1994 Fiscal Year Final Research Report Summary
Study on Forming of Hollow Sections of Copper and Copper Alloys by MULTI-BILLET EXTRUSION Method
| Project/Area Number |
05452288
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Material processing/treatments
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
XIE Jian-xin Tohoku University, Faculty of Eng., Associate Professor, 工学部, 助教授 (80235697)
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| Co-Investigator(Kenkyū-buntansha) |
MURAKAMI Tadasu Tohoku University, Faculty of Eng., Associate Professor, 工学部, 助教授 (90005447)
IKEDA Keisuke Tohoku University, Faculty of Eng., Professor, 工学部, 教授 (40005921)
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| Project Period (FY) |
1993 – 1994
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| Keywords | extrusion / multi-billet / hollow section / metal forming / new forming method / copper alloy / numerical simulation / die design |
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| Research Abstract |
To confirm the practicality of the Multi-Billet Extrusion method, fabrication of hollow sections of copper (C1100) and copper alloys (C2600, C3771) has been attempted with four-billet extrusion. Six kinds of sections were extruded at 750ﾟC for C1100 and C2600 and at 700ﾟC for C3771 in argon atmosphere. The argon atmosphere was supplied to guard against the production of the oxide film on the billet surface resulted from heating, because the thick oxide film is harmful to solid-state welding during extrusion, which is known from early investigation. The welded state of extrudates was evaluated by the expansion test as well as the observations on the welded portions by optical microscopy and on the welded interface by SEM.In most cases, the expanding crack occurs at non-welded portion of extrudates. The expanding ratio, PSI is greater than 1.65 for C1100 extrudates and 1.30 for C2600 extrudates in as-extruded state. For C3771 extrudates, PSI is greater than 1.20 in as-extruded and 1.35 in annealed state. All the expanding ratios are greater than the JIS standard values for seamless pipes of copper or copper alloys. The welded seams of billets on cross-sections of extrudates are invisible in optical microstructure. Even for the cases in which the expanding crack occurs at the welded portion, a large number of dimples exist and only a small amount oxide particles are observed in the fracture surface through SEM observation. The Multi-Billet Extrusion method is feasible for forming hollow sections of copper and copper alloys.
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Research Products
(6 results)
