超声显微镜技术在铜/铝摩擦焊质量控制中的应用

铜/铝摩擦焊广泛用于电力行业接线端子的制作，其焊接质量直接影响着电力系统的安全运行。通过理论分析及试验方法探讨了超声波显微镜技术在铜/铝摩擦焊质量控制中的应用可行性，同时进行超声显微镜检测试验，发现将超声显微镜技术应用在铜/铝摩擦焊检测中，检测灵敏度高、分辨率好、检测结果直观。     

用计算机图形处理软件定量分析SEM图像

用图形处理软件PHOTOSHOP对SEM图像进行图像定量分析，对高温合金K23σ析出相的体积分数和M8钢样的夹杂物颗粒尺寸进行了定量测定。结果表明，该方法操作方便，有一定的可行性。     

长悬臂三坐标测量机测端抖动实时修正系统

长悬臂三坐标测量机是用来在线测量工字钢结晶器内腔尺寸的，测量运行过程中，由于长悬臂及测杆的弱刚性和各轴传导结构的非理想性，造成测杆端部的空间抖动，直接影响测量精度。论文结合有限元分析了产生抖动的原因，基于面阵CCD和图像处理技术，建立检测系统并建模，实时检测测头触发瞬间测杆端部在空间3个方向的抖动位移，在VC＋＋6．0环境下编写软件，通过软件计算实时修正抖动对测量精度的影响。并通过试验验证了该系统的实用性。     

Exploring thermal spray gray alumina coating pore network architecture by combining stereological protocols and impedance electrochemical spectroscopy

Complex multiscale pore network architecture characterized by multimodal pore size distribution and connectivity develops during the manufacture of ceramic thermal spray coatings from intra- and interlamellar cracks generated when each lamella spreads and solidifies to globular pores resulting from lamella stacking defects. This network significantly affects the coating properties and their in-service behaviors. De Hoff stereological analysis permits quantification of the three-dimensional (3D) distribution of spheroids (i.e., pores) from the determination of their two-dimensional (2D) distribution estimated by image analysis when analyzing the coating structure from a polished plane. Electrochemical impedance spectroscopy electrochemically examines a material surface by frequency variable current and potential and analyzes the complex impedance. When a coating covers the material surface, the electrolyte percolates through the more or less connected pore network to locally passivate the substrate. The resistive and capacitive characteristics of the equivalent electrical circuit will depend upon the connected pore network architecture. Both protocols were implemented to quantify thermal spray coating structures. Al₂O₃-13TiO₂ coatings were atmospherically plasma sprayed using several sets of power parameters, are current intensity, plasma gas total flow rate, and plasma gas composition in order to determine their effects on pore network architecture. Particle characteristics upon impact, especially their related dimensionless numbers, such as Reynolds, Weber, and Sommerfeld criteria, were also determined. Analyses permitted identification of (a) the major effects of power parameters upon pore architecture and (b) the related formation mechanisms. This article was originally published inBuilding on 100 Years of Success, Proceedings of the 2006 International Thermal Spray Conference (Seattle, WA), May 15–18, 2006, B.R. Marple, M.M. Hyland, Y.-Ch. Lau, R.S. Lima, and J. Voyer, Ed., ASM International, Materials Park, OH, 2006.     

基于改进C-V方法的焊接图像识别

基于简化的Mumford—Shah水平集图像分割模型，Chart—Vese提出了不依赖于图像边缘的水平集图像分割算法（C～V方法）。文中对该算法进行了深入研究，指出了原方法存在的缺陷，即处理的图像必须具有比较明显的特征，分割目标过多且较为分散时则很难得到理想的结果，每次迭代过程都需要对所有的图像数据进行计算，比较费时。根据焊接图像本身的特点给出了三点改进，即强化特征模型的修正、多尺度快速算法和全局特性抑制。应用改进的算法，进行了模拟对比试验和真实熔池图像识别的试验。结果表明，该方法能识别出焊接图像连续轮廓，提取有用信息，具有良好的适应性，同时为复杂图像的特征物体目标提取提供了可行的思路。     

面状缺陷超声B扫描检测图像增强研究

针对面状焊接缺陷超声B扫描检测图像受噪声污染造成的质量下降问题,利用多尺度小波分析方法,对超声B扫描图像进行了增强处理.分析了缺陷信号和噪声的小波变换特性,分别在软、硬阈值函数条件下,采用固定阈值、Stein无偏似然估计阈值、混合型阈值、极大极小准则阈值等方法进行了信号增强处理,比较了不同阈值方法小波变换的处理效果.结果表明:小波变换方法能有效地提高超声B扫描图像质量,硬阈值条件下固定阈值小波变换方法的图像增强处理效果较好.     

铝液充型过程水模拟计算机可视化技术

采用可视观察方法研究了铝液充型过程的二维流动状态,并与水模拟实验进行了对比分析,通过调整水粘度来保证水模拟过程与铝液充型过程的相似性.以PIV技术为基础,运用数字视频处理中的运动补偿技术,选用NCCF准则和三步搜索法对低压铸造浇注系统水模拟充型过程的内部二维流场进行了计算和分析;运用边缘检测及提取技术,选用Roberts边缘检测算子对低压铸造浇注系统水模拟充型过程的二维表面流场进行了计算和分析,实现了水模拟过程的量化分析.     

Morphological analysis and classification of types of surface corrosion damage by digital image processing

This paper examines a new concept of corrosion surface damage analysis by using the digital image processing. Corrosion phenomena are analyzed using a digital value for morphological surface damages instead of electrochemical methods. Initial images are characterized by three categories: color, texture and shape features. To calculate corrosion surface damages color we use the interpretation of HIS model. For the texture attributes, the method of co-occurrence matrix is used. Five types of corrosion damage are examined. Multidimensional scaling procedure is used to define the classification plane. This study suggests a probabilistic method of decision-making. This analysis develops a method for automated identification system of corrosion damages and is supposed to be more advantageous than that of electrochemical techniques.     

MAG焊熔池图像特征及可用信息分析

针对MAG焊焊接过程的特点,采用被动式视觉传感的方式,利用近红外CCD摄像机,配合1064nm窄带滤光片和0.1%中性减光片组成的复合滤光系统,很好地排除了弧光的干扰,采集到大量高清晰的MAG焊短路过渡、射滴过渡、射流过渡熔池图像.利用数字图像处理技术对熔池图像进行图像处理,并提取出反映焊接质量的图像特征信息.对于单幅熔池图像进行了灰度分析,并提取了三条熔池图像等值轮廓线;对于连续多帧熔池图像,提出了利用熔池图像差影检测和熔池图像平均灰度来研究MAG焊焊接过程的新思路,为熔化极气体保护焊焊接过程质量控制奠定了基础.     

十二胺在碳钢表面的吸附行为

利用原子力显微镜（AFM）、动电位扫描及润湿角测量等手段研究了盐酸溶液中十二胺在碳钢表面的吸附行为及其对碳钢腐蚀行为的影响。结果表明：十二胺在碳钢表面形成了单分子吸附层。其对碳钢的缓蚀机理主要为“几何覆盖效应”，一个十二胺分子平均可以取代2．32个水分子；碳钢表面的润湿性随缓蚀剂浓度的增大而减弱。AFM电流图像显示，碳钢表面有十二胺吸附的部位导电性能明显减弱；AFM力—距离曲线表明，碳钢表面有缓蚀剂吸附的部位呈现出明显的黏附力。