基于混合粒径的TC4钛合金低粗糙度磁力研磨研究  

Research on Low Roughness Magnetic Grinding of TC4 Titanium Alloy Based on Mixed Particle Size

作　　者：陈晓明 徐成宇[1] 季冬锋 刘宁 朱永伟 CHEN Xiao-ming;XU Cheng-yu;JI Dong-feng;LIU Ning;ZHU Yong-wei(College of Mechanical&Electrical Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Jiangsu Maritime Institute,Nanjing 211100,China)

机构地区：[1]南京航空航天大学机电学院,南京210016 [2]江苏海事职业技术学院,南京211100

出　　处：《表面技术》2023年第12期112-118,159,共8页Surface Technology

摘　　要：目的获得更低粗糙度的TC4钛合金零件表面。方法采用黏结法制备不同粒径的磁性磨料,依次运用粒径为150~250μm和63~106μm的磁性磨粒以及这两种粒径的混合磨料进行磁力研磨对比实验,分析基于混合粒径的TC4钛合金低粗糙度磁力研磨可行性。基于磁性颗粒动力模型,根据最小能量原理分析了混合粒径磁力链的微结构,并利用体式显微镜对单粒径和混合粒径磁力链进行对比分析。结果单粒径和混合粒径磁力研磨在12 min时钛合金工件表面粗糙度均约为0.11μm,此时单一粒径趋于平衡,而混合粒径磁力研磨的表面粗糙度继续下降,在16 min左右达到最低,为0.084μm,比单一粒径降低了20%,工件表面初始划痕和凹坑得到了更好的去除,加工后表面纹理更为致密。大粒径磁力链颗粒能量最小,约为‒3.6×10^(‒13)J,其次是混合粒径磁力链结构,颗粒能量约为‒2.1×10^(‒13)J,而小粒径磁力链结构颗粒能量约为‒0.45×10^(‒13)J,是大粒径和混合粒径磁力链的5~9倍,这说明小粒径颗粒不易形成单独磁力链。结论混合粒径磁力链中,小粒径颗粒不易形成单独磁力链,而是吸附在大粒径磁力链间隙中,提高了磁力刷的刚性和密度,不同粒径的磨粒同时参与研磨,从而在混合粒径磁力研磨TC4钛合金中能够有效的降低表面粗糙度。To obtain a lower roughness surface of TC4 titanium alloy parts,magnetic abrasives with different particle sizes were prepared by the bonding method in this paper.Abrasives with particle sizes of 150-250μm,63-106μm,and mixed abrasives of both sizes were successively used for magnetic abrasive finishing(MAF)comparison experiments,and the feasibility of low roughness MAF of TC4 titanium alloy based on mixed-size abrasives(MSA)was analyzed.Based on the dynamic model of magnetic abrasives,the microstructure of the magnetic chains in MSA was analyzed by the minimum energy principle,and the magnetic chains of single-size abrasives(SSA)and MSA were compared by the stereomicroscope.Results showed that the surface roughness Ra of the titanium alloy workpiece processed by SSA and MSA was both about 0.11μm at 12 minutes,but it would continue to decrease in the MSA finishing.The lowest roughness Ra in MSA finishing was 0.084μm at 16 minutes,which was 20%lower than that of SSA finishing.The initial scratches and pits on the workpiece surface were better removed and the surface texture was denser after MSA finishing.In the observation experiment,it was found that the magnetic chain formed by the single-size particles had more bifurcations and voids,which were relatively loose,while the bifurcations and voids of the magnetic chain formed by the mixed-size particles were significantly reduced,and the combination was closer with the decrease of the particle size ratio.Besides,the particle energy of the magnetic chain formed by large-size particles was the smallest,which was about‒3.6×10^(‒13)J,and then followed by mixed particle size magnetic chain structure with particle energy of approximately‒2.1×10^(‒13)J.According to the principle of minimum energy,the smaller the energy is,the more stable the structure is.The magnetic chain structure of small-size particles with particle energy of approximately‒0.45×10^(‒13)was hard to form,because the particle energy in the small-size magnetic chain was 5-9 times higher

关 键 词：混合粒径 磁力研磨 表面粗糙度 磁力链 

分 类 号：TG356.28[金属学及工艺—金属压力加工]