TORSION SEVERE PLASTIC DEFORMATION METHOD OF CONICAL METAL TUBE FOR APPLYING SHEAR STRESS THROUGH A COMPRESSIVE FORCE AND TORSION TO A CONICAL METAL TUBE WHICH ALSO SUBSTANTIALLY MAINTAINS THE SHAPE

摘要

PURPOSE: A torsion severe plastic deformation method of conical metal tube is provided to make a micro-structure to microcrystalline or nano-crystalline, thereby improving the mechanical property of conical metal tube.;CONSTITUTION: A torsion severe plastic deformation method of conical metal tube performs the following steps. A punch suitable for the inner shape of the conical metal pipe is mounted in the inside of conical metal pipe. A mold suitable for the outer shape of the conical metal pipe is mounted in the outside of conical metal pipe. A micro-structure of conical metal pipe is formed into microcrystalline or nano-crystalline through the shear deformation obtained by applying the compression and torsion to the conical metal pipe by means of the punch and the mold. The shear deformation is obtained by rotating the punch after the punch is pressured by the mold.;COPYRIGHT KIPO 2013;[Reference numerals] (AA) Initial piece shape; (BB) After process piece shape; (CC) Piece input step; (DD) Mold insertion step; (EE) Twisting; (FF) Compression and twisting step; (GG) Compression strength