Hello,
I need some clarifications about the mounting process. When we do hot mounting in the Buehler Machine for example, the sample surrounded by the polymer goes through a cycle: pre-heating, heating then cooling.
Does this process has an effect on the microstrure of the steel specimen for example ?
Thank you in advance.
It depends on the microstructure and carbon content of steel. Hot mounting temperature (about 180 degree) can essentially temper medium/high carbon containing martensitic structure. At 180C, some of the dislocations may annihilate; some transitional carbides (epsilon, Hagg carbides) may form as well. However, if your steel carbon content is
Thank you all foryour answers. In my case, i use the Bakelite as a resin in mounting, and a Simplimet 3000 Buehler machine. The specimens that i study are steel and aluminum. And i don't see any change in the structure when seeing them in light microscope .. i was wondering how no change could happen even if the sample is heated at an elevated temperature ... But it seems that it is due to the microstructure ...
At 180C (hot mounting process temperature), steel microstructure changes in nano or micrometer level. You can not reveal them in optical microscope; either you need a high-resolution SEM or TEM to observe the changes. As I said, hot mounting temperature has insignificant (or negligible) effect on steel microstructural changes. I can not make any comments on Aluminum. You can do some literature search on heat treatment of steel or aluminum. Best of luck
For human body,
maybe 180 deg C is considered as "elevated temperature"
but not for Steel, it is considered 'cold'.
According to Fe-C phase diagram,
relative from room temp., the 'nearest' temperature
for equilibrium phase transformation to happen is at/around 727 deg C.
And any working applied below Recrystallization Temp,
(i.e. +- 400 deg C for Steel, and
+- 250 deg C for Aluminum),
is still considered "Cold Working".
Thus 'hot' mounting at 180 deg C,
with 'insignificant' loading from the machine
will not give any noticeable effect on the specimen.
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