基于机器视觉铸件布氏硬度在线检测技术研究

为实现铸件布氏硬度的在线检测,应用基于机器视觉的布氏硬度自动测量系统采集压痕图像,研究压痕图像滤波、压痕图像轮廓直径提取、直径标定系数等算法。根据压痕图像的特点,提出基于粒子群的Snake模型压痕轮廓提取算法。引入压痕直径标定系数,解决了视觉测量中的压痕直径像素与压痕物理直径的换算关系,并对直径标定系数进行最小二乘法拟合,提高了测量精度。应用布氏硬度在线测量装置对180~210 HBW标准硬度块进行试验测试。试验表明:测量平均误差为0.72%,测量精度在±2 HBW之间,测量标准差为125 HBW,装置重复性好,精度高,完全能够满足铸件的布氏硬度在线检测要求。     

应用自调整蛇模型实现提取布氏硬度压痕圆

针对零部件的布氏硬度压痕图像,描述了一种应用蛇模型并结合形状相似性度量从而进行图像中的压痕圆提取的新算法.该新算法使用了改进后的蛇模型,可以利用预先知道的元件压痕的形状信息,基于形状相似性的度量,进行蛇模型的参数自调整,从而对元件的布氏硬度压痕图像进行有效的边缘检测,最终采用Hough变换成功实现了对布氏硬度压痕图像中的压痕圆的识别.实验结果表明,该方法可以实现了蛇模型参数的自适应设置,是一种有效的压痕圆提取方法.     

基于MATLAB图像处理的布氏硬度测量

提出了一种基于MATLAB图像处理技术进行布氏硬度测量的方法。通过对采集到的试件压痕图像进行特征提取和信息处理,识别出压痕的轮廓,并通过测量压痕的面积计算出压痕的直径,最后求得试件的布氏硬度。与传统的测量方法比,此方法具有测量速度快、结果准确、精度高等特点。     

CCD细分技术在布氏硬度测量系统中的应用

将图像处理中CCD细分技术应用到工业布氏硬度检测中,介绍一种基于CCD细分技术的布氏硬度测量系统进而检测试样压痕直径的方法。     

基于机器视觉的维氏硬度测量

设计了基于机器视觉的维氏硬度测量系统,提出了一种维氏硬度测量算法。基于位置聚类的方法,对压痕边界的边缘点进行有效提取与归类;先后两次基于最小二乘法对压痕边缘拟合,首先通过边缘拟合确定边缘直线的粗略位置,然后根据一次拟合方程剔除干扰点,再次拟合获得精准的边缘直线;为了有效的提高维氏硬度测量的精度,先对刻度线图像进行校正,获得了垂直于水平位置的刻度线图像后,再获取实际像素宽度。实践表明,该算法稳定性好、精度高,很好的满足了工业应用要求。     

浅谈布氏硬度试验中压痕测量装置的选用

通过对比使用三种不同的设备,测量布氏硬度压痕所得的硬度值,分析了读数显微镜、万能工具显微镜和全自动压痕测量系统在布氏硬度试验中对压痕测量结果的影响,最终得出了测量布氏硬度压痕时,根据测量对象选择合理的压痕测量装置的建议。     

基于Top-Hat的硬度压痕测量光照均匀度校正

针对维氏硬度压痕测量过程中由于物理光源照射产生的图像照度不均匀现象,研究了基于数字形态学的Top-Hat算法,对图像光照均匀度进行了校正。并针对传统Top-Hat存在的问题,提出了一种改进的算法。试验证明,该算法可靠有效,能够满足维氏硬度测量的工程实际要求。     

仪器化压痕技术的发展和面临的问题

介绍了采用仪器化压痕技术测量不同钢材及焊管的焊缝、热影响区和母材的抗拉强度的方法,还介绍了采用仪器化压痕技术,直接根据载荷和压痕深度计算布氏硬度的方法.     

黑色金属常用布氏硬度值压痕深度（h）计算表

测试布氏硬度值时的压痕深度(h)同压痕直径(d)同等重要,因为压痕深度(h)是较准确确定热处理零件加工余量的主要因素之一,但测量起来又不象压痕直径那样简单易行,通常使用计算方法来确定,而计算方法又较繁琐。因此,笔者按照有关文献     

维氏硬度试验压痕图的小波分析与自动计算硬度

介绍了维氏硬度测试原理；分析了采用经典的数字图像处理技术边缘分割算法对试验压痕边缘提取存在的局限，进而提出运用小波多分辨率理论分析试验压痕的取样信号，用最小二乘法拟合压痕边缘直线，从而提取显微硬度压痕边缘的新方法。研究表明，该方法实现了对显微组织维氏硬度试验压痕区域快速而准确地提取，并自动计算维氏硬度，所测得的硬度值和传统方法的测量值吻合。     

Problems in the measurement of Vickers and Brinell indentations

Hardness measurements by Vickers and Brinell indentations are liable to error, even when performed by experienced operators. The authors examine the problems involved in such measurements and the standards and specifications under which they are made. They conclude that some causes of error not yet fully understood and the effects of differences in optical microscopes are not taken into account. Greater standardisation of measurement systems has become necessary.     

HR-150A型洛氏硬度计的调修

本文结合HR-150A型洛氏硬度计的调修实践和过程，阐述了若干常见故障的解决方法，颇具实用性。     

焊接加重钻杆BoTn3000耐磨带堆焊工艺研究

对BoTn3000耐磨带堆焊工艺进行了研究,通过在各种材质上堆焊BoTn3000焊丝,进行一系列试验。试验结果表明,耐磨带外观质量良好、剖面质量状况良好、耐磨带硬度也符合SY/T6765（整体加重钻杆）标准要求。     

Influential factors on hardness uniformity of Vickers hardness blocks for high hardness range

Reference Vickers hardness blocks for high hardness range were developed from WC 9–Co and WC 6–Co mixtures by two different processes of powder metallurgy, conventional liquid phase sintering in hydrogen and vacuum-sintering with subsequent hot isostatic pressing in one cycle, sinter-HIP, in order to analyse the appropriateness of the manufacturing process and the influence of starting characteristics of the mixtures on hardness uniformity and overall metrological characteristics. WC powder of 150 nm grain size and 2.5 m²/g specific surface area with the addition of grain grow inhibitors was used as starting material. The emphasis of the research was placed on hardness uniformity of the test surface as it is the most important property placed on hardness blocks. For that purpose the surface of the blocks was divided into radial and circumferential divisions, forming different sections on the block surface. Hardness measurements were performed in each section with HV1 measuring method. A total of 40 indentations were performed, based on which the conclusions about hardness uniformity of Vickers hardness blocks were drawn. Hardness measurements and uniformity were tested by analysis of variance, ANOVA, for single factor in order to determine if significant hardness variations across the block surface were present. From the research conducted it was concluded that hardness distribution across test surfaces of Vickers hardness blocks had a trend according to a process of manufacturing and the amount of binder in the WC–Co mixture. The best material and metrological characteristics were obtained on the block manufactured by sinter-HIP with 9 wt.% Co.     

Mechanics analysis and simulation of material Brinell hardness measurement

Material Brinell hardness values are usually measured by force loading Brinell hardness testers. In this paper, firstly, based on experiment data and theoretical analysis, not only the relationship between Brinell hardness and mechanical properties of the measured material is discussed, but also all measurement uncertainty sources are precisely calibrated. Secondly, force loading characteristics of the Brinell hardness measurement are described and a finite element analysis for the whole Brinell hardness measurement process is introduced. Thirdly, to acquire theoretical measurement uncertainties and the reliable Brinell hardness values of the material under analysis, Monte Carlo method is applied to simulate Brinell hardness experiments. At last, several sets of experiments are carried out on HB-3000C, the Brinell hardness results acquired by this proposed novel mechanics analysis method and practical experiments shown to be consistent, and the validity of the proposed method is attained.     

长管拖车钢瓶硬度控制范围和验收标准的探讨

硬度检测由于操作简便易行且不损伤钢瓶,因此成为制造过程中检验钢瓶热处理性能和定期检验过程中评定钢瓶安全性能的常用手段.结合相关标准给定的材料抗拉强度和硬度的相关关系,通过对现场数据和材料质量证明书进行统计分析,拟合出了抗拉强度和硬度关系曲线,由该拟合曲线和制造企业给定的抗拉强度范围,得出了长管拖车钢瓶的硬度控制范围和验收标准,为大容积无缝钢瓶的生产质量控制和检验检测提供了可靠依据.     

Evaluation of abradable seal coating mechanical properties

Three proprietary plasma-sprayed coatings, based on Ni–graphite, Al–Si–graphite and Al–Si–polyester, were chosen for evaluation by the use of a (low speed) scratch tester, as a means of assessing the performance of abradable coatings. The scratch test behaviour was also correlated with the mechanical properties of the coatings (elastic modulus, microhardness and ultimate tensile strength). The results obtained were compared with those from industrial trials, to ascertain if the scratch test could be used as a relatively cheap and effective alternative to expensive engine trials. We have shown that the Progressive Abradability Hardness, abbreviated below as PAH, can be utilised as a measure of abradability in the scratch test, and can be related to the mechanical properties, in a manner consistent with engine test-bed findings. We have also found that the abradability and the PAH can change with scratch length due, we believe, to coating compression and densification ahead of the slider. In this work, the PAH has been related to coating hardness, ultimate tensile strength and elastic modulus.     

基于人工神经网络的里氏硬度转换研究

随着里氏硬度测量的发展,里氏硬度的转换变得越来越重要。针对里氏硬度转换的误差较大的问题,本文提出采用人工神经网络的方法来实现里氏硬度到其他硬度的转换,并说明了在单片机中利用人工神经网络实现里氏硬度转换的方法。