公开(公告)号：US20170342537A1

公开(公告)日：2017-11-30

申请号：US15538407

申请日：2015-04-23

Applicant: AGENCY FOR DEFENSE DEVELOPMENT

Inventor： Seong LEE ,  Seongho YANG ,  Sungho LEE ,  Hyotae JEONG ,  Yuyeon JO

IPC: C22F1/18

CPC classification number: C22F1/18 ,  B21J5/08

Abstract: A method for controlling the microstructure and texture of tantalum, proposed in the present invention, comprises: a step for performing cold working on a tantalum billet having the shape of a rectangular prism; and a step for performing cold rolling multiple times, wherein the step for performing the cold working includes: a first forging step for performing upset forging and come-back forging on the tantalum billet multiple times in different directions, the upset forging being performed to press two surfaces of the tantalum billet in order to make the two surfaces close to each other and the come-back forging being performed to restore the tantalum billet to the original shape; and a second forging step for performing wedge forging and come-back forging on the tantalum billet multiple times in different directions, the wedge forging being performed to press two edges located in a diagonal direction of the tantalum billet and parallel to each other in order to make the two edges close to each other and the come-back forging being performed to restore the tantalum billet to the original shape.

公开(公告)号：US20180056378A1

公开(公告)日：2018-03-01

申请号：US15610764

申请日：2017-06-01

Applicant: AGENCY FOR DEFENSE DEVELOPMENT

Inventor： Seong LEE ,  Seong-Ho YANG ,  Lee-Ju PARK ,  Hak-Jun KIM ,  Hyoung-Seop KIM ,  See-Am LEE ,  Ho-Yong UM

IPC: B22D13/02 ,  B22F5/10 ,  B22F5/00 ,  B22F3/00

CPC classification number: B22D13/02 ,  B21D22/02 ,  B21D31/00 ,  B21D51/10 ,  B22F3/00 ,  B22F5/007 ,  B22F5/106 ,  E21B43/126 ,  E21B43/26

Abstract: In a localized torsional severe plastic deformation method for conical tube metal, a desired region of a conical tube metal can be subjected to severe plastic deformation using molds in which roughness is formed at predetermined regions. The method includes roughening a predetermined region of each of the molds; sticking the conical tube metal only to the roughened regions of the molds; moving the lower mold toward the upper mold to apply a load to the conical tube metal; and rotating the molds to apply severe plastic deformation to the conical tube metal only at the regions stuck to the roughened regions of the molds.