Acta Metallurgica最新文献

The Effect of Surface Stress on Crystal-Melt and Crystal-Crystal Equilibrium 表面应力对晶体-熔体和晶体-晶体平衡的影响

Acta Metallurgica Pub Date : 1999-01-01 DOI: 10.1007/978-3-642-59938-5_8

P. Leo, R. Sekerka

引用次数: 61

An in situ x-ray diffraction study of precipitation from a supersaturated solid solution: The γ′ precipitate in a Ni-12.5 at.% A1 alloy 从过饱和固溶体中析出的原位x射线衍射研究:Ni-12.5 at中的γ′沉淀。% A1合金

Acta Metallurgica Pub Date : 1990-11-01 DOI: 10.1016/0956-7151(90)90096-Y

C. Marsh, Haydn Chen

引用次数: 23

Theory for the trapping of disorder and solute in intermetallic phases by rapid solidification 快速凝固法捕获金属间相中无序和溶质的理论

Acta Metallurgica Pub Date : 1989-12-01 DOI: 10.1016/0001-6160(89)90210-1

W.J. Boettinger , M.J. Aziz

{"title":"Theory for the trapping of disorder and solute in intermetallic phases by rapid solidification","authors":"W.J. Boettinger , M.J. Aziz","doi":"10.1016/0001-6160(89)90210-1","DOIUrl":"10.1016/0001-6160(89)90210-1","url":null,"abstract":"<div><p>A theory is developed to predict the long range order parameter, composition and temperature at the interface of a chemically ordered phase as a function of interface velocity and liquid composition during rapid crystal growth. It extends the solute trapping theory of Aziz to a solid phase consisting of two sublattices. The engulfment of atoms randomly on the two sublattices by the rapidly moving liquid-solid interface is balanced against the interdiffusion across the interface that attempts to restore local equilibrium. With increasing interface velocity the theory predicts a progression from the solidification of a phase with equilibrium long range order parameter and with equilibrium solute partitioning to the solidification of a disordered crystalline phase with the same composition as the liqiud. Predictions for solids with free energy functions in which the order disorder transition is first or second order show that the decrease of order parameter to zero with increasing interface velocity will be discontinuous or continuous respectively. Also solute trapping can occur at either a higher or a lower growth rate than disorder trapping depending on the free energy function.</p></div>","PeriodicalId":6969,"journal":{"name":"Acta Metallurgica","volume":"37 12","pages":"Pages 3379-3391"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0001-6160(89)90210-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75909005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 131

Intergranular cavitation during creep in astroloy 星相学蠕变过程中的晶间空化

Acta Metallurgica Pub Date : 1989-12-01 DOI: 10.1016/0001-6160(89)90191-0

M.A. Capano, A.S. Argon, I-W. Chen

引用次数: 10

Neutron irradiation-induced intergranular solute segregation in iron base alloys 中子辐照诱导铁基合金晶间溶质偏析

Acta Metallurgica Pub Date : 1989-12-01 DOI: 10.1016/0001-6160(89)90201-0

J. Kameda, A.J. Bevolo

{"title":"Neutron irradiation-induced intergranular solute segregation in iron base alloys","authors":"J. Kameda, A.J. Bevolo","doi":"10.1016/0001-6160(89)90201-0","DOIUrl":"10.1016/0001-6160(89)90201-0","url":null,"abstract":"<div><p>The effect of neutron irradiation (9.4 × 10<sup>22</sup> n/m<sup>2</sup> at 395°C) on solute segregation to grain or interfacial boundaries in several iron base alloys doped with P, Cu and/or C has been investigated using scanning Auger microscopy. It was found by fracture surface Auger analyses that while neutron irradiation enhanced intergranular segregation of S in a Cu-doped alloy with the absence of P segregation, it mitigated S segregation and promoted P segregation in P containing alloys. The quantity of segregated P was much greater for the irradiated alloys than for the thermally 1000 h aged alloys. The P-doped alloy showed a stronger effect of neutron irradiation on the enrichment of P segregation than the P-Cu-doped and P-C-doped alloys. Argon sputtering experiments indicated that the segregation profiles for S and P were more broadly and narrowly distributed during irradiation, respectively. A remarkable transition of the P segregation profile was observed near the interface of particles lying along grain boundaries where S was preferentially segregated because of the competitive segregation between S and P. The mechanism for neutron irradiation-induced solute segregation is discussed in light of inverse Kirkendall effects and the formation of defect-solute complexes arising from the dynamic interaction between solute and defect fluxes. The relationship of intergranular solute segregation to embrittlement is presented.</p></div>","PeriodicalId":6969,"journal":{"name":"Acta Metallurgica","volume":"37 12","pages":"Pages 3283-3296"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0001-6160(89)90201-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74190536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 27

Electrical resistivity of fatigued copper crystals 疲劳铜晶体的电阻率

Acta Metallurgica Pub Date : 1989-12-01 DOI: 10.1016/0001-6160(89)90200-9

Z.S. Basinski, S.J. Basinski

引用次数: 35

Influence of plastic deformation on hydrogen diffusion and permeation in stainless steels 塑性变形对不锈钢中氢扩散和渗透的影响

Acta Metallurgica Pub Date : 1989-12-01 DOI: 10.1016/0001-6160(89)90211-3

T-P. Perng, M. Johnson, C.J. Altstetter

引用次数: 45

Diffusional relaxation around martensitically transformed Fe-Co particles in a Cu matrix Cu基体中马氏体相变Fe-Co颗粒周围的扩散弛豫

Acta Metallurgica Pub Date : 1989-12-01 DOI: 10.1016/0001-6160(89)90189-2

R. Monzen , M. Kato , T. Mori

引用次数: 18

Characterization and crystallization studies of melt-spun glassy Fe-22.5Al-10Zr Metal by analytical electron microscopy Fe-22.5Al-10Zr金属熔纺玻璃态的分析电镜表征与结晶研究

Acta Metallurgica Pub Date : 1989-12-01 DOI: 10.1016/0001-6160(89)90212-5

C.C. Cheng , W.E. King , M.J. McNallan

{"title":"Characterization and crystallization studies of melt-spun glassy Fe-22.5Al-10Zr Metal by analytical electron microscopy","authors":"C.C. Cheng , W.E. King , M.J. McNallan","doi":"10.1016/0001-6160(89)90212-5","DOIUrl":"10.1016/0001-6160(89)90212-5","url":null,"abstract":"<div><p>Melt-spun glassy Fe-22.5Al-10Zr metal (concentration in atomic percent) is an interesting material for high temperature oxidation study due to its high crystallization temperature, 650°C, and its capacity to form a protective oxide layer. We have applied analytical electron microscopy on cross-section samples to study the composition variation near the two surfaces of the melt-spun ribbon. An aluminum depleted layer was detected using X-ray energy dispersive spectroscopy ≈200 nm beneath the He-cooled surface. No composition variation was observed as a function of depth below the wheel-cooled surface. The crystallization behavior of this material both below and above the crystallization temperature was also studied. Crystallization begins with the nucleation of α-Fe particles via a primary crystallization mechanism followed by the formation of a metastable phase, Fe<sub>8</sub>Al<sub>3</sub>Zr, via polymorphic crystallization. At 700°C, above the crystallization temperature, the Fe<sub>8</sub>Al<sub>3</sub>Zr transformed to the equilibrium phase, Fe<sub>10</sub>Al<sub>4</sub>Zr<sub>3</sub>, by solid state reaction.</p></div>","PeriodicalId":6969,"journal":{"name":"Acta Metallurgica","volume":"37 12","pages":"Pages 3399-3407"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0001-6160(89)90212-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85271792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Microband formation in shock-loaded and quasi-statically deformed metals 冲击载荷和准静态变形金属中的微带形成

Acta Metallurgica Pub Date : 1989-12-01 DOI: 10.1016/0001-6160(89)90206-X

J.C. Huang , G.T. Gray III

{"title":"Microband formation in shock-loaded and quasi-statically deformed metals","authors":"J.C. Huang , G.T. Gray III","doi":"10.1016/0001-6160(89)90206-X","DOIUrl":"10.1016/0001-6160(89)90206-X","url":null,"abstract":"<div><p>A systematic examination of microbands developed in various materials, including pure Al, Cu, Ag, Nb metals and Al-Mg, 6061 Al and Al-Li-Cu alloys, deformed dynamically or quasi-statically to intermediate strains has been conducted. Based on extensive characterization of microbands using transmission electron microscopy, the characteristics of microbands do not appear to be strongly dependent on crystal structure, material properties, strain level or deformation path. This finding suggests that the formation mechanism of microbands may be similar in a variety of f.c.c. and b.c.c. metals and alloys. A possible microband formation mechanism is proposed, based on a concept of the further development of coarse slip bands (or dislocation tangles on glide planes), which is consistent with experimental observations. The model involves first the generation of polarized dislocations on primary slip systems, followed by an annihilation process for the primary dislocations in the central portion of a band structure, forming double dislocation walls parallel to the primary slip planes. Misorientation inside the double walls is believed to be caused by the directional shear of primary dislocations. Secondary slip is then induced by the internal stresses in the region between the double walls. Finally a stable dislocation configuration is created as a result of the interaction between the primary and secondary dislocations. The proposed model is in agreement with several observed phenomena, including the constancy of microband thickness, tilt axis, shear sense, and uniform shear strain over the cross-section of a microband. The roles of stacking fault energy, solute atoms and precipitates on microband formation are also discussed.</p></div>","PeriodicalId":6969,"journal":{"name":"Acta Metallurgica","volume":"37 12","pages":"Pages 3335-3347"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0001-6160(89)90206-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78883228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 107