Arch-shaped conductors fabricated from flat strips of beryllium oxide dispersion-strengthened copper alloy serve as flexible electrical connectors capable of operating in 1000 deg F temperature range, under vacuum conditions for periods of 10,000 hours or more without failure

Koutnik, E. A.

Mueller, L. A.

Snider, W. E.

English

NASA Technical Reports Server

October 1970	 Brief 70-10569 
NASA TECH BRIEF 
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 Clearinghouse for Federal Scientific and Technical 
Information, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Division, NASA, Code UT, Washington, D.C. 20546. 
Flexible Electrical Conductors for High-Temperature Switchgear 
0, 
I 
The problem: 
To develop a flexible electrical connector capable 
of operating in the 1000°F temperature range, under 
vacuum conditions for long periods (10,000 hours or 
more) without failure. The oxygen-free high-conduc-
tivity copper conventionally used in connectors oper-
ating at ambient temperatures lacks the necessary 
strength to endure repeated flexing at the required 
operating conditions. A material was needed which not 
only met the operating conditions, but also retained
high electrical conductivity. Configuration of the 
connector required that one end be fixed and the other 
end, approximately one inch away, be fastened to a 
contact which moved a minimum of 0.25 inch between 
its open and closed positions. 
The solution: 
Arch-shaped conductors fabricated from flat strips 
of commercially available beryllium oxide dispersion-
strengthened copper alloy (see fig.). 
How it's done: 
A review of available materials identified beryllium 
oxide dispersion-strengthened copper as a material 
having all of the necessary properties. However, 
beryllium oxide dispersion-strengthened copper is 
conventionally fabricated only in wire and rod form. 
It was not possible to manufacture the connector from 
this material in wire or rod form with a stress level 
low enough to ensure the required durability with 
repeated flexing, and a cross-sectional area large 
enough to attain the required electrical conductivity. 
A manufacturer of beryllium oxide dispersion-
strengthened copper successfully rolled the wire form 
into flat strips 0.006-inch thick. After determining 
the physical properties of this flat material, eight 
rolled strips, 0.50-inch wide, were cut, formed, and 
then staked into an arch shape. This design provided 
both a low stress level and sufficient cross-sectional 
area. The arch-shaped connectors were tested for 
1000 hours at temperatures from 500°F to 1200°F 
in a vacuum of 1 x 10 torr. During the test, the 
connectors were flexed 1000 times, i.e., one end was 
fixed and the other end was moved vertically 0.25 inch. 
In a later test at 1000°F and a vacuum of I >< 106 
torr, the conductor assembly carried over 1800 am-
peres while flexing. The arch-shaped beryllium oxide 
(continued oserleal) 
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dispersion-strengthened copper connectors performed 
satisfactorily without noticeable deterioration. Tensile 
strength of the strip material was reduced from 82,000 
psi to 71,500 psi during the first 500 hours of a room 
temperature test, and only negligibly thereafter. 
Notes: 
1. These flexible electrical conductors could re-
place conventional electrical braiding and leads 
operating at high temperatures. In strip form, the 
material could be utilized for electrical conductors 
requiring high strength at temperatures to 1800°F. 
2. The following documentation is available from: 
Clearinghouse for Federal Scientific 
and Technical Information 
Springfield, Virginia 22151 
Single document price $3.00 
(or microfiche $0.65)
Reference: 
NASA-TM-X-1986 (N70-23527), Flexible 
Electrical Conductors for High-Temperature 
Switchgear 
Technical questions may be directed to:

Technology Utilization Officer 
Lewis Research Center 
21000 Brookpark Road 
Cleveland, Ohio 44135 
Reference: B70-10569 
Patent status: 
No patent action is contemplated by NASA. 
Source: L.A. Mueller, W.E. Snider and 
E.A. Koutnik 
Lewis Research Center 
(LEW-1 1109) 
Brief 70-10569	 Category 01,04


Flexible electrical conductors for high-temperature switchgear

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