Mill faster by eliminating Thermal Shock Mill faster by eliminating Thermal Shock
With conventional coolant, the cutting edge comes up to a very high temperature as it enters the cut, stays hot until it finishes the cut and is exposed to an extreme thermal shock as the coolant quenches the exposed tool. Most cutting tool companies recommend wet turning but they ask you to mill dry even when the carbide, coating, and work piece material are the same. With turning, there may be only 3 or 4 passes per minute and, therefore, only 3 or 4 thermal shocks. With milling, every time the cutter makes a full rotation each insert gets hot and is quenched. With conventional flood coolant, a face mill running at 1000 RPM subjects every insert to a 1000 damaging quenches every minute. This rapid cycling between high temperature and quench is more damaging than heat or wear. Tooling manufacturers recommend dry milling, because they believe that the continual heat and chip damage is better than thermal shock damage. Old fashioned milling cutters that are still commonly in use were designed for slow open manual machines. The pilot and key system has no provision for coolant and the connection was designed for high speed steel shell mills that might have cut at a few hundred RPM. This system was never intended to provide the strength and balance that are required by modern CNC machine tools. Coolant can’t get to the point of the cut, so temperatures are intermittently very high.
" It is well known that an inverse proportion exists between temperature and tool life. At certain temperature values, even a very small change in temperature can have a significant influence on wear behavior and tool failure" -SME MRR92-11
Milling cutters must
have an integral shank or modern face lock connection with coolant delivery
designed into the tool and connection system so that the coolant is always where
it is supposed to be. This coolant technology eliminates temperature increases
and keeps damaging chips away from the cutting edge. The damage that occurs with
old-fashioned systems is eliminated. ChipBLASTER offers a variety of modifications to your existing mill cutter allowing 1000PSI through your tool.
Milling and Turning Speeds & Feeds
