Research On Precision Turning Technology Of Grey Cast Iron By PCBN

Manufacturing has been a key factor in global economic growth.Grey cast iron is widely used in various fields with its good casting performance,wear resistance,vibration damping and cutting performance,especially in automotive industry.But domestic gray iron processing efficiency is much lower than abroad.The application of superhard aterials such as PCBN in foreign countries is far more than that in China.This causes the market competitiveness of domestic gray iron processing enterprises has declined sharply.In order to solve this problem,it is necessary to carry out targeted research on tool materials and processing conditions.This paper is a study of precision turning technology of gray cast iron by PCBN.The main objects of this study are cutting force,the change of cutting temperature,the influence factors of the machined surface roughness and the tool wear.In this paper,a series of cutting experiments have been carried out on the precision turning of gray cast iron by using different cutting parameters,tool geometry parameters and PCBN tool model.The experimental results show that the radial force and the main cutting force are larger cutting forces,and the axial force is smaller.The back engagement of the cutting edge has the greatest influence on the cutting force of the three elements.The cutting force of rough machining is about three times that of finishing.When the cutting speed is lower than 300m/min,the cutting force decreases with the increase of the cutting speed,and the PCBN tool is suitable for high speed cutting.The influence of the radius of arc and chamfering angle on cutting temperature is that the cutting temperature increases linearly with the increase of both.Through the detailed analysis of the experimental data of surface roughness and tool wear,the change regulation is obtained.When the cutting speed is over 400m/min,the excellent performance of PCBN tool can be realized.Surface roughness is better than low speed.The choice of the tip arc angle of 0.8mm can not only get the ideal roughness,but also prolong the life of the tool.Chamfering width and negative chamfering Angle will aggravate the wear of the tool,and it will reduce the surface roughness.PCBN cutting tools are more suitable for the use of dry cutting cooling conditions.A high content of CBN and small particles of PCBN cutting tools can get a better surface roughness.When PCBN tools cut gray cast iron,it is easy to break the edge.Based on the experimental results and the patterns,select the most suitable processing conditions for a single processing instance,to test the results and patterns of the experiment,and conclude the idea of using a PCBN cutter in the actual process.It can replace the original turnning and the grinding process to get better machining accuracy.The processing efficiency is more than 3 times that of the original.It reflects the practical significance and value of the research.