Study on Mechanism of Roundness Improvement by the Internal Magnetic Abrasive Finishing Process Using Magnetic Machining Tool

Jiangnan Liu,Yanhua Zou

doi:10.3390/machines10020112

Abstract

An internal magnetic abrasive finishing process using a magnetic machining tool was proposed for finishing the internal surface of the thick tubes. It has been proved that this process is effective for finishing thick tubes, and it can improve the roundness while improving the roughness. However, the mechanism of improving the roundness is not clear, so it is necessary to study it theoretically. In this research, firstly, the roundness curve expression was derived using the principle of roundness measurement by the assumed center method, and the expression of roundness curve expanded by Fourier series was obtained. The influencing factors of roundness improvement were then analyzed. Secondly, the experiments were carried out on SUS304 stainless steel tubes. By confirming the mechanism analysis results and the experimental results, it was concluded that the internal magnetic abrasive finishing process using the magnetic machining tool was effective for improving the roundness of the thick tubes whose thickness is from 10 mm to 30 mm. As the thickness of the tube increased, the improvement in roundness decreased.

Highlights

A high-precision internal surface of clean gas cylinders and gas piping systems used in the semiconductor manufacturing industry is required to prevent the adhesion of contaminants
Shinmura et al developed an internal finishing process based on the application of magnetic abrasive machining, and it was confirmed that this process is applicable to the internal finishing of the bottom of a clean gas bomb with a narrow opening which is hard to finish by the conventional finishing process [5]
The roundness curve expression was derived using the principle of roundness measurement by the assumed center method, and the expression of roundness curve expanded by the Fourier series was obtained

Summary

Introduction

A high-precision internal surface of clean gas cylinders and gas piping systems used in the semiconductor manufacturing industry is required to prevent the adhesion of contaminants. The magnetic field-assisted finishing process has been proposed for machining highly finished internal surfaces that are difficult to process with ordinary tools and labor [1,2,3,4]. Utilizing the penetrability of magnetic field lines, the application of magnetic force has great advantages for the precision machining of internal surfaces. There have been many studies on the internal surface finishing process using the finishing force generated by magnetic field. Shinmura et al developed an internal finishing process based on the application of magnetic abrasive machining, and it was confirmed that this process is applicable to the internal finishing of the bottom of a clean gas bomb with a narrow opening which is hard to finish by the conventional finishing process [5].

Methods

Results

Discussion

Conclusion