Seven Years of Uranium Alloy Development at Weldon Spring, 1959/1966. Page: 35 of 47
This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to Digital Library by the UNT Libraries Government Documents Department.
The following text was automatically extracted from the image on this page using optical character recognition software:
The abandonment of the dingot process for direct fabrication to fuel cores
eliminated the circumstance calling for an alpha phase vacuum anneal to control
the hydrogen content. Without this incentive, there'has not appeared to be
sufficient benefit from the polygonization effect to justify the cost of the
extra heat treatment. Without active interest, therefore, from the reactor
sites, this aspect of grain size control has not been:-pursued further.
MECHANICAL AND PHYSICAL PROPERTIES OF URANIUM ALLOYS
A number of limited test programs were undertaken to explore various physical
and mechanical properties of uranium alloys as.support to the programs at, the
reactor sites devoted to a search for fuel that would resist higher tempera-
tures of and prolonged exposures to irradiation. Some of these have not been
carried to a logical conclusion largely because of lack of manpower to perform
the necessary bulk of testing.
Hot Hardness Testing (Creep Penetration Tests)
In the early stages of the search originating at Savannah River for an alloy to
provide an improved fuel element, the possibility was entertained that creep
strength of the alloys at high alpha temperatures might play a critical role in
determining the degree to which a-given alloy might be resistant to swelling
during irradiation. Since high temperature creep testing is a laborious and
expensive experimental procedure, it was proposed that a correlation be sought
with hot hardness. In the reporting of these tests, this property was referred
to as "creep penetration."30,5,58
A considerable experimental effort devoted to this program at Savannah River
was supplemented at Weldon Spring by a series of tests designed to appraise and
improve the test procedure and to explore its validity. The parameters which
were studied included the effects of load, time, alloy content, and heat
As might be expected, it was promptly found that close temperature control was
essential since hot hardness varies sensitively as the temperature rises. It
was, also demonstrated that loading with a lever was considerably superior to
spring loading. Errors were encountered with spring loading that were two
orders of magnitude greater than the small (+ 2 pound) error derived from a
lever in the 400-800 pound application range.
The indentations recorded were shown to bear an exponential relationship to the
applied load regardless of temperature, and an equation could readily be
determined to express the behavior for any given alloy at any given temperature.
As also might be expected, the type and quantity of alloy addition proved to be
a most sensitive parameter in determining the resistance to flow under the
indentor. Alloys containing 1000 ppm molybdenum were particularly superior in
this respect. The resistance to indentation appeared, however, to be related
to' the amount of alloy in solid solution and not to the presence of the fine
precipitate that is postulated to improve in-reactor dimensional stability.
. . . . . . .
Here’s what’s next.
This report can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Report.
Fellows, J. A. Seven Years of Uranium Alloy Development at Weldon Spring, 1959/1966., report, January 1, 1966; Weldon Spring, Missouri. (https://digital.library.unt.edu/ark:/67531/metadc1033773/m1/35/: accessed March 20, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.