首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
2D profile analysis has often in the past been considered sufficient to control the geometrical features of a surface and to ensure that they are compatible with the required functionalities. Yet, experience shows that 3D surface texture analysis is now essential wherever a complete assessment of the surface is required to enable the selection of the most appropriate surface texture to achieve a required functionality.This paper introduces measurement strategies and features considered as essential by SOMICRONIC when designing or developing 3D surface texture measuring instruments, knowing that the pursued aim is to assess the measured surface in a way to reveal the real surface. This is achieved without losing sight of existing ISO standardized concepts concerning surface texture profile analysis.Indeed, essentially for economical reasons, we consider that 31) surface texture stylus instruments must be designed to achieve classical surface texture profiles measurements and characterisations and to fulfil conditions and characteristics listed and described in existing surface texture ISO standards.We propose to develop in the next paragraphs, the following points:
• - Design of the data acquisition unit of a 3D surface texture instrument
• - Strategy for the measurement of the surface
• - Application of these concepts - Examples.
  相似文献   

2.
活塞-缸套系统是内燃机重要的摩擦副之一,活塞-缸套的表面质量影响着活塞-缸套系统的摩擦学性能,进而直接影响整机的服役性能。针对珩磨缸套表面 2D 粗糙度参数的局限性与表面粗糙度非接触检测方法研究,提出一种基于广义回归神经网络(GRNN)的珩磨缸套表面 3D 粗糙度图像检测方法。通过运用灰度共生矩阵(GLCM)提取缸套表面图像的纹理特征参数,并分析纹理特征参数与 3D 粗糙度间的相关性。以图像纹理特征参数作为输入,分别采用 GRNN 和多元回归分析 (MRA)建立 3D 粗糙度检测模型,通过与试验检测结果对比验证了模型的准确性。GRNN 检测模型获得的可决系数 R2均值 (0.962)优于 MRA 检测模型,且均方误差 MSE 均值(0.07)更小,与试验检测结果对比可知,采用 GRNN 建立的珩磨缸套 3D 粗糙度检测模型具有更高的精度,与实测 3D 粗糙度的相对误差均值为 7.9%。所建立的 3D 粗糙度检测模型具有较高的检测精度。  相似文献   

3.
基于模板匹配的思想,对二维图的自动生成算法进行了研究。首先将模板和待标注三维模型的点、线、面信息以及几何结构和拓扑结构以属性图的数据结构方式进行存储,通过面的广度优先搜索和边的广度优先搜索对存储的2个属性图进行匹配,再读取模板二维图上的标注等信息,利用二维图和三维模型的关联性和属性图匹配结果,对待标注三维模型进行自动标注,包括尺寸标注、表面粗糙度标注、形位公差标注等信息。  相似文献   

4.
The electro discharge machining (EDM) process produces surfaces that require some form of finishing operation. This is done in order to improve the surface texture and appearance of the component’s surface. However, it is also desirable to remove the white uppermost recast layer (produced by the EDM process) so as to improve the functional performance of the surface. Electropolishing or electrochemical polishing (ECP) is one technique that is used mainly to improve the appearance of steels as well as for passivation of stainless steels. However, this process is very complex in nature, and it is not well understood how the different process parameters influence the surface integrity of the component in salt solutions. The aim of this paper is to present the results of a preliminary design of experiment of an EDM+ECP process sequence using Taguchi methodology. 3D characterisation of the surfaces has been done and ANOVA technique has been used to assess the quantitative influence of the different process factors of ECP. The results have shown that the direct current is the most dominant factor in modifying the surface texture, especially the Sq and Sm 3D parameters. The interaction effect between current and distance between electrodes is relatively important as compared to the individual effect of the latter variable.  相似文献   

5.
表面织构在提升零件的耐磨性、界面接触的减摩性、材料表面的减阻性以及增强或降低材料的吸附性等方面展现出良好的效果.根据表面功能的不同,分别从耐磨表面、减阻表面、疏水表面、粘(脱)附性表面进行研究,综述了各种仿生织构的设计、加工及应用现状.研究发现,耐磨仿生织构图案尺寸相对较大,多在20μm以上,稳定的结构可以承受较大的外力;减阻疏水表面具有细微的突起状结构,能有效地通过微结构改变表面力学性能;粘附性表面得益于生物体微结构的形状尺寸,毛状微结构拥有良好的吸附性.加工方式上,激光刻蚀能精确控制加工尺寸和几何形状,化学刻蚀能得到更细微的表面形貌.仿生织构在机械密封、活塞环、刀具、滑动轴承及齿轮等应用上起到了良好的效果,但是截至目前,表面仿生织构研究较杂,并且未形成体系,相关设计和作用机理并不完善.通过分析仿生织构图案的功能性设计、多尺度复合加工和对零件服役性能的影响,为仿生织构图案的设计提供思路和更加科学的设计方法,并找到适合每种功能表面的加工技术.将仿生学应用于织构技术上,从生物体借鉴优良的功能特性,以期在工程上得到更广泛的应用.  相似文献   

6.
7.
We investigate the concept of surface roughness by assuming that z(x) verifies a Lipschitz condition in terms of variance var(z(x+Δ)−z(x))∝Δ2H with 0<H<1 and Δ→0. Such surfaces are only locally self-affine at scale where the prev relation is verified. The Lipshitz Hölder exponent H, which is directly connected to the surface fractal dimension D, is determined from the log-log plot of σ2-(L) versus the characteristic size L of the sampling area. Different results are presented. The first, which concerns simulated profiles derived from the Weierstrass function, gives some indication on the accuracy of the method. The other concerns 3D analysis of real sandblasted surfaces parallel to a simulated fractal surface. An extension of the theoretical analysis to certain non isotropic surfaces is also presented and applied to a real ground surface.  相似文献   

8.
三维高斯粗糙表面数字化模拟方法   总被引:1,自引:1,他引:0  
粗糙表面的数字模拟是工件接触性能研究的前提与基础。针对现有粗糙表面模拟方法的不足,提出一种新的三维高斯粗糙表面数字化模拟方法。根据设定的自相关函数矩阵构造求解转换矩阵的非线性方程组,采用改进的非线性共轭梯度法进行求解,根据得到的转换矩阵对随机矩阵进行变换,得到三维高斯粗糙表面的高度分布。最后利用提出的方法模拟了各向同性、异性两种高斯粗糙表面,通过对比分析模拟粗糙表面自相关函数,验证了该方法的有效性。  相似文献   

9.
贵金属超细丝材常用于精密电子功能器件的关键位置,但由于其加工成品尺寸微细传统技术无法准确表征超细丝材的微观精细结构。采用聚焦离子束-电子背散射衍射(FIB-EBSD)联用的超细丝材截面制样与表征方法,精确表征出了4种不同材质贵金属超细丝材的晶粒、取向、织构以及晶界等微观结构信息;而3D EBSD三维重构技术将微观结构分析实现为3D动态过程,更加直观地反应出超细丝材的真实微观结构信息。  相似文献   

10.
高度分布函数与自相关函数对表面粗糙度参数的影响   总被引:1,自引:1,他引:0  
林炜轩  王江涌 《表面技术》2017,46(1):241-249
目的研究具有不同高度分布和自相关函数的表面形貌的粗糙度参数变化。方法利用数字滤波法构造具有特定参数(如倾斜度、峰值、最快下降自相关长度和纹理高宽比、高度方差)的粗糙度表面,然后比较和分析不同类型形貌的参数。结果算术平均峰曲率不随高度分布函数和自相关函数变化,均方根斜率、界面开发面积比和峰密度随各种高度分布函数和自相关函数变化的影响较大。结论算术平均峰曲率不能表征高度分布和自相关函数。比较相同高度分布的表面形貌时,应对纹理高宽比、最快下降自相关长度、均方根斜率、界面开发面积比和峰密度进行比较。当比较不同高度分布的形貌时,应该对高度类参数倾斜度、峰值、高度均方根、最大高度、最大谷值和最大峰高进行比较。  相似文献   

11.
Object positioning and 3D modeling is not only a promising research direction in robot welding, but also an emphasis research field of machine vision. For objects lacking of textures on its surface, such as welding part, problem of 3D modeling of this kind of object can not be settled by traditional binocular stereo vision. In this paper, an approach to the problem is presented. A multibaseline stereo vision system with four verging configured cameras is proposed. Experiments show that we can get dense data points by the method, the results of surface reconstruction of objects with no matching texture on its surface is good. Experiment results confirmed that the method is valid in solving the problem of 3D surface reconstruction of objects lacking of matching texture.  相似文献   

12.
采用高速电镀技术在无间隙原子钢(IF钢)基板上镀锌,借助扫描电镜和取向分布函数研究镀锌层的微观形貌和织构。结果表?镀锌层由一系列倾斜于基体表面紧密排列的六方形片晶组成,初始电沉积时基体表面氢氧化锌的大量吸附抑制锌的三维形核,二维晶核的外延生长以及IF钢基板的{111}纤维织构促进镀锌层{11.5}锥形非纤维织构的形成。镀锌层呈锥形织构时,片晶的滑移面与基体表面呈一定角度,保证镀层在受到轴向应力时产生一定量的分切应力,从而有利于自身的塑性变形。  相似文献   

13.
通过正交试验,研究了峰值电流、脉冲间隔、开路电压、脉冲宽度等精细电规准在不同水平下,对NAK80材料准镜面电火花加工的三维表面参数(Sa、Sq和Sz)的影响。试验结果显示,在上述因素中,峰值电流和脉冲间隔对评价指标影响较大,脉冲宽度影响最小。通过方差分析,试验选定因素对评价指标的影响均非显著,并通过信噪比获得最优的加工参数。  相似文献   

14.
蒋虽合  毛卫民    杨平  叶丰 《物理测试》2014,32(3):14-19
用X射线直接比较法表征Fe-6.5%Si合金D03有序化,衍射强度受织构及三相多数衍射峰重叠影响而造成困难。选择D03{111}特征峰与三相重叠峰D03{444}、A2B2{222}比较,由于衍射面均为晶体学{111}晶面,结合有序化转变的特征可知该方法可避免织构的影响,两峰强度的比值实为D03相体积分数与表示其次近邻有序化程度参数的乘积。用方法表征了Fe-6.5%Si合金(温轧板A2相区退火后空冷)500℃时效过程中的D03有序化。结果表明,空冷首先使其转变为亚稳定的D03相,时效前期以B2相析出为主,后期两相分离及D03相有序化程度升高。分析认为该合金相的含量、有序化程度及分布形态均影响其磁性能。  相似文献   

15.
董雪峰  朱宁 《机床与液压》2017,45(18):111-116
在形状基不定情况下,对三维服装信息提取过程存在特征关联较弱,分割区域扩大等问题.为此,提出一种基于3D打印与三维图像处理的服装信息提取方法.首先对采集的服装三维图像进行纹理特征分割,图像序列自适应块匹配方法进行信息增强处理,然后采用桌面型3D打印技术进行服装设计中的图像三维重构,进行服装三维图像表面渲染,实现服装信息提取.最后通过仿真实验进行性能测试,结果表明:采用该方法进行服装信息提取,能准确反映服装的纹理信息和三维渲染信息,服装设计的色彩均衡性较好,有效指导服装设计优化.  相似文献   

16.
刘妍  刘悦  杨孔华  梁云虹  刘春宝 《表面技术》2023,52(7):299-305, 335
目的 制备可切换润湿性的智能超疏水表面,并探索该表面潜在的应用前景。方法 利用模板法,基于热响应形状记忆聚合物(Shape Memory Polymer,SMP)制备具有条状微结构阵列的可切换润湿性智能超疏水表面,并对其润湿性可逆转换能力及循环使用稳定性进行测试。结果 通过扫描电子显微镜观察到所制备表面微结构完整且轮廓清晰,液滴接触角在该表面可达到(150±3)°。通过加热使该表面达到玻璃化转变温度,此时对其施加外载荷使表面上条状微结构向一侧倾倒,由于微结构形态的改变,SMP表面疏水性减弱、水黏附性增强,再通过简单加热就可以使表面形态恢复至原始状态。通过试验测得环氧SMP的形状固定率为98.8%、形状回复率为96.3%,均达到95%以上,由于其优异的形状记忆特性,条状微结构的形态可以在原始直立状态和受到外载荷时的倾倒状态之间产生热响应而自由转变,且这种润湿性转换循环10次以上后,该表面依然保持着相对良好的润湿性可逆转换能力。结论 基于形状记忆聚合物制备出的可切换润湿性智能超疏水表面具有良好的润湿性可逆转换能力和循环使用能力,且在液滴微反应器、生物检测、可重写液体图案、无损失液滴转移和芯...  相似文献   

17.
Models, which are developed to determine the effective properties of thermal spray coatings, require the material properties of each constituent of the coating as well as the information about the spatial positions and the geometries of these constituents as input parameters. The complex microstructure of thermally sprayed Yttria-stabilized zirconia (YSZ) coatings consists of irregular voids which are distributed non-uniformly in the coating. It is a common practice in the literature to employ two-dimensional (2D) cross-sectional images of the coatings to derive the geometrical model of the microstructure and conduct the simulations in 2D. In the context of this study, contrary to the 2D approach, a new three-dimensional (3D) reconstruction approach has been developed to model the microstructure of thermally sprayed coatings in 3D. The effective properties of an YSZ coating have been calculated by means of asymptotic homogenization and virtual testing methods. The results of the models, which have been conducted in 2D and 3D, are compared with each other. Finally, the capabilities of these methods with respect to the modeling approach (in 3D and in 2D) are analyzed on the basis of reference measurements.  相似文献   

18.
This work investigates the mechanism of surface modification associated with the high-current pulsed electron beam (HCPEB) treatment of a D2 steel with increasing numbers of pulses. The surface layers were melted and resolidified but the treated surfaces showed very different features. This variation is essentially due to the different levels of homogeneity and carbide dissolution. It is demonstrated that the presence of carbides served as nucleation sites for the surface eruption phenomenon that creates craters on the surface. After a sufficient number of pulses, most of the carbides in the surface layer were dissolved and an almost crater-free homogeneous melted layer consisting of a very stable nano-austenite structure was formed. The HCPEB technique is thus demonstrated to be a versatile technique for surface microstructure modification involving, in the case of steels, austenite stabilization and ultrafine grain formation.  相似文献   

19.
The spatial structure of the surface layer, or texture is important for surface topography characterization. In many respects a texture determines contact behavior of the rough surfaces. Despite increasing role of the precision mechanics, the texture of engineering surfaces have not been adequately investigated. In this paper pattern recognition theory is introduced to perform surface textures classification. The height-coded images obtained by atomic force microscopy were used as initial data. The images represent the surface textures of various materials formed by various processes. We take the following procedure for the texture classification. First, the texture was characterized by a matrix of co-occurrence of image contrast. Next, the matrix is transformed into feature vector by the Karhunen-Loeve transformation. The feature vector was considered as coordinates of a point in the multidimensional feature space. The location of the point depends on the peculiarities of the surface texture. The set of the points form clusters that correspond to different classes of textures. The mutual arrangement of the points and structure of the clusters were analyzed by the multidimensional scaling procedure. It was founded that there is at least four classes of surface relives. The first three of them related to the properties of surface material and the last to the process of growth and crystallization on the interface of different materials.  相似文献   

20.
目的 探究叶片表面微细观结构对其润湿性的影响因素,以及控制机理。方法 以银杏(Ginkgo biloba,G. biloba)、二乔玉兰(Magnolia soulangeana, M. soulangeana)和二球悬铃木(Platanus acerifolia, P. acerifolia)3种处于落叶期初段的叶片样本为研究对象,测量3种叶片正背面的接触角,结合环境扫描电子显微镜图像,对比分析不同叶片正面和背面微细观结构及其对接触角的影响。结果 实验结果表明,落叶期初段银杏、二乔玉兰和二球悬铃木叶片正面均表现出弱亲水性,接触角分别为54.40°~66.80°、57.93°~74.87°、55.73°~82.23°。在银杏叶片背面,无论是顺纹理还是逆纹理方向,均表现出疏水特征,顺纹理方向的接触角为122.63°~135.10°,逆纹理方向的接触角为103.03°~134.13°。二乔玉兰和二球悬铃木的背面为中性润湿,接触角分别为82.87°~96.37°、90.50°~97.47°。结论 不同类型叶片的表面微结构显著不同,同种类型叶片正背面微结构也表现出较大差异。3种叶片背面接触角均...  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号