PVA基粘弹性磁性磨具的实验研究及加工参数优化

Experimental Study on PVA Based Viscoelastic, Magnetic and Abrasive Finishing and Optimization of Machining Parameters

目的检验新研制的PVA基粘弹性磁性磨具的表面光整加工性能,掌握配比参数、加工条件等因素对加工效果的影响规律,并对加工参数进行优化以达到最佳加工效果。方法以6061铝合金管外圆表面为光整加工实验对象,通过先导实验首先确定出影响加工效果的主要因素及其参数范围,而后基于响应曲面法实验,对主轴转速、两相质量比、磨粒尺寸及加工时长等因素与工件表面粗糙度下降率(%?Ra)之间的关系进行了探究分析。结果最后通过对实验结果进行方差分析,建立了PVA基粘弹性磁性磨具加工铝合金管外表面的%?Ra预测模型,并对影响参数进行了优化设计,得到在最佳实验条件下(加工时间46 min、两相质量比1.45、主轴转速635r/min、磨粒尺寸65目),工件表面粗糙度下降率为92.5%,最低表面粗糙度为59 nm,显著改善了加工效果。结论作为一种新型光整加工介质PVA基粘弹性磁性磨具,其具有良好的自适应性及流动性,能达到较好的光整加工效果。影响%?Ra的单因素显著性从强到弱依次为:加工时长、主轴转速、磨粒尺寸、两相质量比。交互作用显著的因子为两相质量比+主轴转速、加工时长+主轴转速、两相质量比+磨粒尺寸。在主轴转速、加工时长取高水平,两相质量比取中等水平,磨粒尺寸取低或高水平时,能得到较好的表面加工效果。

The work aims to test the surface finishing performance of the newly developed PVA-based viscoelastic,magnetic and abrasive tool,master the influence laws of the ratio parameters and processing conditions on the processing effect,and optimize the processing parameters to achieve the best processing effect.The main factors affecting the machining effect and the parameters range were determined by the pilot experiment with the outer surface of 6061 aluminum alloy tube as the experimental object.Then,based on the response surface methodology(RSM),the relationship among the spindle speed,the mass ratio of two phases,the size of abrasive grains and the processing time and the reduction rate in surface roughness(%ΔRa)was explored and analyzed.Finally,the%ΔRa prediction model of PVA-based viscoelastic,magnetic and abrasive tool for aluminum alloy tube surface was established by variance analysis of experimental results,and the influence parameters were optimized.Under the optimum experimental conditions(processing time of 46 min,two-phase mass ratio of 1.45,spindle speed of 635 r/min and abrasive size of 65 mesh),the reduction rate of surface roughness of the workpiece reached 92.5%,and the best surface finish reached 59 nm,thus significantly improving the machining effects.As a new finishing medium,PVA-based viscoelastic,magnetic and abrasive tools have good adaptability and fluidity,and can achieve good finishing effect.The significant single factor affecting%ΔRa from strong to weak is the processing time,spindle speed,abrasive particle size and two-phase mass ratio.The significant interactive factors are two-phase mass ratio+spindle speed,processing time+spindle speed and two-phase mass ratio+abrasive particle size.When the spindle speed and machining time are high,the mass ratio of two phases is middle and the abrasive grain size is low or high,a better surface finishing effect can be obtained.