Preparation And Grinding Performance Of An Engineered Internal-Cooling Grooved Grinding Wheel

Grinding plays an irreplaceable position in the manufacture of key components of nickel-based alloys.To reduce the material bonding,peeling,work hardening and tensile residual stress of nickel-based alloys on the machined surface during the grinding process due to excessive grinding heat,internal-cooling and intermittent grinding methods were used to improve the utilization rate of grinding fluid and enhance the heat transfer effect.Meanwhile,several kinds of patterned abrasives were prepared to improve the problem of abrasive clogging on the surface of traditional grinding wheel and poor heat transfer effect.Combining the advantages of internal-cooling processing technology and ordered abrasive technology,an internal-cooling grinding wheel with ordered abrasive was designed and prepared through the simulation of the flow field inside the grinding wheel and the grinding zone.Grinding experiments of nickel-base superalloy GH4169 by internal-cooling grinding wheel were carried out,and the influence of grinding parameters and abrasive patterns on grinding temperature and surface quality was analyzed.The main research contents are as follows:(1)Based on the working principle of the internal-cooling grinding wheel,a central liquid-injection internal-cooling grinding wheel was designed.The internal flow field model was established to simulate the flow field inside the grinding wheel.According to the results of the flow distribution and the outlet velocity,the structural optimization of the grinding wheel was performed.The finite element method was used to analyze the strength and stiffness of the grinding wheel to ensure the feasibility of the wheel structure.The realization of different abrasive patterns was explored.Based on the designed structure of the internal-cooling channel,five abrasive patterns(type A-E)were designed and prepared by vacuum brazing technology.The abrasives were tested and image processed,and the density of the abrasive grains of different patterns was extracted as the modeling parameters of the subsequent flow field analysis.(2)Based on the test results of the abrasive,the flow field model of the grinding zone was established.The computational fluid dynamics method was used to analyze the flow field of the grinding zone under different outlet position of the cooling channel,grinding parameters and abrasive patterns.The velocity vector distribution and the effective flow rate of each grinding zone were respectively extracted as effective indexes to qualitatively and quantitatively analyze the effect of the channel outlet position,the grinding parameters and the abrasive patterns on the utilization rate of the coolant.Thus the outlet position of the cooling channel and the abrasive pattern were optimized.(3)The 3D printing model was prepared according to the actual size of the grinding wheel,and it was connected to the machine tool for trial operation and the coolant was injected to verify the stability and sealing of the grinding wheel.To verify the correctness of the flow field analysis of the grinding zone,the internal-cooling grinding wheel was manufactured and the grinding test platform was built.A single factor test scheme was designed,and experiments of grinding nickel-base superalloy GH4169 were conducted to study the effects of rotating speed of the grinding wheel,coolant pressure and abrasive pattern on grinding temperature and machined surface quality.