M.Sc Tezi Görüntüleme

      In the firs part of this work, the mechanical properties of aluminium, copper, bronze and brass materials were determined by compression tests. Later, ring compression tests were made with standard sized specimens prepared under different lubricating conditions.

      Also, in the open-die backward extrusion test; the specimen is compressed between the two flat plates, but here, the upper die has a hole in the middle and the specimen is in the form of solid cylinder. In order to determine the effects of the geometries of the specimen and die on friction coefficient, for only aluminium specimen using three different lubrication in three different rates of H/D and in two different rates of d/D, these experiments were performed.

      In the second part of the work, the effects of different materials, different lubrication conditions and barrelling on calibration curves were investigated by means of FORTRAN programming language and finite element modeling. Finally, to determine friction coefficient, open-die backward extrusion test which was developed as an alternative method and the effects of lubrication conditions and die geometries on friction calibration curve were investigated. It has determined that these geometries has affected the friction calibration curves.

      As a result of this study, each material have its own proper friction calibration curves. Theoric analyses that was done for ring compression test was insufficient. Coefficient of friction could not be determined definitely by coefficient of friction measurement technique which depends on metal forming.

      Key Words : Measurement of Coefficient of Friction, Metal Forming Processes, Finite Element Modeling, Nonlinear Solution