Surface Texture Manufacturing Techniques and Tribological Effect of Surface Texturing on Cutting Tool Performance: A Review

The tribological characteristics of sliding surfaces have been remarkably improved by surface texturing. Surface texturing can be beneficial in many ways; for example, it can reduce friction and wear, increase load carrying capacity, and increase fluid film stiffness. The design process for surface texturing is highly correlated to the particular functions of any application for which texturing is required. Texture quality is greatly affected by manufacturing methods, therefore, it is important to have a detailed understanding of the related parameters of any technique.

The use of surface texturing to improve the cutting performance of tools is a relatively new application. These textures improve cutting performance by enhancing lubricant availability at the contact point, reducing the tool-chip contact area, and trapping wear debris. Reductions in crater and flank wear, friction force, cutting forces, and cutting temperature are the main benefits obtained by this technique. To date, surface texturing has been successfully used in drilling, milling, and turning operations.

This article provides an overview of the techniques that have been used in industry and research platforms to manufacture micro-/nano-textures for tribological applications, and it examines the effects of surface textures on cutting tool performance.     

The optical anisotropy and orientational order parameter of two mesogens having slightly different flexible side chain – a comparative study

Variation of the phase transition temperatures and existence of different number of mesophases, due to the changes of -CH₂ groups at the oxygen containing flexible side chain between two Schiff’s base liquid crystals compounds p-ethoxybenzylidine p-heptylaniline (EBHA) and p-butoxybenzylidine p-heptylaniline (BBHA) have been studied by using POM and DSC. Refractive indices as a function of temperature of these two compounds have also been measured by the well-known thin prism technique. To get the best accuracy of refractive indices data a comparison between the experimental data and theoretical values which are obtained from modified four-parameter model based on Vuks’ hypothesis have been done. A comparative study of some important parameters such as, optical anisotropy, orientational order parameters of these two liquid crystal compounds have also been conducted.     

三维形貌及颜色纹理的快速获取方法

为了在黑白摄像机中快速获取场景的三维形貌与颜色纹理,提出了绝对相位测量结合主动彩色照明的方法.首先向物体投影并拍摄两幅相移为1/3周期的条纹和一幅周期有微小差别的条纹图;然后分别向物体投射光强为给定强度的白、红及绿照明光,并拍摄图像.用改进的相移法求解第四幅图像与第一、第二幅变形条纹图中的相位;用改进的傅里叶变换法求解第四幅图像及第三幅变形条纹图中的相位;然后得出绝对相位值.最后利用第四幅图像与第五和第六幅图像求出场景反射的蓝色分量,并根据色度学原理恢复出场景的颜色纹理.实验表明,该方法在保证三维测量准确度的同时获得了高质量的颜色纹理,实现了30fps的三维数据及颜色纹理采集速度.     

基于小波变换和灰度共生矩阵的轮胎花纹检索

针对在用离散小波变换中提取纹理特征缺少纹理的空间分布特性问题,提出引入方向测度的灰度共生矩阵(Gray Level Co-occurrence Matrix,GLCM)与离散小波分解相互融合的算法,在低频子带上借助方向测度引入权值因子的方法提取灰度共生矩阵的六个统计量,用生成的综合特征来描述轮胎花纹的纹理构成,用欧式距离进行相似性度量。实验结果表明,融合算法能够有效提高检索效率,改进方法的检索效率优于用传统的灰度共生矩阵和小波变换提取纹理方法的检索效率。     

融合底层和中层字典特征的行人重识别

针对当前行人重识别方法采用单一底层特征识别率较低的问题,提出一种融合底层和中层特征的识别方法,由粗到精对人体目标进行匹配识别。首先提取目标的颜色直方图和纹理直方图进行粗分类;然后将人体目标分为头部、躯干和腿部3个部分。忽略包含信息量较少的头部,对躯干和腿部,提出一种中层图像块字典提取方法,并对照该字典生成中层特征,进行精确分类。底层特征结合中层特征使算法既具有较好的区分度,又具有良好的泛化能力。实验结果表明本文算法在VIPeR数据库上的n AUC比已有方法提高6.3%,对遮挡和背景粘连的鲁棒性更好。     

Two Theorems about Similarity Maps

One of the problems arising when exploring toponome or other multivariate-image data is the following: Given a family of n gray-value images of, e.g., a given sample of cell tissue, indexed by a collection of n proteins under investigation (so-called MELK data) — each single image representing the varying local concentration of one of those n proteins at the various sites (pixels) of the given sample, how should one quantify, for any two pixels (or clusters of pixels), the (dis)similarity between the corresponding “vectors” of local protein concentrations in question. Some (dis)similarity mappings defined on allowing for fast OpenGL texture mapping turned out to be useful in visual inspection of toponome data. Here, we derive two rather general results regarding similarity and dissimilarity mappings and, as a corollary, the fact that the functions that were used for visual inspection of MELK data are, indeed, metrics. We believe that our results are, however, also of more general interest within the ongoing program of elucidating the structure of metrics from a more abstract point of view. Received April 01, 2005     

Complexes in the Naphthoquinone Series: Crystal Structures,Electronic Structures,Stability

It is shown that the charge transfer is negligible in the ground state for organic charge transfer complexes between phenols and quinones. Our objective Is to determine the origin of the stability of the complexes. The geometric, electronic and energetic properties of these complexes were examined by three techniques, crystal structure determination by X-ray diffraction, spectrum and charge transfer calculation by quantum chemical methods, and lattice energy computation.     

Synthesis and properties of novel thermotropic liquid crystalline copoly(ester-imide)s

Four novel copoly(ester-imide)s based on 3,3',4,4'-biphenyltetracarboxylic dianhydride,bis(trimellitic acid anhydride) phenyl ester and di-p-aminophenyl ester of dicarboxylic acids were synthesized via two-step method in order to investigate whether two imide mesogenic units with different conformation and polarity could control the formation of LC-phase.Polarizes light microscopy(PLM) and differential scanning calorimetry(DSC) have shown that three polymers formed the nematic phase with thread schlieren...     

基于185例肺小结节CT图像灰度共生矩阵纹理特征的多水平模型研究

为探讨基于肺小结节CT图像灰度共生矩阵纹理特征的多水平模型,对北京友谊医院和宣武医院提供的185例2137张肺小结节CT图像提取4种灰度共生矩阵纹理特征。根据该类资料具有层次结构的特点,拟合多水平统计模型。结果表明,能量,熵和惯性矩,在患者水平上具有聚集性,且在良恶性肺小结节间的差异有统计学意义(P值均小于0.001),提示多水平模型可以灵活有效地处理肺小结节CT图像这类具有层次结构的数据,在一定程度上有利于早期肺癌的鉴别诊断。     

Growth and characterization of highly c‐axis textured SrTiO3 thin films directly grown on Si(001) substrates by ion beam sputter deposition

Highly c‐axis textured SrTiO₃ (STO) thin films have been directly grown on Si(001) substrates using ion beam sputter deposition technique without any buffer layer. The substrate temperature was varied, while other parameters were fixed in order to study effect of substrate temperature on morphology and texture evolution of STO films. X‐ray diffraction, pole figure analysis, atomic force microscope, and high‐resolution electron microscopy were used to characterize and confirm quality and texture of the STO films. The experimental results show that optimum substrate temperature to achieve highly c‐axis textured films is at 700 °C. The full width at half maximum (FWHM) of 002_STO was found to be 2° and fraction of (011) orientation was as low as 1%. The surface morphology was Volmer‐Weber growth mode with a small roughness ∼1 nm. The lowest leakage current density (5.8 μA/cm² at 2 V) and the highest dielectric constant (ε_STO ∼ 98) were found for highly c‐axis textured films grown at 700 °C. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)