Mechanical ALloying of FE-Based Solid Lubricant COmposite Powders

摘要

Tribological problems are of very high intrest in modern research fields of mechanical engineering[1]. In order to obtain low frition coefficients and an efficent self lubrication behaviour under high and low temperature conditions as well as under vacuum which is problematic in case of using conventional oil lubricants, several alloying systems were produced and investigatedwith respet to their structural properties. As previous experiments have shown, the mechanical alliyig process in a ball mill is a convenient technique to get highly disprsed phase distributions on a nanocrystalline scale[2-4]. Therefore the powder procesisng was carried out in a aimoloyer to achieve a homogeneous phase distribution of the solid lubricants in a strong metallic matrix. All mechanically alloyed powders produced exhibit a fast dispersio of the solid lubricants in the Fe-matrix during processing. First investigations showed that the hexagonal structure of the solid lubricants which is essential for hte sliding effect is completely changed under the influence of the colliding milling balls. This effect could be observed especially in the case of pure milled graphit powder, where the crystalline structure changed to a nanocrystalline phase already after a very short procesing time. Further milling leads to ana morphous structure. Similar results were found by other authors [5,6] after long milling durations in planetray ball mills.