Investigation of aluminum alloy welds reveals that the combinations of metallic elements with hydrogen are not capable of producing weld porosity themselves, rather they tend to increase the amount of porosity only in the presence of arc contamination by water vapor

Cheever, D. L.

Martin, D. C.

Mishler, H. W.

Monroe, R. E.

English

NASA Technical Reports Server

June 1968	 Brief 68-10192 
NASA TECH BRIEF 
NASA Tech Briefs are issued to summarize specific innovations derived from the U.S. space program, 
to encourage their commercial application. Copies are available to the public at 15 cents each 
from the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Welding of Commercial Base Plates Is Investigated 
.
An investigation has been made concerning the 
effects of the metallic element composition and the 
internal hydrogen content of commercial 2000 series 
aluminum alloys upon welds in these materials. Welds 
were made bead-on-plate, using base plate thicknesses 
of 1/4 and 3/4 inch. The inert gas welding atmosphere 
was deliberately contaminated with water vapor at a 
dewpoint of about 0°F to produce a "baseline" 
amount of weld porosity. A limited number of welds 
were made with the addition of 4043 filler wire to 
2014-T651 plate and 2319 filler wire to 2219-T87 plate. 
Welds were also made with the welding atmosphere at 
a dewpoint of about —40 0 F. Use of a radioactive 
isotope as a means of identifying hydrogen in the weld 
was evaluated during the investigation. 
Welds were made in the horizontal position using 
precisely controlled equipment and finely calibrated 
instrumentation. Welds were examined by radio-
graphic and sectioning techniques. Amount of poros-
ity was the major item of interest and was quantita-
tively determined using point counting techniques on 
lightly etched transverse weld sections. Amount of 
porosity was related by statistical analysis to the com-
position of the parent metal. 
The investigation demonstrated that the combina-
tions of metallic elements with hydrogen were not 
capable of producing weld porosity themselves, rather 
they tended to increase the amount of porosity only
in the presence of arc contamination by water vapor, 
a common troublemaker in welding. Hydrogen con-
tent of the welds was found to be directly related to 
alloy composition. Increased numbers of intermetal-
lic particles did not seem to have any effect. Pores 
occurred preferentially at solute-depleted regions 
while nucleation and growth of pores were observed to 
be nonuniform. Welds of 2014 alloy fractured during 
test along the fusion zone boundary while the 2219 
alloy welds fractured diagonally across the weld. 
Where gradual thermal gradients existed, base metal 
porosity occurred near the fusion zone. 
Note: 
Inquiries concerning this investigation may be di-
rected to:
Technology Utilization Officer 
Marshall Space Flight Center 
Huntsville, Alabama 35812 
Reference: B68-10192 
Patent status: 
No patent action is contemplated by NASA. 
Source: D. L. Cheever, H. W. Mishler, 
R. E. Monroe, and D. C. Martin 
of Battelle Memorial Institute 
under contract to 
Marshall Space Flight Center 
(M FS-l3649) 
Category 03 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19680000192 2020-03-12T05:30:28+00:00Z


Welding of commercial base plates is investigated

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