Research into Shear Deformation-added Extrusion of Metal-based Powder Using Separated Rotary Container

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Shear deformation-added extrusion of metal-based powder using a separated rotary container devised taking note of the promotion of adhesion between metal powders by shear deformation addition was experimentally studied for its realization. From fundamental experiments on ideal introduction of the shear deformation with aluminum powder whose size is 20-42 in mesh, it was found that concerning a shape of the rotary container its barrel length L should be more than the shortest diagonal distance D of the hexagonal cross-section of the container cavity and that the rotating rate of the container should be set as follows, depending on the pressure acting on the shearing site. Ram travel a revolution of the container should be more than 5mm and 1.5mm when the pressure is 98MPa and 147MPa, respectively. Based on the findings above, continuous consolidation of the aluminum powder by means of step-by-step operation of the devised extrusion method was experimented. In the experiment, an extrusion die with a cross-sectional reduction of 11.5% was used and material feeding was done with pre-compacted powder billets formed by the pressure 147MPa. Contrary to expectation, all the experiments tried ended in failure. The cause of the failure is a sharp increase of extruding force, which made an intrusion of the aluminum powder into the gap between the container and punch and prevented the successive feeding of the material. The failure of the experiment prevented the influence of processing conditions on product's property from being investigated. However, the experiments showed that the boundary produced between the billets fed is completely removable by the introduction of the shear deformation. The findings in the former part of this study have been published, but those in the latter have not yet.