Effect of Magnetostrictive Change in Magnetoplast Roughness During Friction

Studies on the influence of magnetostrictive effect on the surface roughness of composite material have been carried out. It is theoretically established that for iron-based materials (for Co-Fe-V-based alloy particles) with a dispersity of 10–3–10–6 m, changes in surface topography are possible at the nanoscale. For materials with giant magnetostriction (intermetallic compounds), when particles of the same size are used, the change in topography characteristics can be 10–8–10−7m. The surface roughness of composite material containing 70 vol% of powder of magnetostrictive material \({\text{TeFe}}_{2}\) having uniquely high linear magnetostriction (λs = 2 ⋅ 103) in magnetic fields with intensity ~107 A/m was studied. Local changes of surface roughness in the magnetic field were determined and integral changes characterizing the surface as a whole were estimated. It was experimentally established that the change in the height parameters of roughness exceeds 5% (the change in Ra was 10–300 Nm). The magnitude of the effect increases with increasing the field and depends on the scanning area, which is caused by the inhomogeneity of the magnetic structure of the material. The effect detected can be effectively used for contactless change of friction characteristics of friction units with magnetostrictive magnetoplast, precision regulation of tightness of magnetic seals.