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Title: TRANSFORMATION KINETICS OF PLUTONIUM. PART III

Abstract

Isothermal reaction curves and T-T-T curves showing the effect of different variables on the beta-alpha transformations in plutonium are presented. Impurity content, stresses, beta heat-treating time and temperature, hydrostatic pressing, specimen size, and thermal cycling influenced the kinetics of the beta- alpha transformation. Decreasing the impurlty content increased the rate of transformation. High tensile stress retarded the beta-alpha transformation. Increasing the beta heat-treating time and temperature markedly decreased the rate of transformation. Hydrostatic pressing at 90,000 psi accelerated the beta- alpha transformation under pressure but decreased any subsequent beta-alpha transformations by as much as two orders of magnitude. Specimen size had no effect on the start of the transformation but increasing the specimen size from 0.010 to 0.37 inch decreased the rate of completion of transformation several orders of magnitude. Thermal cycling less than 15 cycles did not affect the rate of transformation. The density of high purity plutonium during hydrostatic pressing at l80 deg C and cooling under pressure increased from 19.60 to 19.65 g/ cm/sup 3/to 19.70 to 19.75 g/cm/sup 3/. This increase was shown to be attributed to decreasing the volume of microcracks rather than transformation of any metastable beta phase. A T-T-T curve of the alpha-betamore » transformation is given which shows the start of the transformation is 16 hours at 116.5 deg C with the rate decreasing extremely rapidly with decreasing temperature. The times for the start and completion of the transformation were significantly shorter than the early work reported. The faster rate was attributed to less impurities, The gamma-beta-alpha and alpha-beta-gamma transformations are discussed also. Isothermal reaction curves and T-T-T curves for these transformation are included. (auth)« less

Authors:
Publication Date:
Research Org.:
General Electric Co. Hanford Atomic Products Operation, Richland, Wash.
OSTI Identifier:
4819065
Report Number(s):
HW-70859
NSA Number:
NSA-16-007886
DOE Contract Number:  
AT(45-1)-1350
Resource Type:
Technical Report
Resource Relation:
Other Information: Orig. Receipt Date: 31-DEC-62
Country of Publication:
United States
Language:
English
Subject:
METALS, CERAMICS, AND OTHER MATERIALS; ALLOTROPY; CRACKS; DIAGRAMS; HEAT TREATMENTS; IMPURITIES; PHASE TRANSFORMATION; PLUTONIUM; PLUTONIUM-ALPHA; PLUTONIUM-BETA; PLUTONIUM-GAMMA; PRESSURE; REACTION KINETICS; STRESSES; THERMAL CYCLING; VOLUME

Citation Formats

Nelson, R.D. TRANSFORMATION KINETICS OF PLUTONIUM. PART III. United States: N. p., 1961. Web. doi:10.2172/4819065.
Nelson, R.D. TRANSFORMATION KINETICS OF PLUTONIUM. PART III. United States. doi:10.2172/4819065.
Nelson, R.D. Fri . "TRANSFORMATION KINETICS OF PLUTONIUM. PART III". United States. doi:10.2172/4819065. https://www.osti.gov/servlets/purl/4819065.
@article{osti_4819065,
title = {TRANSFORMATION KINETICS OF PLUTONIUM. PART III},
author = {Nelson, R.D.},
abstractNote = {Isothermal reaction curves and T-T-T curves showing the effect of different variables on the beta-alpha transformations in plutonium are presented. Impurity content, stresses, beta heat-treating time and temperature, hydrostatic pressing, specimen size, and thermal cycling influenced the kinetics of the beta- alpha transformation. Decreasing the impurlty content increased the rate of transformation. High tensile stress retarded the beta-alpha transformation. Increasing the beta heat-treating time and temperature markedly decreased the rate of transformation. Hydrostatic pressing at 90,000 psi accelerated the beta- alpha transformation under pressure but decreased any subsequent beta-alpha transformations by as much as two orders of magnitude. Specimen size had no effect on the start of the transformation but increasing the specimen size from 0.010 to 0.37 inch decreased the rate of completion of transformation several orders of magnitude. Thermal cycling less than 15 cycles did not affect the rate of transformation. The density of high purity plutonium during hydrostatic pressing at l80 deg C and cooling under pressure increased from 19.60 to 19.65 g/ cm/sup 3/to 19.70 to 19.75 g/cm/sup 3/. This increase was shown to be attributed to decreasing the volume of microcracks rather than transformation of any metastable beta phase. A T-T-T curve of the alpha-beta transformation is given which shows the start of the transformation is 16 hours at 116.5 deg C with the rate decreasing extremely rapidly with decreasing temperature. The times for the start and completion of the transformation were significantly shorter than the early work reported. The faster rate was attributed to less impurities, The gamma-beta-alpha and alpha-beta-gamma transformations are discussed also. Isothermal reaction curves and T-T-T curves for these transformation are included. (auth)},
doi = {10.2172/4819065},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1961},
month = {12}
}