Key Technology And Process Study On Preparation Of CBN/Fe-based Spherical Composite Magnetic Abrasive By Gas Atomization

With the rapid development of high-end fields such as aerospace,the surface quality requirements for some difficult-to-machine materials are getting higher and higher.As one of the finishing techniques,magnetic grinding can improve the surface quality of the workpiece.However,most of the current MAP are mainly abrasives of ordinary hardness such as Al₂O₃ and SiC,which can only improve the surface properties of some common materials,and it is difficult to meet the processing requirements of some difficult materials required for high-end fields.In this paper,through the improvement of the atomizing nozzle,the CBN/Fe-based spherical composite MAP was successfully prepared by the two-stage atomization system.After the magnetic grinding of Inconel718 nickel-base superalloy,it was found that the MAP had good grinding performance and reached the expected test effect.The specific research contents are as follows:1.Research on preparation system and preparation process of CBN/Fe-based MAPDesign and research on the atomization system for preparing CBN/Fe-based MAP by analyzing the principle and process of metal powder preparation by gas atomization.Through the research on ceramic/metal composite theory,the composite process of CBN and Fe-based alloy is analyzed,and the preparation process parameters and preparation route are designed according to the composite process theory of the two.2.Research on key technology of CBN/Fe-based Spherical Composite MAP preparationFirstly,the design and optimization of the atomizing nozzle are required for the preparation of CBN/Fe-based MAP,and the main nozzle optimization parameters are determined.Then,the gas flow field simulation analysis is performed on the two-stage atomization system,and the optimal two-stage atomization gas pressure is determined according to the ideal gas atomization simulation result and the actual atomization test analysis.In the process of preparing CBN/Fe-based MAP,the first MAP preparation test is first carried out using a single-stage atomizing nozzle.According to the results of the first test,CBN/Fe-based MAP that meets the requirements is prepared using the improved two-stage atomizing nozzle.3.Experimental study on grinding performance of CBN/Fe-based MAPThe main factors affecting the abrasive performance of MAP were analyzed,and the magnetic grinding orthogonal test was designed based on these main influencing factors.Through the analysis of the orthogonal test results,the primary and secondary relationships of the factors affecting the effects are determined.Through the observation of the two-dimensional and three-dimensional morphology of the surface of Inconel718 alloy workpiece before and after grinding by CBN/Fe-based MAP,and the analysis and research on the surface roughness value and material removal amount of the workpiece,to judge whether the grinding performance of CBN/Fe-based MAP is good or bad,to determine whether it can meet the surface quality requirements of some difficult materials.