پرویز ملک زاده

Wear phenomenon is one of the problems that the industry has long been involved with it. For this reason, researchers are constantly looking to improve the wear properties by invention processes or production of new materials. Logical approach to solve this problem, requires careful consideration of the factors affecting it. One of the ways to improve the properties, is the process of nanostructured materials by severe plastic deformation that have experienced rapid development in the past two decades. Constrained groove pressing is one of the severe plastic deformation methods for making nano-materials structure. In this study, tribological characteristics of aluminum alloy before and after the pressing in constrained groove has been investigated by a tribometer under dry wear at room temperature and lubricant wear at 100 Celsius degrees. Microstructure of aluminum samples were analyzed before and after the pressing process. A disc of hardened steel, AISI 52100, has been chosen as the counterpart surface. In general, it was observed that the process of pressing in constrained groove, has been improved wear properties in first pass and the second pass on the increased wear resistance is ineffective. It was concluded that the wear rate is concerned to the factors of moisture, elongation, hardness and grain refinement. In general, the addition of lubricant reduces loss mass compared to dry wear condition. Finally, wear mechanisms were inspected by scanning electron microscopy and X-ray diffraction. It determined that wear mechanisms were ploughing, delamination and oxidation.