Martin H. Eastburn wrote in message
...
Explosive welding.
Simple as that.
Martin

N_Cook wrote:
Interesting , but no further forward. Looks as though these froststats
will
remain froststats. Surprising ping and bounce as much as six inches on
change of state, the loud ping is somewhat damped when inside the
casing.
Need freezer spray to change the state of these discs (hysteresis and
all
that). When back to body temp I tried grinding a spot in the centre of
the
concave side, no change in set temp. Tried 4 diametrical marks on the
concave side , no change in response. Tried deeper but small 8 cuts just
on
the perphery, now no ping but slowly migrates from one state to the
other ,
still requiring freezer spray. I wonder how they "weld" these 2
materials
together.



I would have thought friction welding, probably many to a spin and then
press cut to small discs