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。     

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。     

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.     

反求工程在磁粒研磨技术中的应用

对反求工程在磁力研磨中的应用给予了充分的论证,并找出了二者的结合点,解决了磁力研磨在复杂曲面加工中难以确定磁极运动轨迹的难题,该技术的完善对于实现模具型腔精加工的自动化具有重要的意义。     

小孔内表面磁力研磨加工技术研究进展

磁力研磨加工是提高小孔内表面质量的一种重要光整技术,利用该技术能高效提升小孔类零部件在极端环境下的使役性能。针对小孔内表面的磁力研磨光整加工,按其发展历程对磁力研磨加工技术进行总结,归纳了磁性磨粒研磨、磁针磁力研磨、液体磁性磨具研磨、超声辅助磁力研磨和电解磁力复合研磨等加工方法的技术特点,并分析评述了其局限性。对磁力研磨加工过程中材料去除机理进行了研究,材料主要以微量切削与挤压、塑性变形磨损、腐蚀磨损、电化学磨损等方式去除,材料种类不同,去除机理也不同。其中,硬脆性材料主要以脆性断裂、塑性变形和粉末化的形式去除;塑性材料在经历滑擦阶段、耕犁阶段和材料去除阶段后主要以切屑的形式去除。此外,还对磁力研磨加工过程中的材料去除模型进行了研究,对单颗磁性磨粒材料去除模型和“磁力刷”材料去除模型进行了分析讨论。最后,对磁力研磨加工技术今后的研究发展给出了建议并进行了展望。     

磁力研磨加工技术

阐述了磁力研磨加工的原理、装置及特点 ,概述了磁性磨料的特性和制作方法 ,论述了各种因素对磁力研磨加工的影响规律 ,介绍了国内外研究状况及应用现状 ,探讨了磁力研磨加工技术的发展趋势     

磁力研磨加工技术

阐述了磁力研磨加工的原理、装置及特点,概述了磁性磨料的特性和制作方法,论述了各种因素对磁力研磨加工的影响规律,介绍了国内外研究状况及应用现状,探讨了磁力研磨加工技术的发展趋势。     

基于磁力研磨技术的模具精加工自动化的应用研究

针对模具精加工自动化的问题进行了深入探讨,提出了基于磁力研磨技术和数字化仿形的模具精加工自动化的技术路线.利用磁力研磨的柔性、自适应性、加工的精度高等技术特点解决了传统刚性刀具难于加工三维复杂曲面的难题;由于模具型面的不规则性,给数控程序的编制带来了极大的困难,利用自己开发研制的集测量、仿形、加工代码的生成为一体的磁粒研磨机床很好地解决了这一难题;由于测量和加工在同一机床,避免了工件的重复装卡和重复定位;磁极与工件之间的加工间隙靠测头与磁极半径的差值来保证;同时对该方案所涉及的一些关键技术进行了研究,并给出解决措施.通过实验验证,利用磁力研磨技术和数字化仿形是解决模具精加工完全自动化的有效方法之一.     

磁力研磨工艺对整体叶盘表面完整性的影响

针对铣削加工对整体叶盘零件表面完整性控制不能满足使用要求的难题,利用磁力研磨所特有的柔性、自适应性、可控性等优点,研发了一种基于机器人的自由曲面磁力研磨装置,对整体叶盘零件进行加工试验。试验结果表明:经过磁力研磨后零件的表面粗糙度数值大幅度降低;铣削加工残留下来的加工纹理基本去除;原始表面上的微裂纹减弱或彻底消除;近表层原始显微组织中的变质层被部分去除;残余应力也明显减小。由此表明磁力研磨加工工艺能够提高整体叶盘的表面完整性,从而可以提高零件的疲劳强度和使用寿命。     

Investigation of the finishing characteristics in an internal tube finishing process by magnetic abrasive finishing combined with electrolysis

In this research, the finishing characteristics in a tube's internal finishing process using the method of magnetic abrasive finishing (MAF) combined with electrolysis has been studied. Electrolysis produces an aluminium oxide film that accelerates the removal of the initial hairline morphology on the surface. Subsequently, the film is removed with MAF. This process significantly minimises the surface roughness in a reduced time. The way the finishing conditions, such as the pole–pipe gap, iron particle size and abrasiveness combinations, and processing time affected the surface morphology in the MAF machining process has been particularly examined. The surface roughness was measured and images of the finished surfaces were recorded to study the morphology changes. Prolonged electrolysis finishing was seen to deepen the oxidation film and pits, which adversely affects the surface. This evidence suggests that the pit residuals contribute to higher surface roughness values.     

Ultrasonic assisted magnetic abrasive finishing of hardened AISI 52100 steel using unbonded SiC abrasives

Ultrasonic assisted magnetic abrasive finishing (UAMAF) integrates the use of ultrasonic vibrations and magnetic abrasive finishing (MAF) process to finish surfaces to nanometer order in a relatively short time. The present study emphasizes on the fabrication of UAMAF setup. Using this experimental setup, experimental studies have been carried out with respect to five important process parameters namely supply voltage, abrasive mesh number, rotation of magnet, abrasive weight percentage, and pulse on time (T_on) of ultrasonic vibrations selected based on literature available in the area of MAF process and ultrasonic generator controls. Percentage change in surface roughness (?Ra) for AISI 52100 steel workpiece has been considered as response and unbonded SiC abrasives are used in the work. The experimental results showed that the UAMAF process has better finishing potential as compared to those obtainable by using MAF process for similar processing conditions. The surface roughness value obtained by UAMAF was as low as 22 nm within 80 s on hardened AISI 52100 steel workpiece using unbonded SiC abrasives. Scanning electron microscopy and atomic force microscopy studies were carried out to feel the surface texture produced and to identify finishing mechanism.     

钛合金管内表面的电化学磁力研磨复合光整试验

针对热挤压成型对钛合金管的内表面会产生微裂纹、褶皱、毛刺等表面缺陷的问题,提出了一种高效率的电化学磁力研磨复合光整加工方法。设计了电化学磁力研磨复合光整加工的实验装置,分别与纯磁力研磨加工和纯电化学加工进行了光整加工试验对比,检测分析了不同工艺加工前后表面的粗糙度、微观形貌、摩擦磨损行为、表面残余应力和能量谱。结果表明:在相同的加工时间内,与单纯电化学加工和磁力研磨加工相比,电化学磁力研磨复合光整加工的表面粗糙度Ra可达到0.2μm,材料去除量和加工效率显著提高;表面显微形貌要明显优于其他两种加工方式;且加工后表面很好地维持了原有材料的化学成分和表面性质;能够使表面由拉应力转变为约–200 MPa的压应力状态,从而获得更好的表面应力状态。     

Electrolytic magnetic abrasive finishing

Electrolytic magnetic abrasive finishing (EMAF) is a compound finishing process, involving traditional magnetic abrasive finishing (MAF) and an electrolytic process. The aim of including the electrolytic process into the EMAF system is to produce a passive film (or oxide film), which is much easier to remove than the original metal surface during processing. Moreover, in the presence of both electric and magnetic fields, the negatively charged ions move toward the anode surface along a cycloid curve by the action of the Lorentz force. Under appropriate operating conditions, this phenomenon promotes electrolytic effects, resulting in a further increase in finishing efficiency, yielding a superior surface. This study describes the principles of the process, the finishing characteristics of surface roughness and material removal, and the associated mechanisms. Experimental results show that the EMAF process yields quite excellent finishing characteristics, better than those obtained by MAF, especially with a high electrolytic current. The process parameters such as electrolytic current, electrode gap, magnetic flux density, and rate of workpiece revolution must be appropriately fitted to obtain a superior refined surface with high efficiency.     

Surface finishing of cobalt chromium alloy femoral knee components

This paper describes the modification of surface roughness and lay of cobalt chromium alloy femoral knee components by magnetic abrasive finishing (MAF), including clarification of the MAF surface-processing mechanisms. The MAF process creates characteristic surfaces by micro-cutting of abrasive pressed by magnetic particles that nearly conform to the surface, removing large asperities and creating microasperities compared to hand-buffed surfaces. The process enables smoothing the surface on the nanometer scale with critical control of surface lay (e.g., crosshatch angle), altering the contact angle of water by a combination of kinematic behavior of magnetic particles over the freeform condyle surface.     

Reverse engineering of human bones by using method of anatomical features

In this paper a new method of anatomical features (MAF) for the creation of 3D geometrical models of human bones (polygonal, surface and solid) and parametric point models (predictive bone models) is presented. The main benefit of the MAF application comes from its capability to create a complete geometrical model even if a part of bone is missing or only a single X-ray image is available. The testing of MAF for twenty femur samples and ten tibia samples have shown that the created bone and bone region models are characterized by a good level of anatomical and morphometric accuracy, that is, they are within the required limits defined by orthopaedic surgeons.     

等温多向锻造AZ61镁合金的组织演化与力学性能

研究AZ61镁合金在等温锻造过程中的显微组织及力学性能变化,讨论晶粒细化机理及显微组织与力学性能的关系。结果表明：合金的平均晶粒尺寸随着多向锻造道次的增加而减小,在初始的1、2道次变形过程中,晶粒急剧细化,随着变形道次的增加,晶粒细化能力减弱,经过6道次变形后,晶粒尺寸由初始的148gm细化到14μm。晶粒细化主要是由于合金在锻造过程中发生了连续动态再结晶。随着变形道次的增加,合金的抗拉强度、屈服强度和伸长率逐渐增加。