【作者】 田春林；

【导师】 姜会林； 杨建东；

【作者基本信息】 长春理工大学 ， 机械制造及其自动化， 2005， 博士

【摘要】 由于精密和超精密加工技术在国防、航空、航天等领域的重要作用，受到了人们的广泛关注，已成为衡量一个国家制造业技术水平的标志。研磨加工作为精密、超精密加工中的一种重要加工方法，也日益受到了重视，国内外的专家学者发明了许多新的研磨加工方法，如电解研磨、ELID在线修整研磨、磁力研磨、无磨料的冰盘研磨、固着磨料研磨等，这些方法都在不同程度上提高了研磨加工的精度和加工质量。尤其是固着磨料高速研磨，不仅提高了加工精度，而且极大地提高了加工效率，降低了加工成本。但由于影响研磨加工过程的因素多，工件表面形成过程非常复杂，因此，尽管人们已经用研磨加工获得了较高的面形精度及较低的表面粗糙度值，但人们对研磨的加工机理研究的还不够深入。随着研磨技术的应用日益广泛，人们也越来越关注其加工后的表面微观形貌、表面残余应力和加工硬化程度等表面质量因素。因此对固着磨料加工机理进行深入研究，以拓展其应用范围具有重要的意义。本文正是在这一背景下进行的。主要进行了以下几个方面的研究： 本文对固着磨料研磨机理及已加工表面形成过程进行了研究。传统散粒磨料慢速研磨由于磨料在磨具上是随机分布的，所以其与工件之间的相互作用关系是不确定的，因此很难对其进行分析。固着磨料研磨中，磨料与工件之间的相互作用关系具有一定的确定性，本文就是在此基础上，首先分析了研磨过程中磨粒的受力情况，并对磨粒的切削刃做了球冠形假设，以此为依据建立了固着磨料高速研磨的力学模型。 对固着磨料高速研磨工件已加工表面理论粗糙度进行了探讨，并对工件已加工表面粗糙度、微观形貌与研磨加工中各工艺参数之间的关系进行了研究。研究表明，不同的研磨参数对这两项指标有一定的影响。其中磨料粒度对工件表面粗糙度影响较大，研磨速度对其影响较小。实验还表明研磨加工后，工件表面都产生塑性变形，即使是像陶瓷、硬质合金等硬脆性材料，其表面也存在一定的塑性变形。本文对塑性变形产生的原因进行了分析，塑性变形是晶体内位错运动的结果，对于硬脆性材料，晶体内可移动的位错极少，当受到外力作用时，在产生微塑性的同时伴随晶粒的破碎细化。而晶粒细化的结果又会促进塑性变形，进而形成了已加工表面的塑性变形层。 对工件表面残余应力产生的原因及其变化规律进行了研究。首先从理论上分析了研磨加工过程中残余应力产生的原因，探讨了磨料粒度、研磨压力和研磨速度对工件已加工表面残余应力的影响，通过研究发现，在固着磨料研磨加工中，工件已加工表面残余应力一般是压应力，而且随着磨料粒度、研磨压力、研磨速度的增大，工件表面残余应力增加。 对固着磨料研磨表面加工硬化现象进行了研究。根据位错理论对研磨中产生加工硬化的原因进行了分析，本文认为研磨后，工件表面的位错增殖及交割是导致加更多还原

【Abstract】 With its increasing important role in fields of civil-defense, aviation and astronautics, precision and ultra-precision machining wins extensive care, and is one of tokens to mark manufacturing technology level of a country. Being a key machining method among which, lapping is paid more stress on. Experts from home and abroad have invented various lapping processes, such as electrochemical lapping, ELID online dressing lapping, magnetic lapping, ice dish lapping without abrasives and solid abrasive lapping etc., and all these lapping processes improve precision and quality of lapping to a certain degree, especially high-speed lapping with solid abrasive improved machining precision, increased machining efficiency sharply, further more reduced machining cost. But, there exist many factors affecting lapping process and parts’ surface forming is very complicated, experts have been not engaged in studying of lapping machining mechanism, although fine roughness of surface and profile precision has been achieved. With the extensive application of lapping technology, people will further care about machmed parts’ surface micro topography, surface residual stress and machining hardening etc. surface quality factors. Hence it is crucial to deeply study machining mechanism of solid abrasive in a bid to expend the application range. This is the very background of the paper. This paper relates to the following studies:This paper studied solid abrasive lapping mechanism and surface forming process of machined parts. As regards abrasives of traditional lapping randomly scatter on the tooling, the interaction between abrasive and the machined part is uncertain, so it is not easy to analyze. But for solid abrasive lapping, there exists a certain interaction between abrasive and the machined parts. On this basis, this paper firstly makes mechanics analysis of lapping grains in the process of lapping, and assumes the grain is in the form of spherical surface, and set up mechanics model of solid abrasives lapping on this assumption, further more analyzed forces.This paper made a study of theoretical roughness of surface on machined surface by high-speed lapping with solid abrasive, and of the relationship between machined surface roughness, micro-topography and parameters of lapping. The results show that, different lapping parameters have a certain influence to these two factors, among which, grain size has a considerable influence to machined surface roughness, and lapping speed has a smaller influence. And experiment indicate that, machined parts will occur plastic deformation after lapping, even surface of brittle materials such as ceramics and carbide will deform to a certain degree. The paper analyzes the reasons of plastic deformation, the movement of the dislocation in crystal is the important one, for brittle materials the movable proliferations is few, it will occur plastic deformation while crystal particle fragmentation and refining under external forces. And crystal particle refining will result in further plastic deformation, so machined surface will form a plastic deformation layer.This paper also made a study of reasons of residual stress on machined surfaces and更多还原