Magnetic Effect on Abrasive Wear of Ferromagnetic Materials and the Application

1994 Fiscal Year Final Research Report Summary

• Project/Area Number: 05650135
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: 設計工学・機械要素・トライボロジー
• Research Institution: Akita University
• Principal Investigator: KUMAGAI Kazuo Akita University・Mining College Professor, 鉱山学部, 教授 (10005225)
• Project Period (FY): 1993 – 1994
• Keywords: Ferromagnetic Material / Magnetic Effect / Abrasive Wear / Grinding

Research Abstract

It has been reported by the author that the adhesive wear between ferro-magnetic materials was remarkably reduced by the existence of even very weak magnetic field.
It was considered that the wear reduction was caused by the secodary effect of magnetic field, and that the primary effect of magnetization will appear on the abrasive wear, because of the absence of the wear particles.
Then the author conjectured that the magnetic field will help to progress in the grinding efficiency, if the magnetic field make the hardness of material for soften.
The purpose of this research is to clear the magnetic effect on the abrasive wear, and to accumlate the foundamental data to apply this effect on the grinding.
First, the author designed and composed the abrasive wear-test-apparatus with a endless-belt-abrasion and the magnetic coil, and made the frequency converter for magnetization.
It has been definitely shown by the experiments that the magnetic effect becomes more conspicuous in case of greater magnitude of magnetization and when heigher frequency is used.
The magnetic effect was considered to be attributed to the increase of the movable dislocation density which is caused by the magnetoelastic interaction between the vibrating magnetic domain wall and dislocation, and attributed to the softening of a material by DELTAE effect. These interpretation was proved by a softening of hardness of material in the alternating magnetic field.
Moreover, the grinding apparatus in the magnetic field was made in order to test in the high rubbing velocity. It became clear that the magnetic effect decreases as the grinding speed increases, and the effect goes downless than 1% at the 150m/min. This velocity dependence will be explained as the moving velocity of magnetic domain wall is not so high.
Although, as the magnetic effect becomes to a few % at the law rubbing velocity, the available use of magnetic effect requires further examination.