Research On Magnetic Abrasive Finishing Process Of AlSi10Mg Alloy Curved Surface Formed By Selective Laser Melting

Selective Laser Melting(SLM)technology is an important and typical process type in laser and powder-based additive manufacturing technology.This technology has high precision in forming components,and has a wide range of applications for the manufacture of special complex structures.It provides an integrated solution for the high-efficiency,low-cost,and precise forming and manufacturing of high-performance complex structures.It is used in aerospace,transportation,energy,and modern industry.And other fields have broad application and development prospects.However,due to the technological characteristics of powder layer-by-layer stacking and laser melting in the forming process,the surface quality of the formed part is difficult to meet the performance requirements,so it is particularly important to perform subsequent finishing processing on the surface of the formed part.Magnetic Abrasive Finishing(MAF)technology,as an advanced finishing process,is suitable for the finishing and polishing of various complex curved surfaces due to its flexibility,adaptability and many other advantages.Therefore,this article adopts the magnetic finishing technology,applies its inherent flexible finishing advantage to the finishing of the surface of the surface sample of the SLM formed part,and studies the processing technology and the surface mate rial removal mechanism of the MAF in the surface of the complex surface part formed by the SLM.And surface quality,study its process rules,and apply it to engineering practice.The main research work and innovations of this paper are as follows:1.Research on forming of AlSi10 Mg alloy SLM curved sampleUsing AlSi10 Mg alloy powder as the forming powder material of the curved sample,according to the requirements of the aero-engine blade structure and shape,a threedimensional data model of the AlSi10 Mg alloy curved sample was designed,and the Materialise magics software was used to optimize the forming parameters,and the cube was selected as the sample support The structure,the surface layer and the internal laser melting parameters of the sample are set in layers.The melting parameters with higher hardness and lower roughness are selected as the outer scanning parameters of the sample,and the melting scanning parameters with higher density are used as the sample.With internal forming parameters,the AlSi10 Mg alloy curved sample with high surface hardness and denseness is finally processed by the SLM(?)125HL forming machine.2.Development of AlSi10 Mg alloy SLM curved surface samples with magnetic finishing permanent magnet polesAccording to the size,shape and material characteristics of the AlSi10 Mg alloy SLM forming surface sample,the comsol simulation software is used to design 6 types of magnetic pole three-dimensional simulation models with a slotting angle span of 30°and a variety of geometric slotting shapes.Explore the shape and size parameters of the permanent magnet pole finishing brush suitable for finishing sample materials.Finally,through simulation analysis and theoretical calculation,it is found that the magnetic field strength and magnetic field gradient density increase with the decrease of the angular angle of the remaining geometric surface after slotting,and the concentration is concentrated on the edge.Get the maximum value at the sharp corners.And use the N35 rare earth sintered permanent magnet material to design the 75° trapezoidal slotted flat and ball permanent magnet poles with an aspect ratio of 1:0.5.The magnetic field strength of the designed magnetic pole is compared with the rectangular slotted magnetic pole,and the magnetic field strength of the designed magnetic pole is finally measured to be relatively high,which can provide greater finishing force.3.Research on magnetic finishing of AlSi10 Mg alloy SLM forming surface samplesBased on the NK7136 C CNC milling machine platform,the spindle end tool holder structure is converted into a fixture device that can hold and finish magnetic poles;an indexing fixture rotary table with Ardunio board as the control unit is added to the worktable to construct a curved magnetic finishing test system to achieve 4-axis curved surface finishing test bench with 3 linkage axis + 1 indexing axis.Analyze the removal mechanism of single abrasive particles,and design the rough finishing path path of the magnetic pole finishing with the 75°trapezoidal slotted flat head magnetic pole and the fine finishing path design of the 75°trapezoidal slotted ball magnetic pole finishing the magnetic pole according to the surface shape of the sample..Select the spherical Al2O3 magnetic abrasive with the abrasive phase particle size of W7 prepared by the atomization rapid solidification method,and optimize and analyze the important finishing process parameters such as spindle speed,feed speed,finishing gap and abrasive consumption through 27 sets of orthogonal experiments.According to the range distribution,the specific gravity sequence of the influence of each factor on the sample finishing is obtained.4.Surface quality inspection and analysis of magnetically ground AlSi10 Mg alloy SLM forming samplesThrough the detection and analysis of the surface roughness,surface morphology,Vickers hardness,affinity and hydrophobicity of the sample before and after finishing,it is found that the surface roughness of the sample decreases with the i ncrease of processing time,and the final surface roughness Ra value reaches 0.279 ?m.The surface morphology of the sample is changed from the unpolished ravine to the vertical and horizontal state.After polishing,the surface is flat and smooth.At the same time,it was found that the Vickers hardness of the sample before and after finishing did not change significantly,and it always fluctuated up and down with 126.7HV0.5 as the baseline.The contact angle between the surface of the sample and the deio nized water was increased from ?=1.6° to ?=61.3° before finishing,which changed the hydrophobic properties of the sample from a super-hydrophilic surface to a hydrophilic surface.In this paper,the AlSi10 Mg alloy SLM formed surface is used as the magneti c finishing object.Through the development of permanent abrasive brushes,the construction of the 4-axis finishing test bench,the design of the finishing process and the optimization of the finishing parameters,the surface quality of the AlSi10 Mg alloy SLM formed surface sample is finally obtained.The significant improvement has provided test data and process reference for MAF technology in the finishing of AlSi10 Mg alloy curved parts formed by SLM.