Abstract
The intermetallic precipitates in Zircaloy-2 are mainly Zr(Cr,Fe){sub 2} and Zr{sub 2}(Ni,Fe). Zircaloy-4 only has the former unless the nickel impurity level is high. These precipitates are based on the hcp ZrCr{sub 2} Laves phase and bct Zr{sub 2}Ni Zintl phase with Fe substituting for Cr and Ni in proportions that depend on the alloy composition. Their structure, composition and morphology are determined by the metallurgical history and can be changed by n eutron irradiation. Zr(Cr,Fe){sub 2} precipitates irradiated at 580 K are depleted in Fe and to a lesser extent Cr. Depletion below the stoichiometric value is coincident with transformation from a crystalline to an amorphous structure. The transformation starts at the surface of the precipitate and advances inwards with increasing fluence. No structural change has been observed in Zr{sub 2}(Ni,Fe) precipitates irradiated at 580 or 675 K. At irradiation temperatures {>=} 675 K there is solute depletion and dissolution of Zr(Cr,Fe){sub 2} precipitates but no crystalline-amorphous transformation has been observed. There is a distinct observable change in precipitate morphology with the formation of Fe rich precipitates at grain boundaries and in the matrix. Both the Zr(Cr,Fe){sub 2} and Zr{sub 2}(Ni,Fe) precipitates irradiated at 350 K undergo complete amorphous
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Citation Formats
Griffiths, M, Gilbert, R W, and Cheadle, B A.
Formation, growth and decomposition of precipitates in Zircaloy-2 and -4.
Canada: N. p.,
1985.
Web.
Griffiths, M, Gilbert, R W, & Cheadle, B A.
Formation, growth and decomposition of precipitates in Zircaloy-2 and -4.
Canada.
Griffiths, M, Gilbert, R W, and Cheadle, B A.
1985.
"Formation, growth and decomposition of precipitates in Zircaloy-2 and -4."
Canada.
@misc{etde_10139657,
title = {Formation, growth and decomposition of precipitates in Zircaloy-2 and -4}
author = {Griffiths, M, Gilbert, R W, and Cheadle, B A}
abstractNote = {The intermetallic precipitates in Zircaloy-2 are mainly Zr(Cr,Fe){sub 2} and Zr{sub 2}(Ni,Fe). Zircaloy-4 only has the former unless the nickel impurity level is high. These precipitates are based on the hcp ZrCr{sub 2} Laves phase and bct Zr{sub 2}Ni Zintl phase with Fe substituting for Cr and Ni in proportions that depend on the alloy composition. Their structure, composition and morphology are determined by the metallurgical history and can be changed by n eutron irradiation. Zr(Cr,Fe){sub 2} precipitates irradiated at 580 K are depleted in Fe and to a lesser extent Cr. Depletion below the stoichiometric value is coincident with transformation from a crystalline to an amorphous structure. The transformation starts at the surface of the precipitate and advances inwards with increasing fluence. No structural change has been observed in Zr{sub 2}(Ni,Fe) precipitates irradiated at 580 or 675 K. At irradiation temperatures {>=} 675 K there is solute depletion and dissolution of Zr(Cr,Fe){sub 2} precipitates but no crystalline-amorphous transformation has been observed. There is a distinct observable change in precipitate morphology with the formation of Fe rich precipitates at grain boundaries and in the matrix. Both the Zr(Cr,Fe){sub 2} and Zr{sub 2}(Ni,Fe) precipitates irradiated at 350 K undergo complete amorphous transformation although solute depletion has not been observed.}
place = {Canada}
year = {1985}
month = {Sep}
}
title = {Formation, growth and decomposition of precipitates in Zircaloy-2 and -4}
author = {Griffiths, M, Gilbert, R W, and Cheadle, B A}
abstractNote = {The intermetallic precipitates in Zircaloy-2 are mainly Zr(Cr,Fe){sub 2} and Zr{sub 2}(Ni,Fe). Zircaloy-4 only has the former unless the nickel impurity level is high. These precipitates are based on the hcp ZrCr{sub 2} Laves phase and bct Zr{sub 2}Ni Zintl phase with Fe substituting for Cr and Ni in proportions that depend on the alloy composition. Their structure, composition and morphology are determined by the metallurgical history and can be changed by n eutron irradiation. Zr(Cr,Fe){sub 2} precipitates irradiated at 580 K are depleted in Fe and to a lesser extent Cr. Depletion below the stoichiometric value is coincident with transformation from a crystalline to an amorphous structure. The transformation starts at the surface of the precipitate and advances inwards with increasing fluence. No structural change has been observed in Zr{sub 2}(Ni,Fe) precipitates irradiated at 580 or 675 K. At irradiation temperatures {>=} 675 K there is solute depletion and dissolution of Zr(Cr,Fe){sub 2} precipitates but no crystalline-amorphous transformation has been observed. There is a distinct observable change in precipitate morphology with the formation of Fe rich precipitates at grain boundaries and in the matrix. Both the Zr(Cr,Fe){sub 2} and Zr{sub 2}(Ni,Fe) precipitates irradiated at 350 K undergo complete amorphous transformation although solute depletion has not been observed.}
place = {Canada}
year = {1985}
month = {Sep}
}