基于NC机床的模具三维曲面磁力研磨技术

简述了在NC机床加装带有励磁线圈的工具磁极进行模具曲面磁力研磨的加工原理,详细介绍了磁力研磨模具曲面的工艺准备、磁性磨粒、工艺参数的选择以及数字化研磨轨迹的规划和生成方法.     

基于并联机器人模具型腔磁力研磨光整加工

为了实现复杂曲面模具表面高质量高效率磁力研磨光整加工,进行磁力研磨光整加工的实验研究,对复杂曲面模具自动化磁力研磨光整加工进行了初步探索;从理论上研究了自由磨粒磁力研磨光整加工的机理与特点,并针对不同形状的加工对象,实验研究了磁感应强度、研磨间隙、磨粒粒度以及研具表面形状对磁力研磨光整加工的影响及其变化规律     

模具自由曲面自动研磨加工实验研究

设计了一种用于模具自由曲面自动研磨加工的实验装置，由控制系统和执行机构组成，该装置安装在加工中心主轴上，研磨路径由加工中心控制。在优化工艺参数基础上，通过自动研磨实验研究，得到了研磨过程中实验规律，为模具曲面自动精加工向实用化发展奠定了基础。     

磁性磨料电解研磨在冲压模具加工中的应用

本文对一种新兴的冲压模具特种加工方法——磁性磨料电解研磨加工作了详细介绍。文中通过基本原理、加工特点及其影响因素、设备和工具组成、生产应用等方面的阐述,并结合图表,对冲压模具制造过程中的磁性磨料电解研磨加工工艺进行了说明。本文对冲压模具的具体生产有一定的指导意义。     

k9光学玻璃磁性研磨抛光的工艺研究

对于以往k9光学玻璃研磨抛光存在的问题,提出将磁性研磨加工方法应用在光学玻璃的研磨抛光上。该方法采用铣床主轴带动磁极旋转,从而使磁极带动磁性磨料来对工件的表面进行研磨加工。利用已研制的数控磁性研磨铣床,通过实验研究影响工件表面粗糙度的各个工艺参数,最终获得了k9光学玻璃凹面磁性研磨的优化工艺参数。     

自动超声电火花复合加工模具曲面的干涉预报

提出一种由机器人技术和超声电火花复合抛光机等组成的自动研磨加工系统 ,对在模具曲面加工过程中出现的工具与工件之间可能产生的局部干涉现象进行了研究 ,通过干涉回避技术建立复合精加工表面质量的控制模型 ,并在试验中证实了理论的正确性。     

铁基白刚玉磁性磨料的制备工艺

磁性磨料的研磨性能是影响磁力研磨应用的一个关键因素.以铁基白刚玉磁性磨料的制备工艺为例,重点研究烧结法制备磁性磨料过程中压制力、烧结温度、升温速度等因素对磁性磨料致密度的影响.通过对比实验,对烧结法制备铁基白刚玉磁性磨料的工艺参数进行了优化设计.实验证明:压制力一般保持在175～200 MPa,升温速度为3～4℃/min,达到1 200℃后保温150 min,铁基白刚玉的铁磁相与磨料相结合最佳.烧结后可以消除白刚玉加工过程中产生的应力,弥合加工过程中所产生的磨粒微裂痕和晶体本身的缺陷,大幅度提高磁性磨料的使用寿命.     

模具数字化磁力研磨加工中研磨运动轨迹的研究

介绍了模具制造过程中,模具表面数字化磁力研磨加工的原理和特点,分析了曲面磁力研磨加工轨迹对研磨质量的影响,提出了相应的解决办法。     

模具曲面光整加工中数字化磁力研磨技术

本文针对模具制造过程中模具表面的自动化研磨光整加工的问题，介绍了一种数字化磁力研磨技术。简述了其原理，详细论述了数字化研磨三维加工模型的获得、工艺参数的选择、数字化研磨轨迹的生成方法以及专用和改装的数字化磁力研磨设备等关键技术，证实利用数字化磁力研磨可以对模具曲面进行有效地自动化光整加工。     

磁力研磨加工K9光学玻璃的实验研究

目的提高K9光学玻璃研磨加工的材料去除率及表面质量。方法采用改进的磁力研磨工艺对玻璃表面进行加工,改变相对运动方式,磁力研磨过程中工作台及工具头同时转动。以材料去除率及表面质量为研究目标,研究磁力研磨主要工艺参数的影响。优选了工具头转速、研磨压力、工作台转速、磨粒大小等关键参数,进行了一系列实验。利用KEYENCE VK系列的形状测量激光显微镜观察不同加工条件下的微观形貌,并分析主要加工参数对表面质量的影响。利用JJ124BC双杰电子分析天平对加工前后进行称量,计算材料去除率。结果在本实验装置下,采用工具头转速为1500 r/min、工作台转速为200 r/min、加工间隙为2 mm、磨粒目数为150目的工艺参数时,加工试件的表面粗糙度值Ra达到120 nm。从3D微观形貌来看,该参数条件下可以获得更好的表面质量,表面一致性较好,最高点的值为2.8μm。结论经过改进的磁力研磨加工方法,研磨速度及研磨压力仍是关键的加工因素,K9光学玻璃的加工实验对硬脆材料的加工具有一定借鉴意义。     

A surface topography model for automated surface finishing

This paper presents a 3-D surface topography model that has been developed to analyze and represent the spectrum of components of surface topography ranging over shape, waviness and roughness in a way suitable for generating macro- and micro-level automated surface finishing commands. Results of 3-D surface topography analysis such as comparison of desired and actual surface topography must be combinable with surface finishing processes in ways that permit the generation and output of commands, thereby causing the actual surface topography to converge towards a desired surface topography.An efficient filter, 3-D motif filter, with optimal cut-off length has been developed for roughness elements first, and then extended to waviness elements.A neutral surface shape method approximation for the machined surface shape has been proposed. Surface shape error is then eliminated as the deviation of the approximated neutral surface shape and the design surface shape.After the motif filtering, a B-spline fitting is used to represent the surface topography data within each 3-D motif cell after surface shape regeneration. The data reduction technique in 3-D motif filter methods has been shown significantly by reducing a great amount of inspection data to several elements and each element is suitable for use in surface finishing control. Some limitations of the 3-D motif filter method are discussed by the selection of different machined lay direction. The use of the developed 3-D surface topography model on automated surface finishing processes was performed on a platform constituting a 3-axis CNC machining center, inspection probe and a electrical grinder installed on the spindle housing of CNC machining center. Experimental results from an automated surface finishing system (ASFS) with in-process surface topography acquisition for mold and die finishing have shown the optimistic use of the developed surface topography model for industrial applications.     

Specialized induction machines for deep surface and surface hardening

Conclusion Experience has shown the economic desirability of production and introduction into the national economy of specialized hardening equipment such as induction machines. Such machines are especially effective in heat treatment of heavily loaded machine parts, including those of complex configuration and which are highly metal consuming.For the purpose of rational and effective utilization of metals further broadening of investigations, development, and production of specialized equipment together with the production of universal purpose machines is desirable.Inductor Novozybkov Plant. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 8, pp. 50–54, August, 1987.     

纳米金刚石表面改性处理及表面结构表征

利用强氧化性酸和真空热处理对尺寸为50nm的金刚石微粉进行表面改性处理并进行研究。通过XRD、Raman、TG-DTA以及FTIR等分析手段测试了纳米金刚石的表面结构和耐热性能。研究结果表明:这一工艺可以去除纳米金刚石表面大部分吸附杂质,提高耐热性能,但羟基和羰基等基团难以去除。     

Fabrication of super-hydrophobic surface on copper surface by polymer plating

The 6-(N-allyl-1,1,2,2-tetrahydroperfluorodecyl)amino-1,3,5-triazine-2,4-dithiol monosodium) (ATP) was used to fabricate polymeric thin film on pure copper plate to achieve super-hydrophobic surface. The copper plates were pretreated to gain rough surfaces by chemical etching before polymer plating. The polymer plating process of ATP on copper in Na₂CO₃ aqueous solution and the growth mechanism of poly(6-(N-allyl-1,1,2,2-tetrahydro-perfluorodecyl) amino-1,3,5-triazine-2,4-dithiol) (PAT) thin film was studied by means of cyclic voltammetry. The polymeric film was investigated by using X-ray photoelectron spectroscopy (XPS), and the etched surfaces were observed by atomic force microscopy (AFM). A contact angle meter was applied to measure the contact angles with distilled water drops at ambient temperature. The experimental results indicated that the polymeric film formed on rough copper surface exhibits super-hydrophobic property with a distilled water contact angle of 155°. The wettability of copper surfaces was discussed on the basis of both Wenzel and Cassie theories. The etching and polymer plating processes are time-saving, inexpensive, environmental and fairly convenient to carry out. It is expected that this technique will advance the production of super-hydrophobic materials with new applications in large scale. Moreover, this kind of thin film can be used as a dielectric material due to its insulated feature.     

Nondestructive characterization of the surface integrity of cold surface hardened components

Nondestructive characterization of surface and subsurface properties is of increasing interest in industry and science. As destructive methods are inadequate for testing large devices (e.g. gear wheels for wind engines) or small series, nondestructive techniques for the assessment of their surface integrity are mandatory. Especially surface hardened components have to be examined in practice, as they tend to show varying properties regarding surface hardness, hardness penetration depth and residual stress profiles. Since the surface integrity has a major influence on the functional performance of components, assessment and monitoring of the surface properties is crucial. In this study, the results of a new technique for surface hardening (cold surface hardening) were investigated for the first time applying an emerging nondestructive measuring method: the photothermal near-surface layer characterization.     

Superhydrophobic fluoropolymer-modified copper surface via surface graft polymerisation for corrosion protection

With the objective of developing materials with repellent surfaces by combining both low surface energy and rough structure, superhydrophobic fluoropolymer films were prepared via surface graft polymerisation from copper substrates. A vinyl-terminated trimethoxysilane was firstly immobilised on the etched-copper surface to introduce active carbon–carbon double bonds. Subsequent graft polymerisation of 2,2,3,4,4,4-hexafluorobutyl acrylate (HFBA), in the presence of a polymerisation initiator 4,4′-azobis-(4-cyanpentanoic acid), yielded the fluoropolymer films on the copper substrates. The resultant P(HFBA)-grafted surfaces not only exhibited desired superhydrophobic property with water contact angle above 150°, but substantially improved the corrosion resistance of copper substrates.     

矿物的解理性质及表面能：各向异性的表面断裂因素

利用Materials Studio软件计算研究几种属于立方、四方、六方或单斜晶系等不同晶系的典型硫化矿、氧化矿和含氧酸盐矿物的表面断裂键性质,分析这些矿物的解理特性,并建立表面断裂键密度与表面能的关系。结果表明：表面断裂键性质可以用来预测大部分矿物的解理特性,预测结果与文献报道一致。对于某种矿物,表面断裂键的密度与表面能成正比,决定系数R^2皆大于0.8,表明表面断裂键的密度大小是决定表面能的关键因素。同时,表面断裂键的数目可用来预测矿物表面的稳定性及表面原子的反应活性。     

High-temperature surface alloying of nanocrystalline nickel produced by surface mechanical attrition treatment

A nanocrystalline surface layer is synthesized in Ni by surface mechanical attrition treatment (SMAT). The characterization of microstructure and composition indicates that foreign elements from hardened balls can permeate and diffuse into the surface layer during SMAT, which can further diffuse and homogenize in the surface layer when annealing at high temperature, leading to formation of new alloy. Foreign elements permeating into the surface layer during SMAT followed by diffusing and homogenizing at high temperature provide an alternative effective technology for surface modification.     

Quantitative evaluation of die casting surface defect severity by analyzing surface height

It is necessary in factories to assess the severity of the surface defects of castings, as a slight surface defect will be taken as qualified when it brings no bad effect or it can be removed by the subsequent processing. In practical production, professional technicians visually inspect the surface defect severity according to their individual experience. Therefore, it is difficult for them to maintain the same standard and accuracy in the subjective, tedious and labor-intensive work. Recently, image processing techniques based on optical images have been applied to achieve better accuracy and high efficiency. Unfortunately, optical images cannot directly quantify surface depth, which works as a crucial factor in the practical assessment of surface defect severity. The surface roughness evaluation algorithm, which takes into account of both area and depth information of the assessed surface, was applied to directly characterize surface defect severity based on surface asperity rather than optical image. The results using standard casting pieces show that surface defect severity has no apparent dependence on surface roughness. However, the subsequent results show that the root-mean-squared-deviation (RMSD) of surface gradient of flow line defects positively correlates with the increase of defect severity. The other types of defect do not present such tendency. Thus, practical workpieces with flow line defects on the surface were used to verify the universality of this tendency. The results show that surface roughness of an unqualified workpiece is larger than that of a qualified workpiece after surface slope adjustment, but presents no obvious coincidence before the adjustment. In contrast, the RMSD of an unqualified workpiece, no matter before or after the adjustment, is larger than that of a qualified one.     

Problems in surface metrology

Calibrations of surface finish measurements in our laboratory rely on a set of master step-height specimens ranging in size from 29 nm to 152 μm. These step-height speciments are calibrated in turn by different techniques depending on the step height itself. In order to establish precise values for step heights smaller than 1000 nm, we have established a goal to calibrated several new step-height specimens in this range by three different independent techniques. These are phase shifting interferometric microscopy, a calibrated atomic force tecroscpe (C-AFM), and a high-resolution stylus instrument calibrated by another calibration step. If we can measure precise values of the step height by these different techniques and achieved good agreement, the step-height speciments would then become precise calibration masters.