Mechanical alloying (MA) was employed to produce supersaturated solid solutions of Fe1-xCux,which is virtually immiscible under an equilibrium condition at ambjent temperature. The X-ray diffraction results show that ...Mechanical alloying (MA) was employed to produce supersaturated solid solutions of Fe1-xCux,which is virtually immiscible under an equilibrium condition at ambjent temperature. The X-ray diffraction results show that the solutions formed in the concentration ranges of x≤0.1 5 and x≥0.40 are of bcc structure of iron and fcc structure of copper. respectively. For the region in between.however, the alloy obtained is a mixture of bcc plus fcc phases. The Mossbauer spectrum of the solid solution of a single phase could be fitted by two sub-spectra with hyperfine magnetic fields of 200 and 250 kOe. respectively. suggesting that there must exist two forms of coordination in the solution. While to fit the spectrum for the solution with mixed structu re. three Sub-spectra. including a spectrum of α-Fe, should be used. The variation of the Mossbauer spectra of Fe60Cu40 with milling time as well as annealing temperature was systematically studied. This may be ascribed to the changes of the number of nearest neighboring atoms of iron in the processes of formation and decomposition of the solid solution during milling and annealing展开更多
Strengthening due to precipitation of Cu in the a-Fe matrix is an important phenomenon utilized in the design of HSLA steels. In the present work, the microstructure of supersaturated solid solution in Fe-1.18%Cu bina...Strengthening due to precipitation of Cu in the a-Fe matrix is an important phenomenon utilized in the design of HSLA steels. In the present work, the microstructure of supersaturated solid solution in Fe-1.18%Cu binary alloy was investigated by means of high resolution electron microscopy. The results indicated that the solid solution was heterogeneous, there were lots of Cu atom clusters, which consisted of diffractive stripe microstructure similar to twin crystal. Orientation deviation was observed between two （110）o planes in diffractive stripes, which results in light and shade contrast. Furthermore, formation mechanisms of the nanometre stripe microstructure were discussed in terms of the interaction of Cu and Fe atoms in the Fe-Cu binary alloys.展开更多
The mechanical properties of super saturated solid solution Fe60Cu40 alloy has been investigated using compression test. The results show that the grain precipitation and phase transformation occurs during compressive...The mechanical properties of super saturated solid solution Fe60Cu40 alloy has been investigated using compression test. The results show that the grain precipitation and phase transformation occurs during compressive deformation resulting in large work-hardening ability, high strength and large ductility. Our results demonstrate that this novel architecture offers a design pathway towards a new generation of strong materials with large ductility.展开更多
Mechanical alloying was employed to produce super—saturated solution of Fe_1-xCu_x ,which is virtually immiscible under an equilibrium condition at ambient temperature.XRD results show that the solutions formed in th...Mechanical alloying was employed to produce super—saturated solution of Fe_1-xCu_x ,which is virtually immiscible under an equilibrium condition at ambient temperature.XRD results show that the solutions formed in the concentration ranges of x≤O.15 and x≥0.40 are of bee structure of x-Fe and fee structure of Cu,respectively.For the region in between (0.15<x<0.40),however,the alloy obtained is a mixture of bee plus fee phases.DSC traces indicate that there exist two broad exothermal peaks for all samples,the first peak responds to the releasing of stored strain and the second to the decomposition of solid solutions.展开更多
文摘Mechanical alloying (MA) was employed to produce supersaturated solid solutions of Fe1-xCux,which is virtually immiscible under an equilibrium condition at ambjent temperature. The X-ray diffraction results show that the solutions formed in the concentration ranges of x≤0.1 5 and x≥0.40 are of bcc structure of iron and fcc structure of copper. respectively. For the region in between.however, the alloy obtained is a mixture of bcc plus fcc phases. The Mossbauer spectrum of the solid solution of a single phase could be fitted by two sub-spectra with hyperfine magnetic fields of 200 and 250 kOe. respectively. suggesting that there must exist two forms of coordination in the solution. While to fit the spectrum for the solution with mixed structu re. three Sub-spectra. including a spectrum of α-Fe, should be used. The variation of the Mossbauer spectra of Fe60Cu40 with milling time as well as annealing temperature was systematically studied. This may be ascribed to the changes of the number of nearest neighboring atoms of iron in the processes of formation and decomposition of the solid solution during milling and annealing
基金Item Sponsored by National Natural Science Foundation of China (50361001)
文摘Strengthening due to precipitation of Cu in the a-Fe matrix is an important phenomenon utilized in the design of HSLA steels. In the present work, the microstructure of supersaturated solid solution in Fe-1.18%Cu binary alloy was investigated by means of high resolution electron microscopy. The results indicated that the solid solution was heterogeneous, there were lots of Cu atom clusters, which consisted of diffractive stripe microstructure similar to twin crystal. Orientation deviation was observed between two （110）o planes in diffractive stripes, which results in light and shade contrast. Furthermore, formation mechanisms of the nanometre stripe microstructure were discussed in terms of the interaction of Cu and Fe atoms in the Fe-Cu binary alloys.
文摘The mechanical properties of super saturated solid solution Fe60Cu40 alloy has been investigated using compression test. The results show that the grain precipitation and phase transformation occurs during compressive deformation resulting in large work-hardening ability, high strength and large ductility. Our results demonstrate that this novel architecture offers a design pathway towards a new generation of strong materials with large ductility.
文摘Mechanical alloying was employed to produce super—saturated solution of Fe_1-xCu_x ,which is virtually immiscible under an equilibrium condition at ambient temperature.XRD results show that the solutions formed in the concentration ranges of x≤O.15 and x≥0.40 are of bee structure of x-Fe and fee structure of Cu,respectively.For the region in between (0.15<x<0.40),however,the alloy obtained is a mixture of bee plus fee phases.DSC traces indicate that there exist two broad exothermal peaks for all samples,the first peak responds to the releasing of stored strain and the second to the decomposition of solid solutions.
