Time for change in Composites Chip Removal Machining
PTFE (PolyTetraFluorEthylene – Teflon ™), PMC (Polyester Matrix Composites), CFRP (Carbon Fiber Reinforced Plastics) offer high performance requirement in boating-yachting, aeronautical or aerospace industry. However, they may evidence also problems like delamination and poor surface quality during machining, especially why the tooling life seems to be very short due to the abrasive properties of the processed materials.
All these issues can be avoided, and time and costs can be in the same time reduced, simply using a special PCD tools with laser sharpening.
PCD (PolyCrystalline Diamond) was the lead actor, the star, in special tests recently carried out in an advanced workshop of a F.1 Leading Team (whose name is under No Disclosure Agreement). Chip machining special PCD tools gave excellent results. Isn’t it not possible to report the precise technical data for the reasons above mentioned, however it was clear in the final report that laser sharpened, polycrystalline diamond cutting tools edges for the appointed machining achieved benefits of 30% in terms of cost reduction.
In fact, the laser technology allows the optimal sharpening of the diamond cutting edge and also its profiling in special shapes, developed on customers’ requirements. This is the premise to avoid the development of heat due to the friction between cutting edge and machined material. As known, precisely heat development is the main cause of deformation, as well as an incorrect machining may effect shrinkage, fibrous outcrop, chipping of edges, and delamination.
All these difficulties can be avoided refining case by case (on different composites) the machining parameters of the diamond tool:
– using very high tip angles (150-180°)
– selecting very low forward speed (<0,05 mm/min)
– using high cutting speeds (300-400 m/min)
The use of PCD is not a brand-new entry, but laser technology on PCD cutting edges show new scenarios: bespoke solutions can be developed for every different kind of needs of composites’ machining. Simplifying machining process, it is possible to achieve a better surface quality. Moreover, cutting edges can be sharpened more and more times.
It is time to change.
(see also COMPOSITI – Page Nr. 19)