Chemical vapor deposition of thoriated tungsten protective cups Page: 32 of 45
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 tensile properties of vapor deposited thoriated tungsten tubing were determined
at 20000C and 24000C. Specially prepared 0.250 inch inside diameter tubes 6 inches long
were made using a deposition system similar to that developed for metallic cups in order to
attain an identical as-heat-treated microstructure. The specimen shoulder walls were 0.050
inch thick, and the reduced wall section was 0.020 inch.
The tensile testing was conducted at Southern Research Institute in a helium
atmosphere using a gas-bearing apparatus for assuring uniaxial loading.
The test was conducted in a tungsten resistance heating furnace with a loading rate
of 0.050 in/in/min strain rate. The ultimate tensile strength decreased from 10,500 psi at 20000C
to 8,100 psi at 24000C; the 0.2 percent off set yield strength decreased from 8,700 at 20000C
to 6,700 at 24000C; and the elastic modulus decreased from 8. 6 x 106 to 6.5 x 106 psi.
Room temperature and 14000C tensile data were derived from compression ring tests
of specimens sliced from stress relieved cups. Values were derived by compressing the rings
to failure between flats and applying a calibration constant derived from ring bursting stress
calculations. The ultimate strength at 14000C was 50,600 psi, and the average of ten tests
at room temperature was 127,200 psi. The values ranged from 99,000 psi to 155,000 psi.
Figure 14 shows the dramatic improvement in elevated temperature tensile strength
of CVD thoriated tungsten as compared to pure vapor deposited tungsten.
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.
Blay, J.S. Chemical vapor deposition of thoriated tungsten protective cups, report, January 1, 1968; Pittsburgh, Pennsylvania. (https://digital.library.unt.edu/ark:/67531/metadc1026564/m1/32/: accessed March 22, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.