Kirchheim, Reiner

[["dc.bibliographiccitation.firstpage","2198"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","Journal of Materials Science"],["dc.bibliographiccitation.lastpage","2205"],["dc.bibliographiccitation.volume","44"],["dc.contributor.author","Gegner, J."],["dc.contributor.author","Hoerz, G."],["dc.contributor.author","Kirchheim, Reiner"],["dc.date.accessioned","2018-11-07T08:30:23Z"],["dc.date.available","2018-11-07T08:30:23Z"],["dc.date.issued","2009"],["dc.description.abstract","The solid solubility c(O) of oxygen in palladium in equilibrium with gaseous oxygen has been determined from absorption-desorption experiments for temperatures T of 1123 and 1173 K and oxygen partial pressures p(O2) between 2.7 x 10(3) and 4.0 x 10(4) Pa. The relationship between c(O), p(O2) and T is given by c(O) = a root p(O2) exp(-Delta H(s)/RT), where R = 8.314 JK(-1) mol(-1) is the universal gas constant, Delta H(s) = - 13.55 kJ/mol denotes the heat of solution of oxygen in palladium and the constant a amounts to 4.26 x 10(-5) at.%/root Pa or 6.41 x 10(-8) wt%/root Pa. The diffusion coefficient D(O) of oxygen in solid palladium has been determined by incomplete isothermal internal oxidation of Pd-Fe alloys using the data on the oxygen solubility in palladium. The temperature dependence of D(O) obeys the Arrhenius equation D(O) = D(0)exp(-E(d)/RT) with pre-exponential factor D(0) = 2.33 x 10(-7) m(2)/s and activation energy of diffusion of oxygen in palladium, E(d) = 102.76 kJ/mol"],["dc.identifier.doi","10.1007/s10853-008-2923-4"],["dc.identifier.isi","000265214500004"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11184"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/16885"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","0022-2461"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","Diffusivity and solubility of oxygen in solid palladium"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","99"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Procedia Engineering"],["dc.bibliographiccitation.lastpage","103"],["dc.bibliographiccitation.volume","1"],["dc.contributor.author","Cizek, J."],["dc.contributor.author","Prochazka, I."],["dc.contributor.author","Vlach, M."],["dc.contributor.author","Zaludova, N."],["dc.contributor.author","Dobron, P."],["dc.contributor.author","Chmelik, F."],["dc.contributor.author","Brauer, G."],["dc.contributor.author","Anwand, W."],["dc.contributor.author","Mücklich, A."],["dc.contributor.author","Nikitin, E."],["dc.contributor.author","Gemma, R."],["dc.contributor.author","Pundt, A."],["dc.contributor.author","Kirchheim, R."],["dc.date.accessioned","2019-07-09T11:40:46Z"],["dc.date.available","2019-07-09T11:40:46Z"],["dc.date.issued","2009"],["dc.description.abstract","Hydrogen loading causes a significant volume expansion, which is isotropic in free-standing bulk materials. Contrary to bulk samples, thin films are clamped to an elastically stiff substrate, which prevents in-plane expansion. Hence, volume expansion of a thin film is strongly anisotropic because it expands only in the out-of-plane direction. High internal stresses introduced during hydrogen loading may lead to a situation when detachment of film from the substrate is energetically favorable. In the present work, we studied hydrogen-induced buckling of thin Pd films using a multi-scale approach. Defects in buckled films were characterized on the atomic level by positron annihilation spectroscopy combined with microstructure studies by transmission electron microscopy. Meso-scale measurements were performed by acoustics emission. Observations at the macroscopic level were performed by optical microscopy. It was found that buckling of thin films occurs at hydrogen concentrations xH>0.1. Defect studies of buckled Pd films revealed a significant increase of dislocation density in agreement with acoustic emission studies which demonstrated a correlated movement of dislocations with a well-defined threshold coinciding with the onset of buckling."],["dc.identifier.doi","10.1016/j.proeng.2009.06.024"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11293"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/58244"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation.issn","1877-7058"],["dc.relation.orgunit","Fakultät für Physik"],["dc.rights","CC BY-NC-ND 3.0"],["dc.rights.uri","http://creativecommons.org/licenses/by-nc-nd/3.0/"],["dc.title","Multi-scale analysis of hydrogen-induced buckling in Pd films"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","2136"],["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science"],["dc.bibliographiccitation.lastpage","2143"],["dc.bibliographiccitation.volume","42A"],["dc.contributor.author","Semboshi, Satoshi"],["dc.contributor.author","Nishida, Tomoya"],["dc.contributor.author","Numakura, Hiroshi"],["dc.contributor.author","Al-Kassab, Tala'at"],["dc.contributor.author","Kirchheim, Reiner"],["dc.date.accessioned","2018-11-07T08:54:09Z"],["dc.date.available","2018-11-07T08:54:09Z"],["dc.date.issued","2011"],["dc.description.abstract","To improve the balance of the electrical conductivity and mechanical strength for dilute Cu-Ti alloys by aging in a hydrogen atmosphere, the influence of aging temperature ranging from 673 K to 773 K (400 A degrees C to 500 A degrees C) on the properties of Cu-3 at. pct Ti alloy was studied. The Vickers hardness increases steadily with aging time and starts to fall at 3 hours at 773 K (500 A degrees C), 10 hours at 723 K (450 A degrees C), or over 620 hours at 673 K (400 A degrees C), which is the same as the case of conventional aging in vacuum. The maximum hardness increases from 220 to 236 with the decrease of aging temperature, which is slightly lower than aging at the same temperature in vacuum. The electrical conductivity at the maximum hardness also increases from 18 to 32 pct of pure copper with the decrease of the temperature, which is enhanced by a factor of 1.3 to 1.5 in comparison to aging in vacuum. Thus, aging at 673 K (400 A degrees C) in a hydrogen atmosphere renders fairly good balance of strength and conductivity, although it takes nearly a month to achieve. The microstructural changes during aging were examined by transmission electron microscopy (TEM) and atom-probe tomography (APT), and it was confirmed that precipitation of the Cu(4)Ti phase occurs first and then particles of TiH(2) form as the third phase, thereby efficiently removing the Ti solutes in the matrix."],["dc.identifier.doi","10.1007/s11661-011-0637-8"],["dc.identifier.isi","000291704200002"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/7377"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/22605"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","1073-5623"],["dc.relation.orgunit","Fakultät für Physik"],["dc.rights","Goescholar"],["dc.rights.uri","https://goedoc.uni-goettingen.de/licenses"],["dc.title","Effects of Aging Temperature on Electrical Conductivity and Hardness of Cu-3 at. pct Ti Alloy Aged in a Hydrogen Atmosphere"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]