Study On Turning Performance Of Coated Cutting Tools Based On Fractal Theory

Coated tools have high hardness, wear resistance, applicability and excellent thermal stability and other characteristics, so they are widely used in metal-cutting range. Dry cutting is a kind of effective processing method, which can cut without cutting fluid, save resources, reduce the pollution of the environment, realize the green manufacturing. Coated cutting tools are most suitable for this machining method. Therefore, studying on the cutting performance of coated tools has important theoretical and practical significance.Since the1980s, fractal theory has been generally used in the processing and analyze of the natural phenomena with complex detail characteristics. It provides an effective method to solve complex nonlinear problems according to self-similarity principle. Cutting force in the cutting process directly affects the cutting heat generation, further affecting the service life of the tool and the surface quality of the workpiece, etc. Found in the cutting experiment, the change of cutting force signal is non-steady state. The article studied the cutting performance of tool mainly from three aspects: the cutting force, cutting temperature and tool stress in cutting process. The main tasks which have been done are as follows.Firstly, combined with the actual performance demand of dry cutting tool, the coated tool material selection was investigated, and the development of coating technology was discussed. Reasonable choose coating tool and workpiece material to build the cutting experiment platform.Secondly, based on the study of fractal theory and experimental, the fractal dimension D was extracted from the dynamic cutting force component, the eigenvalue cutting force ration R was extracted from the static cutting force component. As the cutting process to study the fractal dimension D and the cutting force ration R changes with the cutting time, and the influence of different cutting parameters on average cutting force and its dynamic component fractal dimension. And by using scanning electron microscope (SEM) and energy dispersive spectrum analyzer (EDX) after cutting tool wear mechanism was analyzed.Thirdly, according to the theory of the finite element analysis of machining, on the basis of tool and workpiece geometry model, material model and friction model, this article used the finite element simulation software DEFORM to simulation the turning performance of more coated tools (TiCN-Al2O3) and single coated tools (TiCN), comparative analysis on the cutting process, the influence of cutting parameters on average cutting force and its simulation signal fractal dimension, the distribution of tool stress and cutting temperature.This paper studied the turning performance of coated tools through turning experiment and finite element simulation combining method, which is based on fractal theory. The analysis results have great significance for the reasonable selection of coated tools and studying its performance in the actual production.