Study On Grinding Performance Of Internal-cooling Grinding Wheel Based On Designing Of Surface Structure And Cavity

As the core tool in grinding process,the grinding performance of grinding wheel directly determines the grinding quality and efficiency of parts.Nickel-based superalloy is widely used as the material of aero-engine core parts.In the final precision grinding of these core parts,there will be burns,hot cracks and residual tensile stress on the machined surface due to the high grinding temperature.Therefore,it is of great significance for the development of aerospace industry to develop new high-efficiency grinding wheel and explore the high-efficiency heat transfer technology in grinding.In this paper,a new type of internal-cooling end grinding wheel was developed by using the method of pressurized internal-cooling and the method of grinding wheel surface structure.And further the grinding experiment of GH4169 alloy were carried out,the influence of wheel speed,micro channel diameter and grinding wheel surface structure on its grinding performance were explored.The main research contents are as follows:(1)The structure of the internal-cooling grinding wheel was designed and optimized.Firstly,according to the working principle of the internal-cooling end grinding wheel and the existing liquid supply problem,the overall structure of the internal-cooling grinding wheel was designed.And the channel outlets were directly and evenly set in the center of the abrasive area of grinding wheel end face;meanwhile,based on the 3D printing technology,the channel structure of the grinding wheel was designed as an independent 3D printing module,and flow channel modules with different micro-channel diameters were designed.Secondly,the computational fluid dynamics method was used to simulate the internal flow field of the grinding wheel,and then,the cavity structure of the grinding wheel was optimized and improved according to the simulation results Finally,the overall structure and size of internal-cooling grinding wheel were determined,and the fluid-structure coupling analysis of grinding wheel was further carried out to check its strength.(2)The surface structure of the grinding wheel was designed based on the surface structuring method of the grinding wheel.According to the phyllotaxis theory,the abrasive cluster with phyllotactic patterns on the grinding wheel surface were designed.Meanwhile,considering the end grinding,the ring-shaped of grinding zone is relatively large,and some waist-shaped grooves were formed in the circumferential direction of the abrasive ring body,which can make the surface structure of the grinding wheel with waist-shaped outlets.(3)The preparation and assembly of the integral parts of the grinding wheel were completed,and the sealing performance of the grinding wheel is further tested to ensure that the design requirements and grinding process requirements can be met.The abrasive rings with different surface structures were prepared by electroplating process,and the surface morphology of the abrasive rings was tested to ensure that the abrasive rings meet the design requirements and grinding process requirements.At the same time,the electroplating height of abrasive cluster was extracted,which can provided modeling parameters for the flow field simulation.(4)The flow field simulation of internal cooling grinding was carried out.Firstly,the internal flow field model of the grinding wheel with different micro-channel diameters was established,and the influence of the micro-channel diameter on the flow characteristics of the coolant in the grinding wheel under different grinding wheel speeds was analyzed,and the jet velocity of grinding fluid at the outlet was extracted.Based on this boundary condition,the flow field simulation of grinding arc zone was carried out,and the influence of the micro-channel diameter and the surface structure of the grinding wheel on the flow characteristics of the grinding fluid in the grinding zone under different grinding wheel speeds was investigated.(5)Aiming at the developed internal cooling grinding wheel,an internal-cooling grinding test platform was built,Under different rotating speeds of the grinding wheel,the experimental study of GH4169 superalloy internal-cooling surface grinding were carried out to study the effects of micro-channel diameter and surface structure of grinding wheel on grinding temperature and machined surface quality.