金属的生物去除加工法

生物去除法是利用微生物代谢过程中一些复杂的生物化学反应达到去除多余材料，加工出其他微细加工方法不能加工的微小零件。阐述了尝试用一种铁氧化细菌——氧化亚铁硫杆菌作为生物氧化剂，刻蚀以铜及铜合金为材料的基片表面得到精细图形或三维结构的原理和方法。总结了这种新型加工方法的优缺点，在提高加工精度和生物加工机理方面进行了更深入的研究。     

硬脆材料旋转超声加工技术的研究现状及展望

旋转超声加工是一种复合特种加工技术,它复合了传统超声加工和普通磨削加工的材料去除方式,在提高硬脆材料去除效率、减小切削力、提高加工精度和表面完整性等方面具有显著优势。自旋转超声加工技术发明至今,国内外学者开展了大量的有关旋转超声加工装备及工艺的研究工作,并且已在几乎所有主要的硬脆难加工材料中得到实际应用。本研究在简要概述旋转超声加工技术的基本原理和发展过程基础上,总结国内外学者在材料去除机理、工艺特性、加工新形式以及装备研发等几方面的主要研究成果,并对旋转超声加工技术的发展趋势及值得关注的问题进行展望。     

激光加工内腔技术的研究

文章汇集了激光理论、先进制造技术和材料学科的相关知识，把激光与透明材料相互作用机理应用到内腔加工上，并运用了CAD/CAM知识生成激光聚焦点的加工轨迹，利用超声波振动技术去除切屑。     

复杂曲面零件超精密加工方法的研究进展

超精密加工技术是降低工件表面粗糙度、去除损伤层,获得高形状精度、表面精度和表面完整性的终加工手段。复杂曲面零件的广泛应用和精度要求的不断提高,取决于复杂曲面零件的超精密加工技术。概述了复杂曲面零件的超精密成形加工、超精密抛光等加工方法,分析各种典型加工方法和材料去除机理,从加工精度、工具与曲面吻合度、加工效率与成本、环境友好性等方面对几种复杂曲面超精密加工方法进行比较。对复杂曲面零件超精密加工技术的发展趋势进行预测。     

弱电解质溶液EDM/ECM复合加工机理研究

弱电解质溶液中利用电沉积补偿电极损耗的电火花/电化学复合加工技术可以大幅降低电极损耗,对提高微细电火花加工效率具有重要意义。由于该工艺方法是EDM/ECM复合加工领域一个新的研究方向,研究成果很少。为加深对利用电沉积补偿电极损耗的电火花/电化学复合加工技术的认识,基于实验结果,对弱电解质溶液中的电火花/电化学复合加工的材料去除机理、放电通道形成机理及电极损耗机理进行了初步探索,得到了以下结果:电火花放电蚀除和电化学溶解共同将工件材料去除;大量气泡存在于电极间隙使复合加工放电通道的形成异于电火花放电加工;电沉积作用和电火花放电蚀除共同对工具电极损耗产生影响。     

流体磨料光整加工理论与技术的发展

20世纪60年代发明的挤压磨料流技术在机械零件去毛刺、抛光等光整加工领域产生了重要的影响,特别是自20世纪80年代引入我国之后,国内的科研人员进行了大量的理论研究与应用实践,不断涌现出新的以流体磨料为工具的光整加工技术。从流体磨料的材料去除机理、加工参数对性能优化的影响及应用中存在的均匀性问题及辅助控制技术三个方面综述流体磨料加工过程中的流动特性、去除机理及加工仿真等理论成果,总结近50年来传统黏弹性挤压磨料流技术及近年来针对于松散低黏度流体磨料的光整加工新技术,分析流体磨料加工的研究手段与方法,为今后进行深入的流体磨料光整加工研究,探索在诸如航空叶轮和叶盘等高性能复杂曲面零件高质量抛光中的应用提供了借鉴的方向。     

生物骨材料切除理论研究综述

生物骨材料是一种结构复杂的各向异性材料,其切削加工是外科手术中一项基础而关键的操作.骨材料的加工质量直接影响手术治疗效果、人工假体植入稳定性、以及术后康复时间.人体不同部位的骨材料的力学性能存在一定差异,手术器械种类繁多且操作不同,使骨材料的加工方式呈现多样化.在外科手术中,各类器械需要对骨材料进行高精度、高效率、低损伤的加工,其加工机理研究对提高手术器械的使用性能,手术治疗效果和康复效果具有重大意义.因此,从生物骨材料的基础力学与断裂力学等特性出发,阐述了包括钻、铣、磨、锯等机械加工方式以及超声、激光、和水射流等特种能场加工方式对骨材料的切除机理,分析了不同机械加工方式下的切削力与切削温度理论模型,特种能场的切除机理与加工特性,指出骨材料加工的发展现状以及目前存在的一些问题,提出了骨材料加工的主要研究重点.     

超精密加工现状综述

超精密加工是获得高形状精度、表面精度和表面完整性的必要手段.精密光学、机械、电子系统中所用的先进陶瓷或光学玻璃元件通常需要非常高的形状精度和表面精度(如0.1 nm级表面粗糙度)及较小的加工变质层.掌握超精密加工过程中材料去除规律和损伤层特性对提高加工的稳定性与经济性十分重要.对超精密加工中的超精密切削、超精密磨削和超精密研磨抛光技术进行综述,重点介绍各种典型加工方法及其材料去除机理.从加工精度和加工效率角度对上述几类超精密加工方法进行比较,介绍以实现高效精密加工为目的的半固着磨粒加工技术.对超精密加工的发展趋势进行预测.     

旋转超声磨削加工建模与仿真研究

旋转超声磨削加工结合超声加工和磨削加工的技术优势，在难加工零件的精密制造中具有较大应用潜力。根据旋转超声磨削加工机理，建立旋转超声磨削加工中材料去除体积和加工表面粗糙度的数值计算模型。基于MATLAB软件编写旋转超声磨削加工仿真程序，对材料去除体积、加工表面形貌和表面粗糙度进行仿真模拟，并探究不同加工参数对表面粗糙度和材料去除体积的影响规律。仿真结果表明：主轴转速与超声振动频率之比(n/f)对加工表面形貌和去除体积有决定性影响，n/f比值增大能够有效降低表面粗糙度和提升材料去除体积；详细探讨了磨粒直径、振幅等参数对旋转超声磨削加工表面形貌和去除体积的影响规律，并仿真模拟了参数优化前后的加工表面形貌。     

超硬材料加工技术及其发展趋势

介绍超硬材料的应用背景,说明超硬材料加工技术产生与不断获得发展的必然性,继而介绍超硬材料加工常用的两类方法,即机械加工及特种加工,其中重点介绍各种具体加工方法的材料去除机理、加工特点、发展现状以及趋势.     

A study on copper micromachining using microorganisms

Biomachining using microorganisms to remove metal from a workpiece is an alternative technology for machining processes that may have environmental advantages. Studies of the characteristics of micromachining using microorganisms such as Acidithiobacillus ferrooxidans will explore and improve the capabilities of this alternative machining process. The objective of this study is to investigate the surface roughness and the material removal rate characteristics in biomachining of copper for various machining times. We present the biomachining of copper using A. ferrooxidans, including bacterial culturing and workpiece preparation, and a comparison of the surface roughness, visible surface appearance of the workpiece, and material removal rate before and after biomachining process.     

Development of digital lithography masking method with focusing mechanism for fabrication of micro-feature on biomachining process

An alternative method is developed to remove metal from a work piece by combining a digital lithography system with biomachining. The purpose of this system is to obtain extra advantages as compared to conventional micro-fabrication processes currently used in practice. The use of microorganisms as a cutting tool in biomachining can eliminate the use of hazardous chemical materials, and the target surface is not affected by heat as a result of machining. The proposed process has a low material removal rate, but with less energy consumption. The greatest advantage is that the tools used in biomachining can be cultured continuously; i.e., they are renewable. Theoretically, the resolution of biomachining can reach 1 um due to the size of the bacteria. To achieve selective material removal, we combine the biomachining process with a polymer mask generated by a digital lithography (DL) system. In order to minimize errors and noise, the DL system was constructed by choosing robust and commonly available devices for most of the sub-tasks. This construction then can bring projected image onto work piece surface on fully controlled.     

精密球超精密加工技术的研究进展

掌握精密球超精密加工过程中的球面研磨轨迹分布特性以及各工艺参数对加工结果的影响,对提高精密球加工精度与效率十分重要。对精密球超精密加工技术的发展及研磨均匀性的评价进行回顾,并根据精密球超精密加工技术的发展脉络,阐述当前主要精密球超精密加工技术的加工原理及加工实例。从材料去除率、加工精度、批一致性等方面对几种精密球超精密加工技术进行比较,并以提高加工精度及加工效率为目标,对精密球超精密加工技术的发展趋势进行预测。     

高速切削机理的研究现状与思考

高速切削将成为21世纪世界制造业重点发展的高新技术，但其机理研究滞后于应用研究的现状已阻碍了高速切削技术的进一步推广和应用。文中介绍了高速切削机理研究的进展情况，并对下一步主要研究内容和方向提出了建议。     

A review on material removal mechanism in electrochemical discharge machining (ECDM) and possibilities to enhance the material removal rate

The concept of electrochemical discharge machining (ECDM), also known as electrochemical spark machining (ECSM), was presented for the first time in 1968. Since then, this technology remains as research topic and was never explained seriously for industrial applications. The ECDM is a non-traditional machining technology used for machining of electrically non-conducting materials like glass, ceramics, quartz, etc. The literature reveals that the concept of mechanism of material removal in this machining process is not yet understood well. However, phenomena involved in the material removal needs to be investigated well in order to improve the process. In this paper, the concept of mechanism of material removal in ECDM is reviewed till date; scopes for further research have been identified. Possible future efforts to enhance the material removal rate in ECDM are also discussed.     

Effect of machining parameters on the milling process of 2.5D C/SiC ceramic matrix composites

Abstract

The C/SiC ceramic matrix composites are widely used for high-value components in the nuclear, aerospace and aircraft industries. The cutting mechanism of machining C/SiC ceramic matrix composites is one of the most challenging problems in composites application. Therefore, the effects of machining parameters on the machinability of milling 2.5D C/SiC ceramic matrix composites is are investigated in this article. The related milling experiments has been carried out based on the C/SiC ceramic matrix composites fixed in two different machining directions. For two different machining directions, the influences of spindle speed, feed rate and depth of cut on cutting forces and surface roughness are studied, and the chip formation mechanism is discussed further. It can be seen from the experiment results that the measured cutting forces of the machining direction B are greater than those of the in machining direction A under the same machining conditions. The machining parameters, which include spindle speed, feed rate, depth of cut and machining direction, have an important influence on the cutting force and surface roughness. This research provides an important guidance for improving the machining efficiency, controlling and optimizing the machined surface quality of C/SiC ceramic matrix composites in the milling process.     

基于电火花加工机理分析的短电弧加工技术机理初探

短电弧加工技术在对特硬、超强、高韧性等难加工材料的高速加工方面具有突出的优良性能.针对目前短电弧加工技术工作机理还不清楚,技术工艺方法还不够先进等现实问题,通过对电火花与短电弧加工机理的初步探索,为短电弧加工技术的进一步研究提供了有力的支持.     

机械加工强化机理与工艺技术研究进展

综述了两种机械加工强化机理：组织强化和应力强化。根据晶体位错理论分析,组织强化通过改变金属材料微观组织,提高位错密度,使材料流变应力增加,强度提高。介绍了用于解释机械加工位错强化、晶界强化、应变强化、择优取向强化的理论模型及各强化机理在机械加工强化中的作用,分析了应力强化中残余应力的产生原因。以文献研究为基础,总结了机械加工工艺强化原理和工艺设备的发展现状,讨论了机械加工强化机理和强化工艺的对应关系,指出了机械加工强化工艺的发展方向。     

Influence of reinforcement particles on the mechanism of the blasting erosion arc machining of SiC/Al composites

Electrical arc machining has shown its remarkable efficiency in processing difficult-to-cut materials, especially high-temperature alloys and metal-based composites. Despite several studies about the material removal mechanisms of the electrical arc machining of metal alloys, few of these reports relate to the mechanism of machining composites with electrical arcing. Considering that reinforcements such as SiC particles have different thermal and electrical properties with metal alloys, research on the influence of SiC reinforcement on the electrical arc machining process is important and necessary. Based on comparison experiments using 20 and 50 vol.% SiC/Al composites, this research focused on the influence of SiC particles on the machining performance and material removal mechanism of blasting erosion arc machining (BEAM), and further analyzed the influence of reinforcements on composite material removal mechanisms. Analysis revealed that the molten material expelling mechanism is also influenced by the SiC fraction difference. For the BEAM of lower SiC fraction composites, both the SiC particles and the molten aluminum are mainly pumped and ejected by the flushing dielectric. In greater SiC fraction composites, most SiC particles are directly sublimed by heat. In addition, the mechanism of BEAM in the material removal and tool wear of SiC/Al composites was discussed based on heat transfer simulation and observation. Furthermore, the results disclosed that many chemical reactions take place during machining that have an obvious influence on the tool wear rate.     

传动轴误差对扭轮摩擦传动运动性能的影响

针对扭轮摩擦传动机构运动性能受传动轴误差影响的问题,讨论了扭轮摩擦传动机构中传动轴尺寸误差、弹性变形误差和制造形状误差对工作台运动性能的影响。由三扭轮均布结构导程方程式出发,推导出传动轴尺寸误差和传动轴弹性变形误差对机构运动性能没有影响,而传动轴制造形状误差则会在传动轴转动过程中引起工作台位移以2π为周期呈周期性变化的结论,实验结果与分析推导的结论基本相符,为进一步研究扭轮摩擦传动机构特点和提高机构运动性能提供了理论依据。