维间相互作用,仿真预测长玻纤增强复合材料注塑构件的纤维取向分布;应用复合材料细观力学Eshelby夹杂理论和Mean Field均匀化方法,建立长玻纤增强复合材料均质化RVE模型;综合运用复合材料细观建模、离散RVE模型场、注塑成型和结构有限元分析技术,提出了长玻纤增强复合材料注塑构件强度分析方法。对推力杆注塑构件进行强度分析,显示仿真危险位置与实际破坏位置较为吻合。在此基础上对推力杆进行结构改进,结果表明杆体中间部分在拉伸载荷下的最大主应力降低了57.18%,在压缩载荷下的最大主应力降低了71.25%。