High Speed Machining

Machining MMC is challenging due to the hard silicon carbide particles causing a high abrasive wear on the cutting tool, resulting in very expensive machining. However, with the method developed and patented by Saab, the tool wear is minimized by utilizing the phenomenon provided by High Speed Machining.

High Speed Machining (HSM) is a machining technology where the cutting tool is rotating at very high speeds resulting in a high cutting speed (the periphery velocity of the cutting tool).

The high speed results in an elevated level of energy concentrated on a very small area thus soften the material locally and produce a small crack in front of the cutting edge, which means that the edge does not get in contact with the particles as in conventional machining. The phenomenon can be illustrated by studying the cutting forces acting on the tool.To the right the cutting force is plotted as function of the cutting speed and it could be seen that the cutting force is decreasing after a certain cutting speed, the speed that creates enough enery to start the adiabatic softening.

The patented method utilize cutting parameters and cutting tools that accomplish the above described phenomenon which can be defined as machining when cutting force, as a function of the cutting speed, is decreasing (the shaded part of the curve).