用Kroner模型计算取向薄膜的弹性矩阵与X射线弹性常数

首先用Kroner模型计算了具有丝织构的TiN薄膜的弹性矩阵,当材料具有较强的丝织构时,材料弹性矩阵的对称关系将发生变化,得到的弹性矩阵与各向同性同种材料的弹性矩阵相差很大,相同分量的值一般相差在13-20GPa之间,然后计算了TiN薄膜的弹性常数曲线随φ角的分布,当应力测试方向不同时,即使是同一晶面,弹性常数也会产生差异,而且弹性常数随φ角的分布在低φ角区发生了弯曲,计算了TiN薄膜X射线弹性常数曲线的弯曲情况与实测的PVDTiN薄膜应力测试曲线相似。     

TiN多弧离子镀涂层质量与X射线衍射图谱

对ＴｉＮ多弧离子镀涂层的质量和性能进行了试验与分析。试验结果表明：涂层的质量和性能与Ｘ射线衍射图谱之间存在着对应关系,在Ｘ射线衍射图谱中具有强烈ＴｉＮ（１１１）择优取向的涂层表面光亮、结合强度高、硬度高、面磨性好。     

X-ray elastic constant determination and residual stress of two phase TiAl-based intermetallic alloy

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｉＡｌｉｎｔｅｒｍｅｔａｌｌｉｃｃｏｍｐｏｕｎｄｈａｓｌｏｗｅｒｄｅｎｓｉｔｙ ,ｈｉｇｈｅｒｔｅｍｐｅｒａｔｕｒｅｓｔｒｅｎｇｔｈ ,ｈｉｇｈｅｒｓｔｉｆｆｎｅｓｓａｎｄｂｅｔ ｔｅｒｏｘｉｄａｔｉｏｎｒｅｓｉｓｔａｎｃｅｃｏｍｐａｒｅｄｔｏｔｈｅｃｏｎｖｅｎｔｉｏｎａｌｈｉｇｈ ｔｅｍｐｅｒａｔｕｒｅａｌｌｏｙｓ[1 ] ,ｔｈｅｒｅｆｏｒｅ,ｉｔｉｓｅｘｐｅｃｔｅｄｔｏｂｅａｐｏｔｅｎｔｉａｌｌｉｇｈｔｍａｓｓｈｅａｔ ｒｅｓｉｓｔａｎｔｍａｔｅｒｉａｌ.Ｅｘｔｅｎｓｉｖｅｓ…     

GH4169晶面衍射弹性常数计算与测量

根据复相材料细观力学模型,预测了镍基高温合金等效弹性响应,基于宏观应力-应变关系,理论计算了GH4169及组分材料等效弹性性质参数,即等效弹性模量■,等效体积模量■,等效剪切模量■和泊松比■,与文献报道的实验值进行对比分析。结果显示:GH4169合金理论计算值■=218.60 GPa,■=180.20 GPa,■=84.20 GPa,■=0.298与实验值偏差分别为7.16%、10.69%、6.58%、0.67%;γ′相理论计算值■=201.10 GPa,■=173.70 GPa,■=76.93 GPa,■=0.307与实验值偏差分别为1.42%、0.40%、2.00%、1.66%,较小的误差证明了该模型的准确性;进一步,理论预测了镍基高温合金细观弹性响应,基于单轴载荷作用下细观弹性应力-应变关系,理论计算了GH4169合金γ-(Ni-Cr-Fe)相(220)晶面衍射弹性常数,即E_(220)=233.89 GPa,v_(220)=0.284;同时,采用四点弯曲标定载荷应力,结合X射线衍射应变实验测量了γ-(Ni-Cr-Fe)相(220)晶面衍射弹性常数,并与理论计算值对比分析。结果表明,实验测量值E_(220)=248.00 GPa、v_(220)=0.276与理论值的偏差分别约为5.69%、2.90%,证实了该理论模型的准确性,也为衍射法测量残余应力研究提供理论基础。     

Corrosion Resistance of PAPVD TiN Coating on AISI 304 Stainless Steel

In this work the corrosion resistance of PAPVD TiN hard coatings on AISI 304 stainless steel with a titanium interlayer has been addressed. Cyclic voltammetry corrosion tests in NaCl 3.5% solutions were performed for samples prepared by depositing TiN/Ti onto steel using different deposition parameters. The surface morphology of the samples was examined by using a scanning electron microscope (SEM) and phase analysis was performed by X-ray diffraction (XRD). The cyclic voltammetry curves showed two distinct behaviours. Firstly, a reduction in corrosion resistance was observed when current density was increased for the whole potential range studied. The second observation, no less important, was the increase in corrosion resistance compared to the uncoated steel. The TiN films deposited showing (III) preferred orientation showed better corrosion resistance than films presenting other orientations.     

Crystal Structure and X-ray Powder Diffraction Data for Rare Earth Compound PrNiSn

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｅｒｎａｒｙｉｎｔｅｒｍｅｔａｌｉｃｃｏｍｐｏｕｎｄｓｃｏｎｔａｉｎｉｎｇｒａｒｅｅａｒｔｈｍｅｔａｌｓｈａｖｅｖａｒｉｏｕｓｃｒｙｓｔａｌｓｔｒｕｃｔｕｒｅｓａｎｄｍａｎｉｆｅｓｔｓｅｖｅｒａｌｉｎｔｅｒｅｓｔｉｎ...     

X射线衍射法测定加载条件下镍基单晶高温合金的表层应力状态

利用X射线四轴衍射仪测定了四点弯曲弹性加载条件下镍基单晶高温合金表层的宏观应变与应力,并与应变片及机械拉伸测定的数据进行了比较.分析了采用不同弹性常数及不同分峰方式处理得到的应力数据的差异.结果表明,实验数据重复性较好,实验误差为±30 MPa;XRD测量得出的应力应变结果与室温拉伸以及应变片测量结果符合较好;室温下合金基体相(γ)的弹性常数大于沉淀强化相(γ'),且基体相(γ)承受的应力大于沉淀强化相(γ').     

Elastic properties of polycrystalline gold thin films: Simulation and X-ray diffraction experiments

The elastic behavior of supported gold thin films has been studied using a framework in which the elastic interaction between grains and the actual structure of the film (i.e. preferential grain orientation and grain shape) are taken into account. Experiments were carried out using synchrotron X-ray diffraction combined with in-situ tensile testing and thereafter, no assumptions on the residual stress state and on the stress-free lattice parameter a₀ have to be made. Modeling of grain elastic interactions is based on the extension of Eshelby-Kröner model, which allows for estimating the elastic behavior of polycrystals considering the texture and the shape of the crystallites. Flat-disc shaped grains arrangement is shown to yield the best representation of the elastic behavior of the fiber-textured gold thin films composed of columnar grains. This non-intuitive representation results from free-surface effect.     

Oxidation of titanium nitride in oxygen: Behavior of TiN0.83 and TiN0.79 plates

The oxidation of 0.13 mm thick TiN_0.83 plates between 850 and 1005°C and 0.38 mm thick TiN_0.79 plates between 890 and 1220°C was studied at oxygen pressures in the range 15–600 Torr. The oxidation behavior of the first compound, TiN_0.83, was found to be very close to that recently described for the nitride TiN_0.91. There was formation of a rutile scale with a layered structure and the kinetics were quasilinear for conversion degrees 0.25<<0.9. By applying a pseudolinear oxidation model involving a diffusion regime through a scale of variable thickness, it was found that the activation energy of the limiting process, i.e., the diffusion of the reactants through the inner growing layer, was 43 kcal/mole. The second compound, TiN_0.79, showed a slightly better oxidation resistance. The irregular kinetic curves obtained (mainly above 1000°C) were associated with sintering and grain growth in the oxide starting at the outer surface of the scale and gave indirect information on the pressure dependence of the linear oxidation of nitrides TiN_0.83 and TiN_0.91.     

Oxidation behavior of monolithic TiN and TiN dispersed in ceramic matrices

The mechanism and kinetics of high-temperature (up to 1500°C) oxidation of pressureless-sintered TiN and hot-pressed silicon nitride-TiN, alumina-TiN, aluminum nitride-TiN, and AlON-TiN ceramic composites were studied in air under isothermal and nonisothermal conditions. Analysis of the oxidation products revealed the formation of rutile in the temperature range from 600 to 1000°C. An interaction of TiO₂ with the matrix and/or its oxidation products was observed at higher temperatures. The oxidation of TiN-containing composites shows different behavior depending on the temperature. The presence of fine isolated inclusions of TiN (<30 mass %) in the silicon-nitride matrix does not change the mass gain during oxidation or increases it only slightly, as compared with a TiN-free material. For materials containing a continuous skeleton of TiN (>30 mass %) a noticeable increase of the oxidation rate was observed.Presented at the 6th Session of the Joint Committee on Corrosion of Ceramics of the German Materials Research Society and German Ceramic Society, Karlsruhe, April 9, 1992.     

Coefficients of thermal expansion of thin metal films investigated by non-ambient X-ray diffraction stress analysis

Cu, Ni and Pd layers were deposited by DC-magnetron sputtering on Si wafer substrates. The mechanical stresses and the coefficients of linear thermal expansion (CTEs) were investigated by non-ambient (in-situ) X-ray diffraction measurements employing the sin²ψ crystallite group method. It was found that, in the as-produced state, the CTEs were larger than expected on the basis of literature values for the Cu and Ni layers, but not for the Pd layer. Upon annealing of the layers grain growth and decrease of the crystalline imperfection, monitored by in-situ X-ray diffraction measurements of the diffraction line broadening, occurred. The increase of the crystallite size was paralleled by a decrease of the CTE values for the Cu and Ni films. The grain-size dependence of the CTE is discussed in terms of the coordination (state of bonding) of atoms at grain boundaries and surfaces.     

X-ray microbeam quantification of grain subdivision accompanying large deformations of copper

This work reports the application of X-ray microbeam diffraction to quantifying grain subdivision processes in copper. Polychromatic synchrotron X-radiation was used to study samples in the as-received (low deformation) and 100% torsion strained material. The large range of domain disorientations (within individual grains) observed in the highly strained material agrees with results on other f.c.c. materials obtained by electron beam methods; it is not surprising, therefore, that models of texture development which do not include this effect predict too rapid sharpening of preferred orientation compared to experimental pole figures.     

Elastic constants of Al and TiN calculated by ab initio method

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氮气氛下电火花沉积TiN层的形成机理及微观特征

以工业纯钛TA2为电极,用N2作为反应及保护气体,采用电火花沉积方法,在45钢基体表面制备出了含TiN的硬质沉积层.采用金相显微镜、扫描电镜和X射线衍射等分析检测方法,对沉积层形成机理、微观结构及界面行为进行研究,并测试了沉积层的显微硬度分布.结果表明,电火花氮化沉积层与基体形成良好的冶金结合,沉积层主要由TiN相组成,组织致密、均匀、较连续,厚度为30～40 μm,显微硬度最高达1 515 HV,是基体硬度的5倍以上,可以有效地改善基体的表面性能.     

低弹性模量钛合金用于钛烤瓷的力学分析

钛与烤瓷结合强度的不足制约了临床上钛瓷修复体的应用,本研究尝试引入低弹性模量钛合金烤瓷的概念,并用力学计算方法对金瓷界面承受剪切、中部弯曲载荷等破坏条件予以模拟和分析论证.结果表明,低弹性模量钛合金在承受剪切作用力时界面应力水平低于纯钛6%以上,在承受中部弯曲载荷条件下低弹性模量钛合金需要增加金属基底厚度(>2 mm)才能获得较好的刚度和应力分布,在临床条件下可以满足这一厚度要求.     

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 从应用角度介绍了取向分布函数（ODF）分析的原始数据采集方法、分析原理和图谱解释方法。在ODF分析中需要粉末标样,有许多因素影响ODF分析结果,这些因素包括接收狭缝宽度、管压和管流的大小、光路中的单色器和限高光栏是否使用。     

氮电弧制备陶瓷表面层中TiN相形态及生长机制

利用氮电弧熔化纯钛基体表面,原位制备氮化钛（TiN）陶瓷表面层,研究陶瓷表面层的形成机理、TiN相的生长形态及其生长机制．结果表明,氮电弧熔化过程为非平衡快速冷却凝固过程,冷却速度可达10^2～10^3 K／s,表面层中TiN相的微观生长方式具有多样性．在熔池中过冷度较小的位置,TiN晶体为螺型位错侧面长大方式,而熔池...     

Tribology of nitriding layer, TiN coatings and their complex on AISI D2 steel

The sliding wear and impact wear resistances of D2 steel with nitriding layer, PVD titanium nitride coating and their duplex treatment were investigated. The experimental results suggest that the duplex treatment has the best sliding and impact wear resistances under experimental conditions. And the wear resistance of PVD titanium nitride is better than that of nitriding. The impact wear resistance and wear mechanism of all three surface layers remain unchanged under impact load of 0.2 J or 1 J. All samples end with the same symptom of flaking.     

低弹性模量Ti-27Nb-8Zr医用钛合金组织与力学性能

利用光学显微镜、扫描电镜和X射线衍射仪研究Ti-27Nb-8Zr(质量分数, %)医用钛合金固溶后在不同时效温度下组织的变化规律,重点讨论不同显微组织对合金弹性模量和强度的影响。结果表明,固溶处理后,合金组织由β+α”两相构成,具有相对低的弹性模量和强度;时效后,组织中包含β、α、ω三相,弹性模量和强度显著升高,随着时效温度的升高,组织长大,弹性模量和强度降低