Pub Date : 1900-01-01DOI: 10.1179/030634570790444086
W. McCarthy, J. Shyne, O. Sherby
AbstractTwo types of zinc-base composite have been studied, one containing networks of zinc oxide and the other particles of zinc oxide dispersed within the metal matrix. The composites containing zinc-oxide networks possessed mechanical strength at above the melting point of zinc; those containing discontinuous dispersoids had no measurable strength at such temperatures. These results tend to confirm an earlier suggestion that commercial sintered aluminium powder products (SAP) contain a continuous network of alumina dispersed throughout the aluminium matrix.
{"title":"Compression Strength of Zinc/Zinc Oxide Composites at Temperatures above the Melting Point of Zinc","authors":"W. McCarthy, J. Shyne, O. Sherby","doi":"10.1179/030634570790444086","DOIUrl":"https://doi.org/10.1179/030634570790444086","url":null,"abstract":"AbstractTwo types of zinc-base composite have been studied, one containing networks of zinc oxide and the other particles of zinc oxide dispersed within the metal matrix. The composites containing zinc-oxide networks possessed mechanical strength at above the melting point of zinc; those containing discontinuous dispersoids had no measurable strength at such temperatures. These results tend to confirm an earlier suggestion that commercial sintered aluminium powder products (SAP) contain a continuous network of alumina dispersed throughout the aluminium matrix.","PeriodicalId":103313,"journal":{"name":"Metal Science Journal","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129609880","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}
Pub Date : 1900-01-01DOI: 10.1179/030634572790445948
E. D. Hondros
AbstractIntergranular embrittlement induced by equilibrium segregation of solutes is now recognized in a number of engineering alloys, particularly in ferrous systems. In such multicomponent systems, grain-boundary segregation effects can be quite complex, with competitive interactions among a number of surface-active species. Consequently, the model binary system copper-bismuth has been used here in an attempt to relate, quantitatively, grain-boundary fragility with grainboundary segregation. The experimental approach has been to measure the dependence of both the interface energies and the mechanical strength on bulk bismuth content. The results show that the brittleness is due to grain-boundary decohesion, which can be related to the adsorption of bisnluth to the grain boundaries.
{"title":"Grain-Boundary Fragility and Segregation","authors":"E. D. Hondros","doi":"10.1179/030634572790445948","DOIUrl":"https://doi.org/10.1179/030634572790445948","url":null,"abstract":"AbstractIntergranular embrittlement induced by equilibrium segregation of solutes is now recognized in a number of engineering alloys, particularly in ferrous systems. In such multicomponent systems, grain-boundary segregation effects can be quite complex, with competitive interactions among a number of surface-active species. Consequently, the model binary system copper-bismuth has been used here in an attempt to relate, quantitatively, grain-boundary fragility with grainboundary segregation. The experimental approach has been to measure the dependence of both the interface energies and the mechanical strength on bulk bismuth content. The results show that the brittleness is due to grain-boundary decohesion, which can be related to the adsorption of bisnluth to the grain boundaries.","PeriodicalId":103313,"journal":{"name":"Metal Science Journal","volume":"12 16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128998347","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}
Pub Date : 1900-01-01DOI: 10.1179/MSC.1967.1.1.202
G. Carpenter, R. Garwood
AbstractThe effect of drastic water-quenching on the kinetics and mode of precipitation in an aluminium-22.5% zinc alloy has been studied during ageing at elevated temperatures. As with direct-quenching, decomposition occurs in four stages: G.P. zones → platelets of rhombohedral transition phase → cubic α′ → zinc. The loops and helical dislocations introduced by quenching from 475°C do not appreciably affect the initial stages of precipitation but accelerate by a factor of ∼ 5 the conversion of the rhombohedral precipitate into cubic α′ and ultimately zinc. The effect is believed to be due to the more rapid loss of coherency and coarsening of precipitates nucleated on the dislocations. Other factors studied or discussed are the geometry of the precipitation of rhombohedral α′ platelets on dislocations, the direct precipitation of zinc at temperatures above the metastable α−α′ solvus, and the conversion of the α′ platelets into zinc during storage at room temperature after the completion of heat-treatment....
{"title":"The Ageing of a Quenched Aluminium-22.5% Zinc Alloy","authors":"G. Carpenter, R. Garwood","doi":"10.1179/MSC.1967.1.1.202","DOIUrl":"https://doi.org/10.1179/MSC.1967.1.1.202","url":null,"abstract":"AbstractThe effect of drastic water-quenching on the kinetics and mode of precipitation in an aluminium-22.5% zinc alloy has been studied during ageing at elevated temperatures. As with direct-quenching, decomposition occurs in four stages: G.P. zones → platelets of rhombohedral transition phase → cubic α′ → zinc. The loops and helical dislocations introduced by quenching from 475°C do not appreciably affect the initial stages of precipitation but accelerate by a factor of ∼ 5 the conversion of the rhombohedral precipitate into cubic α′ and ultimately zinc. The effect is believed to be due to the more rapid loss of coherency and coarsening of precipitates nucleated on the dislocations. Other factors studied or discussed are the geometry of the precipitation of rhombohedral α′ platelets on dislocations, the direct precipitation of zinc at temperatures above the metastable α−α′ solvus, and the conversion of the α′ platelets into zinc during storage at room temperature after the completion of heat-treatment....","PeriodicalId":103313,"journal":{"name":"Metal Science Journal","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130589953","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}
Pub Date : 1900-01-01DOI: 10.1179/030634568790511507
H. Williams, C. Corti
Abstract High-purity copper, magnesium, and Magnox AL80 have been fatigued at temperatures of 0.5T m and above. Grain-boundary migration and cavitation were observed after fatigue, and quantitative measurements of the angular distributions of total and cavitated boundaries were made. These showed that grain boundaries tended to migrate to planes of maximum shear stress during fatigue, the driving force most probably being provided by the imbalance of dislocations across boundaries due to inhomogeneity of slip. Similarly, the incidence of cavitated boundaries showed a maximum around the planes of maximum shear stress. The results support the theory of the growth of cavities by absorption of lattice vacancies continuously generated in the grains by alternating plastic strain.
{"title":"Grain-Boundary Migration and Cavitation during Fatigue","authors":"H. Williams, C. Corti","doi":"10.1179/030634568790511507","DOIUrl":"https://doi.org/10.1179/030634568790511507","url":null,"abstract":"Abstract High-purity copper, magnesium, and Magnox AL80 have been fatigued at temperatures of 0.5T m and above. Grain-boundary migration and cavitation were observed after fatigue, and quantitative measurements of the angular distributions of total and cavitated boundaries were made. These showed that grain boundaries tended to migrate to planes of maximum shear stress during fatigue, the driving force most probably being provided by the imbalance of dislocations across boundaries due to inhomogeneity of slip. Similarly, the incidence of cavitated boundaries showed a maximum around the planes of maximum shear stress. The results support the theory of the growth of cavities by absorption of lattice vacancies continuously generated in the grains by alternating plastic strain.","PeriodicalId":103313,"journal":{"name":"Metal Science Journal","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130650384","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}
Pub Date : 1900-01-01DOI: 10.1179/MSC.1969.3.1.201
E. Anderson, R. Bode, J. E. Dorn, J. Spreadborough
AbstractThe low-temperature tensile properties of dilute Fe–C, Fe–Nb–C, Fe–V–C, Fe–N, Fe–Nb–V–N, and Fe–V–N steels have been analysed. The major differences in the plastic behaviour of the alloys arise from their athermal stress/strain behaviour. The lower yield strength vs. temperature relations correspond qualitatively with the Peierls mechanism for thermally activated deformation. The activation volumes also agree well with expectations based only on the Peierls mechanism. The results suggest that the Peierls stress, kink energy, and shapes of the Peierls hills are insensitive to alloy composition and heat-treatment. The fact that higher yield stresses at 298° K also gave higher values of Tc , the temperature at which plastic behaviour becomes athermal, has been interpreted to mean that the product, ρL, of the density of mobile dislocations times the dislocation length swept out by a pair of kinks decreased as the athermal component of stress increased.
{"title":"Effects of Alloying Elements on the Mechanical Properties of Steels at Low Temperatures","authors":"E. Anderson, R. Bode, J. E. Dorn, J. Spreadborough","doi":"10.1179/MSC.1969.3.1.201","DOIUrl":"https://doi.org/10.1179/MSC.1969.3.1.201","url":null,"abstract":"AbstractThe low-temperature tensile properties of dilute Fe–C, Fe–Nb–C, Fe–V–C, Fe–N, Fe–Nb–V–N, and Fe–V–N steels have been analysed. The major differences in the plastic behaviour of the alloys arise from their athermal stress/strain behaviour. The lower yield strength vs. temperature relations correspond qualitatively with the Peierls mechanism for thermally activated deformation. The activation volumes also agree well with expectations based only on the Peierls mechanism. The results suggest that the Peierls stress, kink energy, and shapes of the Peierls hills are insensitive to alloy composition and heat-treatment. The fact that higher yield stresses at 298° K also gave higher values of Tc , the temperature at which plastic behaviour becomes athermal, has been interpreted to mean that the product, ρL, of the density of mobile dislocations times the dislocation length swept out by a pair of kinks decreased as the athermal component of stress increased.","PeriodicalId":103313,"journal":{"name":"Metal Science Journal","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130656605","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}
Pub Date : 1900-01-01DOI: 10.1179/030634568790511525
G. Weatherly
AbstractThe crystallographic substructure of a unidirectionally solidified Al-CuAl2 lamellar eutectic has been investigated by transmission electron microscopy. The two lamellar imperfections, fault lines and terminations, have been studied. The fault lines have been shown to be discrete subgrain boundaries, and at lamellar terminations a high density of nearly parallel dislocations is observed. A model is advanced to explain this dislocation array, based on the low misfit between {111}Al and {211}cuAl2 planes.
{"title":"An Electron-Microscope Investigation of the Lamellar Al-CuAl2 Eutectic","authors":"G. Weatherly","doi":"10.1179/030634568790511525","DOIUrl":"https://doi.org/10.1179/030634568790511525","url":null,"abstract":"AbstractThe crystallographic substructure of a unidirectionally solidified Al-CuAl2 lamellar eutectic has been investigated by transmission electron microscopy. The two lamellar imperfections, fault lines and terminations, have been studied. The fault lines have been shown to be discrete subgrain boundaries, and at lamellar terminations a high density of nearly parallel dislocations is observed. A model is advanced to explain this dislocation array, based on the low misfit between {111}Al and {211}cuAl2 planes.","PeriodicalId":103313,"journal":{"name":"Metal Science Journal","volume":"2013 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130666913","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}
Pub Date : 1900-01-01DOI: 10.1179/030634570790444266
B. L. Jones, C. Sellars
Abstract The creep of copper, copper–10 at.-% nickel and copper–10 at.-% gold has been investigated at 600 and 800° C (875 and 1075 K) for stresses in the range 1000–7500 lbf/in2 (6·9-51·7MN/m2). Subgrain sizes, etch-pit densities, and the contribution of grain-boundary sliding to creep have been determined and dislocation structures examined by thin-foil electron microscopy. The stress exponent of creep rate for copper and copper–10 at.-% nickel is ≃ 5 and that for copper–10 at.-% gold is ≃ 3. Stress-decrement experiments indicate that the effect of nickel is to reduce the rate of the controlling recovery process, whereas the addition of gold changes the controlling process to one of viscous glide of dislocations.
{"title":"The Creep of Copper, Copper–10 at.-% Nickel, and Copper–10 at.-% Gold","authors":"B. L. Jones, C. Sellars","doi":"10.1179/030634570790444266","DOIUrl":"https://doi.org/10.1179/030634570790444266","url":null,"abstract":"Abstract The creep of copper, copper–10 at.-% nickel and copper–10 at.-% gold has been investigated at 600 and 800° C (875 and 1075 K) for stresses in the range 1000–7500 lbf/in2 (6·9-51·7MN/m2). Subgrain sizes, etch-pit densities, and the contribution of grain-boundary sliding to creep have been determined and dislocation structures examined by thin-foil electron microscopy. The stress exponent of creep rate for copper and copper–10 at.-% nickel is ≃ 5 and that for copper–10 at.-% gold is ≃ 3. Stress-decrement experiments indicate that the effect of nickel is to reduce the rate of the controlling recovery process, whereas the addition of gold changes the controlling process to one of viscous glide of dislocations.","PeriodicalId":103313,"journal":{"name":"Metal Science Journal","volume":"303 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124329820","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}
Pub Date : 1900-01-01DOI: 10.1179/030634568790443224
B. Noble, C. Thornton
AbstractA study has been made of the influence of deformation on the resistivity increase that occurs during the artificial ageing of an aluminium-5.12% copper-0.14% cadmium alloy (E. Holmes and B. Noble, J. Inst. Metals, 1967, 95, 106). Small amounts of deformation between solution-treatment and ageing reduced the rise in resistivity. The effect of deformation on the increase was less marked when the material was subsequently annealed at 530°C, or when the deformation followed a short ageing treatment at 180°C. Strain applied simultaneously with ageing also lessened the resistivity rise. The results have been interpreted in terms of copper/cadmium/vacancy clusters. Deformation before ageing limited the number of clusters formed; deformation applied simultaneously with ageing prevented their growth.
本文研究了变形对铝-5.12%铜-0.14%镉合金在人工时效过程中电阻率增加的影响(E. Holmes和B. Noble, J. Inst. Metals, 1967, 95, 106)。固溶处理和时效之间的少量变形降低了电阻率的上升。当材料随后在530°C退火或在180°C进行短暂时效处理时，变形对增加的影响不那么明显。与时效同时施加的应变也减小了电阻率的上升。结果被解释为铜/镉/空位团簇。时效前的变形限制了形成团簇的数量;与时效同时施加的变形阻止了它们的生长。
{"title":"The Effect of Deformation on the Resistivity Anomaly in Al-Cu-Cd Alloys","authors":"B. Noble, C. Thornton","doi":"10.1179/030634568790443224","DOIUrl":"https://doi.org/10.1179/030634568790443224","url":null,"abstract":"AbstractA study has been made of the influence of deformation on the resistivity increase that occurs during the artificial ageing of an aluminium-5.12% copper-0.14% cadmium alloy (E. Holmes and B. Noble, J. Inst. Metals, 1967, 95, 106). Small amounts of deformation between solution-treatment and ageing reduced the rise in resistivity. The effect of deformation on the increase was less marked when the material was subsequently annealed at 530°C, or when the deformation followed a short ageing treatment at 180°C. Strain applied simultaneously with ageing also lessened the resistivity rise. The results have been interpreted in terms of copper/cadmium/vacancy clusters. Deformation before ageing limited the number of clusters formed; deformation applied simultaneously with ageing prevented their growth.","PeriodicalId":103313,"journal":{"name":"Metal Science Journal","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124085557","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}
Pub Date : 1900-01-01DOI: 10.1179/030634568790443477
R. T. Pascoe, C. Newey
AbstractThe deformation behaviour of polycrystalline NiAl of various compositions, and of stoichiometric single crystals with different orientations, has been studied in compression in the temperature range 77–1300° K. All alloys except the aluminium-rich composition (53 at.-% aluminium) were deformable down to 77°K. Plastic deformation of single crystals was strongly anisotropic. All polycrystals and single crystals exhibited the three-stage temperature-dependence of the yield stress typical of b.c.c. alloys. The main effect of non-stoichiometry was to increase the athermal contribution to the yield stress; the strengthening produced by vacancies (aluminium-rich alloys) was greater than that produced by substitutional atoms (nickel-rich alloys).
{"title":"The Mechanical Behaviour of the Intermediate Phase NiAl","authors":"R. T. Pascoe, C. Newey","doi":"10.1179/030634568790443477","DOIUrl":"https://doi.org/10.1179/030634568790443477","url":null,"abstract":"AbstractThe deformation behaviour of polycrystalline NiAl of various compositions, and of stoichiometric single crystals with different orientations, has been studied in compression in the temperature range 77–1300° K. All alloys except the aluminium-rich composition (53 at.-% aluminium) were deformable down to 77°K. Plastic deformation of single crystals was strongly anisotropic. All polycrystals and single crystals exhibited the three-stage temperature-dependence of the yield stress typical of b.c.c. alloys. The main effect of non-stoichiometry was to increase the athermal contribution to the yield stress; the strengthening produced by vacancies (aluminium-rich alloys) was greater than that produced by substitutional atoms (nickel-rich alloys).","PeriodicalId":103313,"journal":{"name":"Metal Science Journal","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126400374","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}
Pub Date : 1900-01-01DOI: 10.1179/030634571790439432
G. A. Hayes, J. Shyne
AbstractThe influence of 20 kHz acoustic oscillations on the recrystallization kinetics of oxygen-free, high-conductivity copper has been investigated. Resonance standing waves with a maximum acoustic stress amplitude of 3.2 × 108 dyn/cm2 (4640lbf/in2) were developed in half-wavelength-long specimens. Ultrasound caused a great increase (30–100 times) in the recrystallization rate, the degree of acoustic enhancement being proportional to the acoustic stress amplitude. Ultrasound did not alter the form of the time-dependence of the nucleation and growth rates for recrystallization, but did decrease the apparent activation energy for recrystallization from 31.5 kcal/mol (132 kJ/mol) (without acoustic energy) to 17.0 kcal/mol (71 kJ/mol).
{"title":"The Influence of Ultrasound on the Kinetics of Recrystallization in Copper","authors":"G. A. Hayes, J. Shyne","doi":"10.1179/030634571790439432","DOIUrl":"https://doi.org/10.1179/030634571790439432","url":null,"abstract":"AbstractThe influence of 20 kHz acoustic oscillations on the recrystallization kinetics of oxygen-free, high-conductivity copper has been investigated. Resonance standing waves with a maximum acoustic stress amplitude of 3.2 × 108 dyn/cm2 (4640lbf/in2) were developed in half-wavelength-long specimens. Ultrasound caused a great increase (30–100 times) in the recrystallization rate, the degree of acoustic enhancement being proportional to the acoustic stress amplitude. Ultrasound did not alter the form of the time-dependence of the nucleation and growth rates for recrystallization, but did decrease the apparent activation energy for recrystallization from 31.5 kcal/mol (132 kJ/mol) (without acoustic energy) to 17.0 kcal/mol (71 kJ/mol).","PeriodicalId":103313,"journal":{"name":"Metal Science Journal","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125664723","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}
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