The significance of self-annealing at room temperature in high purity copper processed by high-pressure torsion

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:656

Article

Huang, Yi¹  Sabbaghianrad, Shima^2,3  Almazrouee, Abdulla I.⁴  Al-Fadhalah, Khaled J.⁵  Alhajeri, Saleh N.⁴  Langdon, Terence G.^1,2,3 

[1] Univ Southampton, Fac Engn & Environm, Mat Res Grp, Southampton SO17 1BJ, Hants, England

[2] Univ So Calif, Dept Aerosp & Mech Engn, Los Angeles, CA 90089 USA

[3] Univ So Calif, Dept Mat Sci, Los Angeles, CA 90089 USA

[4] PAAET, Coll Technol Studies, Dept Mfg Engn, POB 42325, Shuwaikh 70654, Kuwait

[5] Kuwait Univ, Dept Mech Engn, Coll Engn & Petr, POB 5969, Safat 13060, Kuwait

关键词: Copper;    Grain growth;    Hardness;    High-pressure torsion;    Self-annealing;   

DOI  :  10.1016/j.msea.2016.01.027

来源: Elsevier

【 摘 要 】

High purity copper was processed by high-pressure torsion (HPT) at room temperature and then stored at room temperature for periods of up to 6 weeks to investigate the effect of self-annealing. Hardness measurements were recorded both at 48 h after HPT processing and after various storage times. The results show the occurrence of recovery near the edges of the discs after processing through 1/2 and I turn and this leads to a significant drop in the measured hardness values which is accompanied by microstructural evidence for abnormal grain growth. Conversely, there was no recovery, and therefore no hardness drops, after processing through 5 and 10 turns. X-ray line profile analysis was used to determine the crystallite sizes and dislocation densities at 1 h after HPT and after storage for different times. The results show a good thermal stability in high purity Cu after processing through more than 1 turn of HPT but care must be exercised in recording hardness measurements when processing through only fractional or very small numbers of turns. (C) 2016 Elsevier B.V. All rights reserved.

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