End Mill Comparisons in CFRP, Part 2 - Diamond-Coated Tool

Smith MegaDiamond Inc. and Star Cutter Company compared the performance of various end mills in carbon fiber reinforced plastic (CFRP). The tools tested included a coated carbide end mill, a diamond-coated end mill, a conventional PCD end mill with straight flutes, and a “veined” PCD end mll featuring a vein of PCD within a helical slot in a carbide tool body.

The table below summarizes the test parameters. Shown here is the video of a 10-degree helical diamond-coated tool. Jeff Michael, engineering manager for Star Cutter, comments, “Again, the sound is pretty good with this cutter, but uncut fibers appear immediately. This is because a tool’s coating tends to give it a more rounded cutting edge, making it more difficulty to cut the fibers cleanly off.”

To see the next video in this testing, click here.

 

 

	Tool Type
Ø .500 in.	Solid Carbide	CVD Diamond	PCD	Veined PCD
Flute angle	30° helical	10° helical	7° skew	30° helical
Spindle speed (rpm)	3,000	4,600	12,000	18,000
Chip load (in./tooth)	0.0035	0.0035	0.001	0.0065
Machine advance (in./min.)	42	64	36	470
Radial depth (in.)	.050	.050	.050	.050

Cutting speeds and feed rates were recommended parameters from each tool’s manufacturer.

 

Editor’s note: To read the next part in the series, click here.