With the development of high-resistance and refractory materials in the medical, energy and aeronautics sectors, a review of machining processes is urgently needed. One process stands out: cryogenic-assisted machining, which offers the undeniable advantage of improving tool lifetime thanks to the possibility of highly efficient cooling of the cutting edge.
Although two implementation technologies coexist and are currently used in various ways, in the absence of any published reference documents on the subject it is difficult to compare them.
This comparative study on cryogenic-assisted milling aims to provide a technical comparison of three technologies – Dry To Fly liquid nitrogen, Cool Clean Technologies and Fusion Coolant Systems – applied to an application case involving rough milling of a titanium alloy, precisely detailing the conditions of the experiment, the material machined and the machine tools used, as well as the instrumentation, without forgetting the assembly stage.
It is the tool lifetime tests, however, that remain the central focus of this study.
Three cryogenic assistance technologies were compared for a Ti-6Al-4V milling operation.
The results show that, regardless of the technology, cryogenic assistance significantly increases the lifetime in comparison to machining using emulsions.
The introduction of microlubricants into CO2-based solutions seems to have a positive effect on adhesive phenomena. The development of an LN2 solution with microlubrication could improve lifetimes.
For practical and financial reasons, it was not possible to compare these technologies using the same machining centre at Cetim. Based on the wear surface, the resulting bias is moderate, but should be taken into account when reading the results.
In this study, the only criterion quantified was lifetime. Other elements may come into play when comparing technologies :
- the repeatability of lifetimes.
- technical and economic issues.
- the environmental cost of the whole cycle (from the production of the cryogenic fluid to its disposal).
- the feasibility of integration into existing machines.
Access to the complete document (in English and French version) is given here :