Chip evacuation on a machining center has been key to part quality, finish and integrity. For years, plastic line and metal tubing were the only way to flush the chips away as they were being cut. Then cold air, high-pressure coolant delivery and other methods followed.

Coherent jet coolant delivery has been around for over a decade. It has been used predominantly in grinding. But what would happen if it was applied to machining? Would the results be similar to the changes seen in grinding? Would the machined chips be flushed away faster with better lubrication to the cutting tool?

Recently a test was done using coherent jet coolant delivery on a vertical machining center. The machine uses a 300-psi pump. The material being machined is Inconel. On the original setup four plastic lines were being used and directed to the cut.

The test was looking to achieve several changes in the machining the part: increase tool life, better material integrity after machining and improve part finish. All three were accomplished.

First, the four plastic lines were removed from the coolant manifold and replaced with two coherent jet SwivelJet coolant lines from Productivity Solutions Inc. designed for the test. The new Swiveljet lines being used could be reconfigured easily and were capable of handling the coolant pressure.

The feeds, speeds and depth of cut were kept the same as when the plastic lines were used. Measurements were being taken while the test was being run. Power draw was reduced by over 35 percent. Chatter was lowered to less than a half. And the tool life was doubled.

Given the high nickel content of the part, it can be generalized that other high nickel alloys such as titanium would also benefit greatly from coherent jet coolant delivery. Tests will soon be run on stainless steels that can be difficult to machine such as 17-4 and 400 series medical grades of stainless steel.