Magnetic Effect on Abrasive Wear of Ferromagnetic Materials and the Application

作者曾报道，即使是很弱的磁场也能显著降低铁磁材料之间的粘着磨损。认为这种磨损的减少是由于磁场的二次效应引起的，由于磨粒的不存在，磁化对磨粒磨损将出现主要效应。作者推测，如果磁场使材料的硬度变软，那么磁场将有助于提高磨削效率。本研究的目的是明确磁场对磨粒磨损的影响，并为将这种效应应用于磨削积累基础数据。首先，作者推测，如果磁场使材料的硬度变软，将有助于提高磨削效率。作者设计并组成了带式无头磨损和磁线圈的磨料磨损试验机，并制作了磁化变频器。实验表明，磁化强度越大，频率越高，磁效应越明显。磁效应被认为是由于振动磁场壁与位错之间的磁弹性相互作用而引起的可动位错密度的增加，并归因于DELTAE效应引起的材料软化。材料在交变磁场中的硬度软化验证了上述解释。此外，还制作了磁场磨削装置，以测试在高摩擦速度下的磨削性能。结果表明，磁效应随磨削速度的增加而减小，在150m/min时下降不到1%。这种速度依赖关系可以解释为磁畴壁的运动速度不是很高。虽然在规律摩擦速度下，磁效应变得很小，但磁效应的有效利用还需要进一步的检验。

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.