Process optimization of magnetic grinding TC4 titanium alloy with elastic magnetic pole grinding head

Abstract

Magnetic grinding has the characteristics of conformal machining. However, when a small grinding head is used to magnetically grind a workpiece with a large twist, the difference in the gap between the grinding head at different positions of the workpiece poses a challenge to the magnetic grinding process. In order to improve the surface quality of magnetic grinding and further reduce the influence of the gap difference between the grinding head and the workpiece on the surface roughness, an elastic magnetic pole grinding head with polyurethane elastomer as the magnetic pole carrier was designed, and its magnetic field simulation analysis and verification were carried out. In the experiment, the self-made diamond magnetic abrasive was used to compare the grinding performance of the polyurethane elastic magnetic pole grinding head and the ordinary magnetic pole grinding head under different machining gaps. The influence of the process parameters such as spindle speed, feed rate and abrasive particle size on the surface roughness of the workpiece was studied experimentally. The experimental results show that under the same process parameters, the processing performance of the polyurethane elastic magnetic pole grinding head is better than that of the ordinary magnetic pole grinding head under different machining gaps. Using polyurethane elastic grinding head, when the spindle speed is 800 r/min, the machining gap is 2.0 mm, the feed speed is 5 mm/min, and the abrasive particle size is 62 to 90 μm, the magnetic grinding effect is the best. After 12 minutes of grinding, the surface roughness Ra of TC4 titanium alloy can be reduced from the initial 0.350 μm to 0.039 μm, and the surface roughness improvement rate reaches 89%. The results verify the effect of the elasticity and profiling characteristics of the polyurethane elastic layer on the quality of the machined surface.

Keywords

• magnetic abrasive finishing
• titanium alloy
• microscopic morphology
• surface roughness