| GH4169 is widely used in aerospace industry for its excellent high temperature performance.However,It has bad cutting performance,it is a typical kind of hard to cut material.At the same time,for the complex of aerospace parts,the intermittent turning is often used in the aerospace manufacturing industry.The cutting tool bears repeated mechanical and heat shock during the intermittent turning,therefore,the tool life reduce sharply,cutting quality and cutting efficiency often hard to guarantee.So improve the tool life and work piece surface quality for the intermittent turning of GH4169 play an important role for high efficiency machining in aerospace industry.This paper research about the intermittent turning of GH4169,investigate about the optimization of chamfer parameter of cutting tool and cutting parameter.The main contents of this paper is organized as follows:The cutting force,tool life and tool wear mechanism during intermittent turning and continuous cutting of GH4169 are investigated.Analyze the intermittent cutting mechanism of GH4169.Effective impact force has a great influence on tool life during intermittent turning the wear mechanism of GH4169 intermittent turning tool is mainly edge breakage,bond wear and abrasive wear.Stress shock and thermal shock when cut in and cut out are the main factors of tool failure.The influence of negative chamfer structure on tool life in intermittent turning of GH4169 is studied by single factor experiment.It is found that tool life increased at first and then decreased with the increasing of negative chamfer angle and width.To improve the tool life,the optimized parameters of negative chamfer is obtained.Based on the distribution of effective impact force and cutting stress,different parameters of negative chamfer relation with tool performance is analyzed.It is found that the impact of cut-in and cut-out of the tool decreased when negative chamfer parameter increase properly and it could improve the tool life.However,excessive angle and width of negative chamfer increase the cutting temperature,increase the probability of bonding and oxidation wear,and reduce the tool life.The effect of cutting parameter on tool life and failure form of tool during intermittent turning GH4169 are studied.It is found tool life decreased with increasing of cutting parameter.Optimized the cutting parameter aiming at maximum tool life.The variation of stress field and temperature field distribution of cutting tool under different cutting parameters is analyzed.With the increase of cutting parameters,the impact stress and the cutting temperature increased.The effect of chamfer parameter and cutting parameter on machined surface roughness for intermittent turning GH4169 was obtained by orthogonal and single factor experiment.A surface roughness prediction model is established,optimized the cutting parameter and chamfer parameter for better surface roughness.This paper focused on the optimization of chamfer parameter of cutting tool.It could provide technical and theoretical support for interrupted turning of nickel base super-alloy GH4169. |
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