Hello Bob Williams If you temper titanium, there is no need to quench.
In that way it works like silver, and quenching does not effect the
crystal structure again. Low carats of gold (14K and lower) have
precipitation hardening at temperature around 250 degrees Celsius. and
therefore you have to go very fast trough this face. this can only be
done by quenching. But start after there is now glow and then quench
in water. or better alcohol. this cool slower and gives lower internal
tensions. For Titanium, ,jewellers do not need a good crystal
structure. we are not building airplanes. The material strength is
enough for most purposes. So the correct way of heating and cooling
down is not important.
For Dan, you are also correct to say that non alloyed titanium
(grade 1 or 2) can only be hardened by deformation. The purer the
titanium the softer and more ductile is stays and is. But if you take
highly alloyed titanium you need special heat treatments and these
alloys can also be hardened. These alloys are nothing for us
jewellers . there are alloys were it is impossible to drill a hole
it. the tensile strengths can go up as high as medium hardened tool
steel. However the stiffness of titanium as 3 times lower as steel, so
the flexibility stays.