基于响应面法的钛合金Halbach阵列增强磁流变抛光工艺参数优化OA北大核心CSTPCD

It is a titanium alloy magnetorheological polishing method that uses a Halbach magnetic field array to increase the magnetic field.By changing the magnetic array to a circular Halbach magnetic field and rotating the liquid-carrier disk and magnetic array in reverse,the polishing tool can have stronger resilience and self sharpening without changing the material or number of magnets,thereby improving the magnetorheological polishing efficiency of titanium alloy.The work aims to study the interactive impacts of process factors on Halbach array improved magnetorheological polishing and develop and optimize a mathematical prediction model for shear force and surface roughness by response surface methods. With size TC4 titanium alloy as the polishing specimen,the test specimen was firstly cross-polished with 10000 grit sandpaper to remove the surface oxide layer.The test specimen was then placed in a sealed bag,the workpiece was soaked in anhydrous ethanol and sealed and subject to 30 minutes of ultrasonic cleaning to eliminate surface contaminants.During the experiment,an appropriate volume of magnetorheological fluid was introduced to the outside of the liquid-carrier disk.The magnetorheological fluid adsorbed on the liquid-carrier disk in the presence of a magnetic field to produce a flexible polishing tool.The liquid-carrier disk rotated at nc to force the abrasive particles on the surface of the polishing tool to polish the workpiece.To generate a dynamic magnetic field,the Halbach array magnet rotated at a speed of nm concentric and opposite to the liquid-carrier disk.The shear force was measured with a force measuring device(Kistler 9139AA)and the effect of process parameters on polishing force was examined.After the experiment,the workpiece was soaked in deionized water,sealed in a bag,and subject to ultrasonic cleaning to eliminate any remaining pollutants on the surface.The polishing center with the best polishing quality was selected as the sampling point,the surface morphology of the test specimen sampling point was observed with a laser confocal microscope(OLYMPUS OLS4100),the surface roughness was measured by a roughness meter(Xi'an Wilson DM120),the average of three data was staken as the sampling data,and the impact of process parameters on surface quality and surface roughness was analyzed. The response surface method was utilized successfully to optimize three process parameters:the rotational speed of the liquid-carrier disk,the rotational speed of the magnet,and the machining spacing.A fitting equation mathematical prediction model for shear force and surface roughness was constructed.In response surface interaction analysis,the order of effect of process parameters on shear force was:the machining spacing,the rotational speed of the magnet speed and the rotational speed of the liquid-carrier disk.The order of effect on surface roughness was:the rotational speed of the liquid-carrier disk,the rotational speed of the magnet and the machining spacing.The combination of process parameters in the chosen range was chosen based on various needs.When material needs to be removed fast,the following set of process parameters tended to cause the shear force to go to its maximum:the rotational speed of the liquid-carrier disk was 227 r/min,the rotational speed of the magnet was 64 r/min,and the machining spacing was 0.1 mm,and a clean surface with a surface roughness Sa of 34.911 nm was attained after 20 min of polishing and the shear force used to polish titanium alloy was 0.812 N.When the best possible surface quality was needed,the following set of process parameters tended to cause the surface roughness to go to its minimum:the rotational speed of the liquid-carrier disk was 300 r/min,the rotational speed of the magnet was 150 r/min,and the machining spacing was 0.1 mm,and a clean surface with a surface roughness Sa of 26.723 nm was attained after 20 min of polishing and the shear force used to polish titanium alloy was 0.796 N. Halbach array-enhanced magnetorheological polishing can provide a smooth titanium alloy surface with good surface quality under the right process parameters.The primary factors enhancing the surface quality and polishing effectiveness of titanium alloy magnetorheological polishing are the Halbach array and the polishing tool.The magnetic induction lines of the Halbach array exhibit spatial variability and a high magnetic field intensity.More postural changes in the magnetic chain in the magnetorheological fluid can result from the dynamic magnetic field produced by the polishing device's liquid-carrier disk and reverse-rotating magnetic field array.