Study On Forming Mechanism Of Surface Morphology Of High-speed Cold Roll-beating

High-speed cold roll-beating is a very representative machining technology which is green, high precise and efficient. The technology has many advantages, including high production efficiency, less material consumption and low processing costs. At the same time, it can improve the surface performance and extend the life of products to a large extent. During the forming process of high-speed cold roll-beating, the surface morphology is an important factor that affecting the surface quality of the forming part. So far, the forming mechanism of surface morphology of high-speed cold roll-beating forming has not been mastered by people, as a result, it is difficult that the quality of surface of cold roll-beating forming part achieves the requirement of high accuracy. It is necessary for surface morphology of parts to analyze systematically and research deeply. In this paper, cold roll-beating forming spline is regarded as the object of the study. By means of the theoretical analysis, numerical calculation, simulation analysis, experimental study and others, the changing process of the surface morphology under cold roll-beating forming is analyzed, and the influence regularity of cold roll-beating forming parameters to the evolution of surface roughness is revealed.In this paper, the surface morphology under high-speed cold roll-beating is studied. The composition of surface morphology of spline is analyzed. The influence of cold roll-beating ways and forming parameters on the surface roughness is explored. The forming mechanism of defects, such as surface microcracks, gills defect and others, is revealed. The experiment of surface morphology of cold roll-beating forming is conducted, the surface roughness is extracted, and the surface roughness of different forming parameters is studied. The mathematical model of surface morphology of cold roll-beating forming part is established. And the simulation analysis of surface roughness with condition of cold roll-beating forming is conducted. The surface morphology of high-speed cold roll-beating forming spline is compared to the milling spline’s. The influence of metal flowing on the surface roughness is analyzed by the experiment of the scanning electron microscopy. The relation of forming parameters to the surface roughness is analyzed by the response surface methodology, and the prediction model of surface roughness of spline under high-speed cold roll-beating forming is established.Based on the comparative analysis, it shows that the surface roughness of cold roll-beating forming is less than milling’s, and its surface roughness is more consistent with the requirement of high-precision machining. Based on the theoretical analysis, combining simulation and experimental analysis, the more ideal surface morphology can be obtained by adopting the way of pulling out and climb-beating, suitable rotational speed of the roll-beating wheel and lower feed rate. The roughness of the graduated circle is less than the roughness of the addendum and the dedendum of spline under cold roll-beating forming. The optimal-matching criterion of the surface roughness and forming parameters and the empirical prediction model of the surface roughness can efficiently predict the surface roughness of high-speed cold roll-beating forming parts with different rotational speeds and feed rate. Through the above study, the matching plan of roll-beating way and forming parameters can be obtained. And the surface quality of high-speed cold roll-beating forming is improved to a large extent. To the industrial application of cold roll-beating, the results have great guiding significance to obtain products which have desired surface quality.