Fundamental mechanisms affecting friction welding under vacuum.

144 Pages·1.1 MB·en_US

by  Jacoby, Benedicta Renee.

FUNDAMENTAL MECHANISMS AFFECTING FRICTION WELDING
UNDER VACUUM
By
Benedicta Renee Jacoby
B.S. Engineering
University of California, Berkeley (1985)
Submitted to the department of
OCEAN ENGINEERING
In Partial Fulfillment of the Requirements
For the Degrees of
MASTER OF SCIENCE IN NAVAL ARCHITECTURE AND MARINE
ENGINEERING
and
MASTER OF SCIENCE IN MECHANICAL ENGINEERING
at the
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
June, 1991
© Benedicta Renee Jacoby, 1991
The author hereby grainnttss ttoo MM..II..TT.. ppeerrmmiissssiioonn ttoo rreepprroocduce and to distribute
copies of this thesis document in whol)lee or in pan.
IAJ6/6
6.1
FUNDAMENTAL MECHANISMS AFFECTING FRICTION WELDING
UNDER VACUUM
by
Benedicta Renee Jacoby
Submitted to the department of Ocean Engineering
on 10 May 1991 in partial fulfillment of the
requirements for the degrees of S.M. Naval Architecture
and Marine Engineering and S.M. Mechanical Engineering.
ABSTRACT
Inertia welding of 2024-T3 aluminum alloy studs to 2024-T3 plate is investigated at
atmospheric pressure and under vacuum to determine the effects of vacuum, surface
contamination, material, weld force and weld speed on the integrity of the weld. The
vacuum conditions are limited to 10 torr or less due to experimental apparatus. The
fundamental parameters involved in inertia friction welding are investigated here to lead
to the development of a mathematical model for their affects in on-orbit welding in the
A
construction of a space station. bend test is used to determine a sufficient weld.
The special conditions required for on orbit welding are discussed along with a survey
of current welding methods and there feasibility and limitations for space station
construction. Friction welding, as one of only a few joining techniques that is showing
promise for all areas of concern for construction in space : minimal power consumption,
ease of automation, minimal operator skill and lack of toxic by products, is discussed in
detail prior to the experimental presentation.
Thesis Supervisor: Dr. Koichi Masubuchi
Title: Professor of Material Science and Ocean Engineering

ACKNOWLEDGEMENTS
I would like to express my sincere gratitude to the following people:
Dr. Koichi Masubuchi forhis support in this effort and enthusiasm in space station
construction.
Mr. Ravikumar Nagabushanam for his assistance with equipment and knowledge
of the "system".
Mrs. Carolyn Russel of the Marshall Space Flight Center for her assistance in
obtaining suitable materials for testing and her genuine interest.
Lt. Michael Smith for his interest and his willingness to explore new ideas.
My office mates, Dave Klipp and Ralph Soule, for their curiosity, humor and
stimulating conversation.
My
family and friends, for their continuing support, confidence and inspiration.
Lastly, I thank the United States Navy and the Engineering Duty Officer
community for giving me the opportunity and financial support to complete my studies
here at M.I.T.