Recently developed techniques provide totally-confined linear explosive seam welding and produce scarf joint with linear explosive seam welding. Linear ribbon explosives are utilized in making narrow, continuous, airtight joints in variety of aluminum alloys, titanium, copper, brass, and stainless steel

Bement, L. J.

English

NASA Technical Reports Server

NASA TECH BRIEF 
Langley Research Center rNL- A\1`55A 
L h.^_ 
ia 
June 1973
	
B73-10180 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
New Explosive Seam Welding Concepts 
Steel Tube
0.030 Inch (0.076 cm)
Wall
IlinDon xpIosive 
Figure 1. Setup for Explosive Weld to Confine 
Explosive Detonation Products 
Techniques have recently been developed to provide 
totally-confined linear explosive seam welding and to 
produce a scarf joint with linear explosive seam welding. 
These techniques are extensions of the technology 
described earlier (see Notes) in which linear ribbon 
explosives have been utilized in making narrow, con-
tinuous, airtight joints in a variety of aluminum alloys, 
titanium, copper, brass, and stainless steel.
The totally confined explosive seam welding concept 
uses a flattened steel tube, as shown in Figure 1. The 
ribbon explosive is placed inside the tube against the 
tube wall in contact with the plate to be welded. On 
detonation of the explosive the pressure is transferred 
through the wall to produce a normal welded joint. 
The pressure front propagating upward is first atten-
uated and diffused by the silicone rubber and then 
confined by the tube in its expansion upward. Totally 
confined explosive seam welding eliminates the sound, 
flame, smoke, lead sheathing, and masking tape that 
are products of the normal explosive seam welding 
technique. This confinement technique permits explosive 
welding in areas sensitive to contamination or in close 
proximity to personnel and is being considered for use 
in the space station docking system. The confinement 
tubes would be placed inside and outside the concentric 
cylinders to be welded and, on simultaneous firing of 
the two explosive ribbons, would form an airtight, 
continuous joint. 
The scarf joint (see Figure 2) permits splicing of 
sheet stock in thicknesses to 0.090 inch (0.229 cm) 
without the addition of material and produces joints 
Standoff
	
Explosive 
Figure 2. Setup For and Resultant Scarf Joint
(continued overleaf) 
	
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https://ntrs.nasa.gov/search.jsp?R=19730000180 2020-03-17T07:10:22+00:00Z
that exhibit strength up to that of the parent metal. 
The plates to be joined are placed in parallel planes, 
separated by approximately 0.015 inch (0.038 cm). 
The longitudinal axes of the ribbon explosive placed 
outside the plates to be welded are misaligned to 
produce forces that are not directly opposing. On 
simultaneous detonation of the two ribbon explosives, 
the plates are bent into axial alignment and welded in 
the same operation. This joint is particularly suited for 
longitudinal tankage and large diameter pipe joints 
which require high strength. Conventional joining tech-
niques require the addition of material in the joint area 
to accomplish parent metal strength following the 
joining. 
Notes: 
1. Basic explosive welding techniques are described and 
illustrated in NASA Tech Brief B72 . 10002 and 
Technical Support Package TSP72-10002.
2. Requests for further information should be directed 
to:
Technology Utilization Officer 
Langley Research Center 
Mail Stop 139A 
Hampton, Virginia 23665 
Reference: B73-10180 
Patent status: 
This invention is owned by NASA, and a patent 
application has been filed. Inquiries concerning non-
exclusive or exclusive license for its commercial develop-
ment should be addressed to: 
Patent Counsel 
Langley Research Center 
Mail Stop 456 
Hampton, Virginia 23665 
Source: Laurence J. Bement 
Langley Research Center 
(LAR-1 1211)
. 
is 
B73-10180	 Category 04


New explosive seam welding concepts

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