Research On The Mechanism And Related Fundamental Theory In Micro-grinding

Grinding is recognized as one kind of mechanical processing technology which can achieve the best surface quality and the smallest size tolerance, generally it be used as the last procedure during the processing of working surface. Giving the fact that grinding can obtain a good surface quality, micro-grinding as a new micro processing method appeared which introduce grinding process to the micro processing area, it is an efficient solution to the problems that existing micro machining method usually generate relatively poor surface quality. Micro grinding mainly refers to the material removal process to form the required shape, or finishing on the surface have been processed to meet the technological requirements, micro abrasive diameter less than lmm, usually the abrasive is cylindrical and grain size from a few micrometers to dozens of micrometers.With the help of computer, using finite element analysis software can predict the grinding process and the corresponding parameters, it is an effective method to the auxiliary study, the finite element simulation can play an important role when the experimental conditions is limited. This paper adopts the research method which combined simulation and test together, micro-grinding was taken as research carrier to discusses the micro abrasive preparation technology, micro-grinding force and thermal characteristics, grinding surface quality, micro abrasive wear and other aspects, the specific contents are as follows:(1) This paper adopts the different technological process for the preparation of micro abrasive, analysis the size characteristics, surface morphology and particle distribution of the micro abrasive. Theoretically discusses the processing of micro scale grinding mechanism, studies influence of the cutting path, chip morphology, maximum deformation chip thickness and elastic recovery of workpiece on the machining process. On the other hand, statics analysis was carried out on the micro abrasive to guarantee the micro abrasive tool clamping stability.(2) According to the theory of traditional grinding force model, micro-grinding force model of single abrasive grain is deduced as well as the empirical formula of grinding force, then through the contrast of test and theoretical results, determine the scientific nature and effectiveness of the model. Analysis the influences of workpiece speed, grinding depth and micro abrasive cutting speed on grinding force change rule.(3) Single abrasive grinding heat transfer model is established, by using ABAQUS software to analysis micro-grinding temperature, the influence rule of different grinding parameters on the micro-grinding temperature was got. Through the experiments, measure the micro-grinding surface temperature and temperature of different depth below the surface of position, then find out the change rule of temperature distribution along the surface and the vertical direction of surface.(4) To establish a micro-grinding surface roughness model, the effects of different grinding factors on the workpiece surface roughness and 3D surface topography through the micro-grinding experiment of hard and brittle materials are studied. Through the analysis of machining surface roughness variation degree and surface morphology, find out the main factors affecting the quality of processing. By means of micro-grinding test of metal material to get the rule that the surface roughness increases with the grinding parameters. The experimental results validate the proposed mathematical model.(5) This paper analyzed the wear mechanism of electroplated diamond micro abrasive, aiming at the composite process of micro-grinding area and main characteristics of micro abrasive wear to model the geometry and mathematical model. By considering the minimum chip thickness and size effect and other factors, then the mathematical model of micro abrasive wear is established. The micro-grinding tests of different grinding parameters are carried out on the sodium calcium glass materials. The change laws of the worn micro-grinding tool are proposed by analyzing the diameter of grinding head, the proportion in the total abrasives of worn grits and crushed grits, and the surface roughness of the workpiece.At last, the conclusions and suggestions were given using the experimental and numerical results.