机械加工和表面粗糙度对金属材料硬度测试数据的影响

讨论了机械加工和表面粗糙度等多种因素对金属材料面氏硬度测试数据的影响。由于机械加工过程中的机械－热作用，合得切口处的硬度最低，随着与切口距离的增大，HB值逐渐增加。超出该影响区后，HB值趋于稳定。这是一现象还随机械加工的方法、条件,以及表面粗糙度和材料原始硬度等的不同，而有不同的变化规律。     

浅谈农机零配件表面粗糙度的测量

阐述了表面粗糙度对零件使用性能的影响及评定表面粗糙度的基本原则，叙述了零件表面粗糙度的几种测量方法，以及使用针描法测量零件表面粗糙度应注意的问题。     

粗糙度模式对硬盘气膜承载特性的影响

当前硬盘中磁头磁盘之间气膜的厚度已经接近或低于分子平均自由程,在这种情况下表面粗糙度及气体稀薄效应的影响不容忽视.应用最小二乘有限差分法,求解考虑气体稀薄效应并引入压力流因子和剪切流因子的量纲一雷诺方程,研究了不同粗糙度模式下硬盘超低飞高(1nm~2nm)气膜的承载特性.数值结果表明:粗糙度模式对超低飞高气膜压力分布及承载力的影响较大,而对压力中心的影响较小;在各种粗糙度模式情形下,磁头取横向粗糙度模式时,可使气膜压力分布升高,并提高气膜的承载力.     

温度对聚氯乙烯缺口冲击强度及断面粗糙度的影响

研究了温度对聚氯乙烯 PVC 缺口冲击强度、断口形貌特征及断面粗糙度的影响。结果表明,PVC 缺口冲击强度和断面粗糙度参数 R_s 随温度变化,在脆化温度 T_h 处存在极小值,前者取决于真实断裂表面积大小;后者受控于局部高强变形及裂纹分叉扩展综合作用。低温冲击断面上易观察到裂纹分叉扩展形成的弧形条纹及分层。     

利用大气中放电来测量表面特性的新方法

研制了一种新型的探测器，利用气体放电和外部电路猝灭的方法测定样品表面发射的低能光电子。它能在大气或各种气氛中工作。可用于测定表面功函数、膜厚、表面污染及材料缺陷。有较大实用价值。     

THE ASSESSMENT OF SURFACE FATIGUE EFFECTS IN TOUGHENED ZIRCONIA USING A NEW POINT CONTACT METHOD

The effects of repeated point contact loading of a toughened ceria-stabilised zirconia ceramic, CeTZP, by softer metallic cones, have been investigated. All tests were conducted on a purpose-designed and built computer-controlled apparatus. The results clearly indicate that zirconia is susceptible to cyclic loading. The evolution of the cyclic deformation and cracking processes have been analysed in terms of contact pressures, applied loading conditions and number of cycles. The ground tips of both quenched, and quenched and tempered, silver steel cones are plastically deformed during the initial loading cycle to produce a conforming planar surface approximately 50-100 μm in diameter. In all cases, plastic deformation in the CeTZP was observed within, and adjacent to, the contact zones. The degree of plastic deformation increased as the number of cycles increased. The expansion associated with the tetragonal-to-martensitic phase transformation in the zirconia caused granular lifting from the surface, at the edge of the contact zone. This resulted in localised spalling at the peripheries of the contact zones, where the tensile stresses are the highest, followed by a radial expansion at higher cycle numbers. This investigation has identified that the rate of evolution of the fatigue damage, in decreasing order of significance, was controlled by: (a) cone hardness, (b) cyclic load amplitude and (c) mean load.     

SURFACE ROUGHNESS OF SPUTTERED SILICON. I. SURFACE MODELING

A mathematical model for the calculation of surface roughness was developed for focused ion beam (FIB) sputtering. The surface roughness function is a combination of the beam function and the material function. The beam function includes ion type, ion acceleration energy, and beam parameters. Furthermore, the beam parameter incorporates ion flux, the ion beam intensity distribution profile, tailing and neighboring of the successive beams, dwell time, etc. The intensity distribution inside the ion beam is considered to be Gaussian. The cumulative intensity over the total milling area is calculated by the algebraic summation of individual beam intensity delivered to every pixel successively. The material function includes the inherent material properties related to the ion beam micromachining. If one knows the beam function and material function, surface roughness at the bottom of the sputtered features can be calculated using this model.     

SURFACE ROUGHNESS OF SPUTTERED SILICON. II. MODEL VERIFICATION

Experimental verification of the mathematical surface roughness model for sputtered silicon was performed. The beam shape and its significant level of intensity were determined first by measuring the topography of craters sputtered by focused ion beam (FIB). Then the beam function was generated for various combinations of beam parameters. The material function was developed both by theoretical and experimental analysis. These two functions were then used in the model to calculate the theoretical surface roughness. Microsurface analysis was formed by FIB sputtering of a (100) silicon wafer. The surface roughness at the bottom of the sputtered features was then measured using an atomic force microscope. The theoretical surface roughness was found to be within ±1 and ±5 nm of the measured surface roughness with the measurement uncertainty (standard deviation) of about ±0.36 and ±0.85 nm for R_a and R_t, respectively.     

钻环法测量水泥路面表面残余应力的初步研究

水泥混凝土在强度形成过程中,温度、湿度变化以及水化反应等因素将引起水泥砂浆体积变化,当体积变化受到约束时,水泥混凝土内将产生残余应力,导致水泥混凝土内部出现微裂缝。国内外进行了大量收缩变形等因素引起的水泥混凝土内部应力变化的研究,但尚需要验证。该文将从"反"方向对水泥混凝土内的残余应力进行研究,即如何测量得到水泥混凝土表面的残余应力。根据金属工程中应用较为广泛的钻孔法测量表面残余应力技术,考虑水泥混凝土主要由水泥石和石料组成,尺寸差别较大,提出利用钻环法对水泥混凝土表面残余应力进行测量的可行性。2007年美国联邦航空管理局(FAA)的机场道面实验室,进行了钻环法测量水泥混凝土表面残余应力的初步试验,该文将建立有限元模型,对存在初始应力的板进行钻环模拟,通过与封闭解的对比,验证有限元模型的准确性,通过与FAA的试验结果进行对比分析,验证了钻环法测量水泥混凝土表面残余应力的可行性。     

测量断口分维的周长-最大直径方法

本文提出了测量断口分维的周长—最大直径方法,并与周长—面积方法进行了对比。当测量码尺很小时,两种方法所测分维比较接近,当测量码尺增加时,周长—面积方法所测分维有下降趋势,而周长—最大直径方法所测分维比较稳定。     

一种测量超微粒子表面氧化层厚度的新方法

通过XPS分析与Ar~ 刻蚀相结合的方法，测量了Fe_(50)Pd_(50)合金超微粒子（UFP）的表面氧化层厚度，发现它的表面氧化层为1．4um厚，小于电镜观察到的表面非晶层厚度，表明此方法测量的表面氧化层厚度不受表面吸附层的影响，并且能直接了解UFP表面的具体氧化状态。     

扫描探针显微镜在粗糙度、纳米尺寸、表面形貌观测方面的应用

扫描探针显微镜是近十几年来在表面特征、表面形貌观测方面最重大的进展之一，是纳米测量学的基本工具。叙述了扫描探针显微镜的工作原理、检测模式及在观察检测纳米级的粗糙度、微小尺寸、表面形貌方面的特点和方法，比较了原子力显微镜、常规的表面轮廓仪、干涉显微镜、扫描电子显微镜在表面特性、表面形貌观测方面的性能，着重介绍了扫描探针显微镜在粗糙度、纳米尺寸、表面形貌观测方面的应用和存在的问题。     

THREE-DIMENSIONAL CRACK-SHAPE EFFECTS DURING THE GROWTH OF SMALL SURFACE FATIGUE CRACKS IN A TITANIUM-BASE ALLOY

Abstract— A basic study was performed on the evolution of three-dimensional shapes of small surface fatigue cracks during fatigue, and the effect of this evolution on small-crack growth behavior of a titanium-base alloy. Specifically, the nature and the magnitude of variations in crack aspect ratio, a/c (a is the crack depth and c is the half-surface crack length), during cyclic crack growth and its impact on growth rates have been studied. Experiments were performed on naturally initiated micro-cracks in a microstructure consisting of equiaxed primary-α₂ phase in a Widmanstätten (transformed β) matrix. Several cracks under stress ratio (R) levels of 0.1 and ?1, were studied. A specialized experimental system, consisting of a laser interferometer (to measure precisely the small-crack surface displacements), and a photo microscope (to automatically and continuously photograph the fatigue micro-cracks) was employed in the study. Apparent aspect ratios of surface cracks were calculated from the compliance response and the surface crack length data as a function of fatigue cycles. These data enabled accurate calculations of growth rates at the surface crack tip as well as the tip at depth in the bulk over the entire crack growth period, thus giving an insight into the crack growth process. Measurements of closure levels of small cracks were also performed and were used to partly account for the differences in growth rates. In the comparisons of small-crack growth data with the large-crack data, surface growth rates correlated relatively well with the large-crack data. Growth rates at depth exhibited large variations due to the irregularity of crack fronts at this location, and these rates deviated significantly from the large-crack behavior. Additionally, these growth rates varied between different cracks. An attempt was made to rationalize these observations in terms of the effects of inhomogeneities present in the microstructure.     

双热流法测定低温真空下固体界面的接触热阻

本文介绍了低温真空下固体界面间的接触热阻机理,重点介绍一种采用双热流计法既能精确测量圆柱型又能测量薄片型试样间接触热阻的装置,该装置还能同时测量材料的热导率。同时,文中给出一些材料在低温真空下的接触热阻值。     

地表粗糙度对山区峡谷地形桥址区风场影响研究

为研究地表粗糙度对山区峡谷地形桥址区风环境的影响,通过计算流体力学数值模拟的方法,对不同粗糙度下理想峡谷与真实峡谷模型中主梁跨中位置的风剖面进行了研究。通过理想模型的计算分析,确定了不同风向角下主梁跨中风剖面随粗糙度变化的一般规律,结合对峡谷内流场特点的分析,揭示了粗糙度对峡谷内风速造成影响的原因,并在真实地形模型中进行了验证,根据地表种类细化了粗糙度设置方案。研究表明,在峡谷地形条件下,粗糙度对风速的影响与常规地形有明显差异,在主梁高度处,随着粗糙度的增加,主梁跨中风速可能会有不同程度的增加。研究结论为山区峡谷地形处桥梁设计风速确定提供了依据。     

短纤维增强聚丙烯中纤维取向分布的测定

报导了一种用于测定短玻璃纤维增强聚丙烯复合材料中纤维取向的快速、简便、准确的新方法，该方法采用氢氟酸刻蚀玻璃纤维提高相差，使得复合材料样品截面上的纤维取向可以直接在相差光学显微镜下观测。采用该方法测定了注射成型的复合材料中纤维的取向分布，实验结果与计算机模拟的结果基本一致。     

基于小样本记录的柱面网壳结构地震响应评估

结构的地震反应可以采用时程分析法或反应谱法来估计,在用时程分析法计算结构抗震设计需求时,中国抗震设计规范规定了选择3条或至少7条地震动记录的准则。可以用峰值加速度（PGA）或加速度反应谱（SA）来对地震动记录进行调幅,但用哪一个地震动强度参数来调幅为最佳还是未知的。该文针对柱面网壳的分析结果表明：合适的地震动强度参数取决于所需的结构反应,为降低由地震动记录间差异引起的结构最大杆件内力、支座反力或基底剪力的变异性,采用PGA调幅地震动记录要优于SA,而对于结构的最大位移反应则恰好相反。由于结构频谱十分密集以及受高阶振动模态的影响,采用反应谱法计算结构最大杆件内力或基底剪力是不合适的。同时,该文计算了采用3条和7条地震动记录准则获得的结构最大杆件内力和基底剪力的统计值,以期能为选择合适的地震动强度参数和地震动记录数量提供依据。