الفهرس | Only 14 pages are availabe for public view |
Abstract The machinability term is not a clear and definit concept. This matter is accompanied by a large variety of quantitative definitions. The parameters and variables of any machining operation are the causes for the variation of machinability criteria. The search for a new machinability criterion satisfies the conditions of machining process and simplifies this criterion, are still continuous. This thesis tries to investigate a new criterion for machinability of workpiece materials, based on the scratchability of the tool materials. This study suggests a correlation between the machinability ratings such as tool life and machinability index rations, and the scratchability indices. The literature also introduces some indices for quantitative measuring scrachability. This can be done by considering only the geometry and shape of a scratched groove in the metal by using a cutter of prescribed shape. The results indicate agood agreement between these two criteria of workpiece and tool materials ( machinability and scratchability). In any machining operation, when the tool used has a good scratchability, the workpiece material has a good machinability from view of surface finish criterion and bad machinability from w.r.t. tool life criterion. |