Introduction of cryo-rolling:
Cryo-rolling is a potential technique to improve a strength and hardness of the material.it is a very effective and reliable process to get desired mechanical properties.
Process :In cryo-rolling we dipped the material in liquid nitrogen (-190*c) and hold it for a 30 minute or one hour (depends on our requirement) and then doing a rolling process between two rollers.
After checking the micro-structure of the material then we can get a ultra-fine grain structure (grain size:less than 100nm) which have a more strength and hardness compared to cold rolling process.By concept of strengthening mechanism and holl-patch equation (s0 = s + k d-1/2),if grain size is lower then strength in increases
After cryo-rolling process we can also do the tensile and hardness test by tensometer and hardness tester respectively.By doing a test we can achieve a higher strength and hardness compared to room temperature rolling.
Advantages of Cryo-rolling:
1.By cryo-rolling we can achieve a ultra-fine grain structure which improves a strength and ductility compared to cold rolling process
2.handling of the material is easy in cryo-rolling compared to hot rolling precess
3.If subsequently we are doing a annealing process after cryo-rolling then we can get a desirable ductility
4.cryo-rolling require a less plastic deformation compared to sever plastic deformation process.From Sever plastic deformation process ,we can also achieve a ultra fine grain structure,but it require a large plastic deformation.
Disadvantages of Cryo-rolling:
1.By doing Only cryo-rolling,we can not get a proper ductility.Subsequent annealing process is require,but it is a preferable
- For cryo-rolling process mostly we will use a Al & Cu material as it is a very soft and ductile material and it is not achieve easily a brittle structure at cryogenics temperature.
Resources/items needed for Cryo-rolling:
Thanks for your useful text. I have one question. What is the mechanism of ultra-fine grain structure (UFG) in Cryogenic Rolling? I will Be happy to know your opinion.