材料期刊网

目的 解决钛合金机械加工后表面质量差的难题.方法 采用磁力研磨工艺对TC11钛合金进行了表面光整加工.以表面粗糙度为主要评价指标,研究了磁力研磨工艺参数对钛合金表面质量的影响,并对工艺参数进行了优化.采用优化后的工艺参数对钛合金进行了表面光整加工,研究了磁力研磨工艺对钛合金金相组织的影响.结果 当加工间隙为3 mm时,研磨压力适宜,加工后工件表面粗糙度值最小.采用粒径为100目的磨粒使工件表面研磨加工后纹理更细,表面粗糙度值最低.提高主轴转速,工件表面材料去除率增加,当主轴转速为1500 r/min时,加工后工件表面粗糙度值最小.对比工件加工前后的金相组织,加工后试样表面组织晶粒变细,晶界增多,工件表面应力状态由张应力转变为压应力.结论 实验确定了较优的工艺参数组合,即:加工间隙为3 mm,磨粒粒径为100目,主轴转速为1500 r/min.采用永磁场磁力研磨工艺,能够大幅降低TC11钛合金表面粗糙度,并使钛合金表面组织得到改善.

The work aims to solve the problem of poor quality of machined titanium alloy surface. Surface finishing was conducted to TC11 titanium alloy by virtue of magnetic abrasive process. Effects of process parameters of magnetic abrasive fi-nishing on surface quality of titanium alloy was studied with surface roughness as the main evaluation criteria, and process pa-rameters were optimized on this basis. Surface finishing was conducted by using the optimized process parameters, to study the influence of magnetic abrasive process on microstructure of titanium alloy. When the machining clearance was 3 mm, the grinding pressure was appropriate and the surface roughness of machined workpiece was the minimum; when abrasive grain in 100 meshes was used, the surface texture was fine, surface roughness value was the minimum; provided that the spindle speed and surface material removal rate of the workpiece increased, surface roughness value of the machined workpiece was the min-imum at the spindle speed of 1500 r/min; compared with metallographic structure of the workpiece before machining, the mi-crostructure grain was refined, grain boundaries increased, and the surface tensile stress of workpiece became compressive stress. The experiments have determined the optimal process parameters combination, namely: machining clearance of 3 mm, magnetic abrasive size of 100 meshes and spindle speed of 100 r/min. Permanent magnetic abrasive process can greatly reduce the surface roughness and improve surface microstructure of TC11 titanium alloy.