The Study Of Lapping Mechanism And Surface Quality On Lapping Of Solid Abrasive

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...