A new testing machine to determine the behaviour of aluminium granulate under combined pressure and shear

To reduce the environmental impact and increase the yield from conventional recycling processes of aluminium a direct continuous extrusion method of shredded scrap is being developed. The innovative new method is based on a process where a rotating screw generates the extrusion pressure, introducing rotation to the scrap compacting and extruding in one single process. The objective of this paper is to present a testing machine for compactation of aluminium granulate representing this process in a simplified manner. A machine, which is capable of imposing rotational and linear translations, has been built for the purpose of compacting granulate under different pressures, torques and strain rates at different temperatures to study the influence of these parameters. The compactation of granulate under both high pressure and rotation at elevated temperature is a generic way of representing the thermo-mechanical conditions in this recycling process. The paper describes the developed machine, its features and capabilities in detail. Two initial tests, with and without rotation, have been carried out. The material used was an aluminum alloy AA6060 wire cut in appropriate sizes. It is shown how simultaneous rotation and compression reduce the necessary pressure for full achieving compactation of the granulate.