Magnetic Effect on Abrasive Wear of Ferromagnetic Materials and the Application

作者曾报道，即使极弱磁场的存在也能显著降低铁磁材料之间的粘着磨损。认为磨粒磨损的减少是由磁场的二次效应引起的，而由于没有磨损颗粒，磁化对磨粒磨损的影响是主要的。进而推测，如果磁场能使物料的硬度变软，则有助于提高磨削效率。本研究的目的是明确磁对磨料磨损的影响，并为将这种影响应用于磨削积累基础数据。首先，设计并制作了带磁线圈的无止回带磨粒磨损试验装置，并制作了磁化变频器。实验明确地表明，在较大的磁化强度和较高的频率下，磁效应更加明显。认为磁效应是由于振动磁畴壁与位错之间的磁弹性相互作用引起的可动位错密度的增加，以及DELTAE效应对材料的软化。这些解释被材料在交变磁场中的硬度软化所证实。此外，为了在高摩擦速度下进行测试，还制作了磁场磨削装置。结果表明，磁效应随磨速的增加而减小，当磨速为150m/min时，磁效应减小幅度小于1%。这种速度依赖性可以解释为磁畴壁的移动速度不是很高。虽然，当磁效应在摩擦速度下达到几个百分点时，磁效应的可用性还需要进一步的研究。

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.