CemeCon's Diamond Coating Gives an Edge to HPTec's New Micro-milling Cutters

Würselen, Germany – Drilling and milling tools provider, HPTec GmbH, develops new micro-milling cutters ‘HPTec Composite Tool Action’ with CCDia AeroSpeed from CemeCon AG, a tool coating solution expert. The new micro cutters with diameters 1-3mm are precisely adapted for the machining of carbon fiber-reinforced polymer (CFRP) or glass fiber reinforced polymer (GFRP) composites, hard and highly abrasive fibers as well as a thermally sensitive matrix. The objective for HPTec was clearly defined when developing tools for trimming or contour milling of thin-walled FRP workpieces: A smooth surface was to be achieved without fiber residues, delamination, or component damage, and with maximum cutting force reduction.

The unique toothing or chip breaker profile and six cutting edges, the tools minimize the cutting forces by up to 80 percent. The small helix angles reduce the tensile and compressive forces as well as critical vibrations. An ultra-fine-grain carbide with a very high flexural strength was selected to provide high process reliability for the cutting material.

CemeCon has precisely matched the multi-layer coating material for composite processing and adapted it to the new tools in close cooperation with HPTec. CCDia AeroSpeed ensures very good chip flow and quickly conducts the frictional heat out of the contact zone.

Thanks to its extremely smooth and ultra-fine crystalline surface topography as well as excellent adhesion. This significantly reduces thermal stress and avoids delamination. With a hardness of around 10,000 HV0.05, the coating is highly resistant to the high-strength and highly abrasive fibers, thus ensuring long tool life. The diamond coating has crack-stopping properties leading to significantly higher process reliability, due to the patented multilayer structure. The new micro-milling cutters for machining fiber-reinforced plastics can achieve the best results only when each component (including machine spindle and tool holder) is matched to the complete system of the micromachining. So, that it can achieve the highest possible dimensional accuracy, surface quality and very long tool life.

"Particularly with small tools, it is important that the coating does not affect the filigree geometry and that the cutting edges are unintentionally rounded. For optimum wear protection, we have chosen a coating thickness of 9 µm for HPTec milling cutters. Nevertheless, the milling cutters coated with CCDia AeroSpeed have sharp cutting edges and thus separate the abrasive fibers much better than with conventional diamond coatings. There are no fiber protrusions, and the excellent quality of the milled surfaces can be reproduced at any time," adds Manfred Weigand, Product Manager Round Tools, CemeCon.

Image Source: CemeCon AG

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