Clarence "Kelly" Johnson quotes about the SR-71 Titanium and problems during it's development.
"The tough titanium actually is a very sensitive material to handle."
"Titanium
is such a ridged material that it cannot be shoved into place - as can
some other metals and therefore cut to less-exact tolerances."
"It must be tooled to fit. "This exact tooling is very expensive-"
"Special tools were required, a drill would be totally destroyed after about 17 rivet holes."
"We were paying $119 per foot for titanium extrusions, and it was costing us $19 per inch to machine them".
(That's early 1960's dollars)Kelly Johnson's narration of the Blackbird titanium parts fabrication process.
"Hot sizing process at ADP is used to form close tolerance parts from titanium sheet metal.
A furnace is used to preheat steel dies to 1400 degrees F.
The hot die is then move to a hot sizing press where they are then kept hot by electric heaters.
The
hydraulically operated hot sizing press applies pressure to the
titanium parts holding them at a constant temperature and pressure for a
processing period of 15 minutes.
The parts are then removed from the dies and allowed to cool.
Parts are then pickled and cleaned and then readied for assembly.
Spot welding machines with close current controls are use to assemble many of the Blackbird airframe components.
This equipment is of special design and suitable only for a sophisticated titanium alloy."
~~~~~~~~~
Working
titanium requires special conditions, exact tolerances, harder higher
quality tools and cutters. When forming, it must be done red hot using
fixtures and dies. Extreme care must be taken not to exceed temperatures
that would allow oxygen to be absorbed thus ruining the material.
During welding all oxygen must be eliminated by the use of an expensive
inert argon shielding gas. Ideally, welds must be made inside of
specially made protective welding chambers, a very expensive process.
Titanium
is an amazing material. It is "bio-inert" making it useful for surgical
implants as well as jewelry. Titanium displays many variations in
appearance from a highly reflective, deep silvery smokey luster to a
wide variety of rainbow coloration's. As it ages it it takes on
wonderful patina and It can easily be polished to it's original luster.
This
is actually titanium's way of preserving itself by instantly developing
a protective layer of oxides. This makes the titanium nearly
indestructible against acids, alkali's, and salts.
It is very
lightweight and warms to the body's temperature quickly, making it very
comfortable as jewelry. Some people report that it emits homeopathic
properties similar to healing crystals. Others say it gives them a
feeling of energy and balance. If there are any such metaphysical
properties it may be related to the titanium's molecule. It has the
ability to retain its crystal structure with continuous heating and
cooling.
Who knows what mysteries were discovered by the world's
top scientist, engineers, and alchemists in the back rooms and secret
laboratories of Skunk Works and Area 51. Just holding a piece of this
material in your hand, you will see that it feels like nothing else. It
is evident that something very special happened during the development
of the Blackbirds and that there were reasons why the program was kept
secret for so long, more secret than the Manhattan Project. You may
wonder why the USAF and NASA spent millions of dollars destroying every
last piece that was held in high security storage for so many years.