Microstructural evolution of Cu-1at% Ti alloy aged in a hydrogen atmosphere and its relation with the electrical conductivity

Handle URI:
http://hdl.handle.net/10754/575665
Title:
Microstructural evolution of Cu-1at% Ti alloy aged in a hydrogen atmosphere and its relation with the electrical conductivity
Authors:
Semboshi, Satoshi; Al-Kassab, Talaat; Gemma, Ryota; Kirchheim, Reiner
Abstract:
Copper alloys with titanium additions between 1 and 6 at% Ti emerge currently as attractive conductive materials for electrical and electronic commercial products, since they exhibit superior mechanical and electrical properties. However, their electrical conductivity is reduced owing to the residual amount of Ti solutes in the Cu solid solution (Cu(ss)) phase. Since Cu shows only poor reactivity with hydrogen (H), while Ti exhibits high affinity to it, we were inspired by the idea that hydrogenation of Cu-Ti alloys would influence their microstructure, resulting in a significant change of their properties. In this contribution, the influence of aging under a deuterium (D(2)) atmosphere of Cu-1 at% Ti alloys on their microstructure is investigated to explore the effects on the electrical conductivity. The specimens were investigated by means of transmission electron microscopy (TEM), field ion microscopy (FIM), computer-aided field ion image tomography (cFIIT), and atom probe tomography (APT). At an early aging stage at 623 K in a D(2) atmosphere of 0.08 Wit, ellipsoidal alpha-Cu(4)Ti precipitates are formed in the alloy, and during subsequent aging, delta-TiD(2) is competitively nucleated instead of growth of alpha-Cu(4)Ti particles. The co-precipitation of alpha-Cu(4)Ti and delta-TiD(2) efficiently reduces the Ti concentration of Cuss matrix, particularly in the later aging stages in comparison to the aging in vacuum conditions. The electrical conductivity of the alloy aged in the D(2) atmosphere increases steeply up to 48% International Annealed Copper Standard (IACS) after 1030 It, while it saturates to approximately 20% IACS in the alloy aged in vacuum. The outstanding increase of electrical conductivity during aging in D2 atmosphere can be basically explained by the reduction of Ti solute concentration in Cuss matrix. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.
KAUST Department:
Materials Science and Engineering Program
Publisher:
Elsevier BV
Journal:
Ultramicroscopy
Issue Date:
Apr-2009
DOI:
10.1016/j.ultramic.2008.10.015
Type:
Article
ISSN:
0304-3991
Appears in Collections:
Articles; Materials Science and Engineering Program

Full metadata record

DC FieldValue Language
dc.contributor.authorSemboshi, Satoshien
dc.contributor.authorAl-Kassab, Talaaten
dc.contributor.authorGemma, Ryotaen
dc.contributor.authorKirchheim, Reineren
dc.date.accessioned2015-08-24T08:35:22Zen
dc.date.available2015-08-24T08:35:22Zen
dc.date.issued2009-04en
dc.identifier.issn0304-3991en
dc.identifier.doi10.1016/j.ultramic.2008.10.015en
dc.identifier.urihttp://hdl.handle.net/10754/575665en
dc.description.abstractCopper alloys with titanium additions between 1 and 6 at% Ti emerge currently as attractive conductive materials for electrical and electronic commercial products, since they exhibit superior mechanical and electrical properties. However, their electrical conductivity is reduced owing to the residual amount of Ti solutes in the Cu solid solution (Cu(ss)) phase. Since Cu shows only poor reactivity with hydrogen (H), while Ti exhibits high affinity to it, we were inspired by the idea that hydrogenation of Cu-Ti alloys would influence their microstructure, resulting in a significant change of their properties. In this contribution, the influence of aging under a deuterium (D(2)) atmosphere of Cu-1 at% Ti alloys on their microstructure is investigated to explore the effects on the electrical conductivity. The specimens were investigated by means of transmission electron microscopy (TEM), field ion microscopy (FIM), computer-aided field ion image tomography (cFIIT), and atom probe tomography (APT). At an early aging stage at 623 K in a D(2) atmosphere of 0.08 Wit, ellipsoidal alpha-Cu(4)Ti precipitates are formed in the alloy, and during subsequent aging, delta-TiD(2) is competitively nucleated instead of growth of alpha-Cu(4)Ti particles. The co-precipitation of alpha-Cu(4)Ti and delta-TiD(2) efficiently reduces the Ti concentration of Cuss matrix, particularly in the later aging stages in comparison to the aging in vacuum conditions. The electrical conductivity of the alloy aged in the D(2) atmosphere increases steeply up to 48% International Annealed Copper Standard (IACS) after 1030 It, while it saturates to approximately 20% IACS in the alloy aged in vacuum. The outstanding increase of electrical conductivity during aging in D2 atmosphere can be basically explained by the reduction of Ti solute concentration in Cuss matrix. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.en
dc.publisherElsevier BVen
dc.titleMicrostructural evolution of Cu-1at% Ti alloy aged in a hydrogen atmosphere and its relation with the electrical conductivityen
dc.typeArticleen
dc.contributor.departmentMaterials Science and Engineering Programen
dc.identifier.journalUltramicroscopyen
dc.contributor.institutionInst Mat Phys, D-37077 Gottingen, Germanyen
dc.contributor.institutionOsaka Prefecture Univ, Dept Mat Sci, Sakai, Osaka 5998531, Japanen
kaust.authorAl-Kassab, Talaaten
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