CoroDrill 880 CVD diamond-coated insert grades are specifically designed for demanding drilling.
CoroDrill 880 CVD diamond-coated insert grades are specifically designed for demanding drilling.

Sandvik Coromant has introduced new CoroDrill 880 CVD diamond-coated insert grades, GCN124 and GCN134.

The company says that the new grades can help overcome the challenges of chip formation and evacuation when drilling non-ferrous metals. The super-hard properties of the diamond coating provide a longer tool life and have with chip breaker and geometry designs to improve performance when drilling materials such as aluminum. The material is therefore suitable for automotive manufacturers drilling and boring aluminum components such as cylinder blocks, cylinder heads, knuckles, housings, brake calipers, control arms, transmission cases, steering-column covers and yokes.

The diamond-coated inserts can also be used by companies producing ISO-N parts, as well as those performing niche composite applications such as drilling glass fiber reinforced plastic rotors/blades for the wind turbine industry.

‘Making holes in aluminum can be a challenging task,’ said Patrik Pichler, Global product manager, indexable drilling tools at Sandvik Coromant. ‘Ductility and softness cause the material to make constant and prolonged contact with the insert’s cutting edges. As a consequence, the aluminum adheres to the cutting edge and creates a built-up edge (BUE) that makes chip formation and evacuation difficult.’

GCN124 and GCN134 diamond-coated insert grades are designed to offer the lowest cost per hole in most ISO-N materials due to long lasting insert tool life and/or greater productivity. The increased productivity could be gained from elevated cutting data as well as a result of less machine downtime thanks to fewer insert changes, Sandvik says. They also offer improved surface finish inside the hole, which results from the ability to resist BUE and smearing effects.

Production time

To highlight the potential of the new grades, when drilling a 22 mm diameter blind hole to a depth of 84.1 mm in a cylinder head made from 6061-T6 aluminum (90-100 HB), CoroDrill 880 mounted with the new N124 (peripheral) and N134 (central) inserts extended tool life from 700 to 3024 pieces; an 332% increase. The new insert permitted increased cutting speed, allowing productivity to increase by 33%. In total, some 300 hours of production time were saved, while overall cost per hole was reduced by 23%.

Similar success was achieved when performing through-hole drilling (22.5 mm diameter) in 20 mm thick automotive front control arms made from AISi1Mg-T6 aluminum (150 HB). Here, the CoroDrill inserts helped elevated tool life from 3,000 to 30,000 pieces. Productivity also improved by 10% as a result of less machine downtime for insert indexing, while cost per hole was reduced by 17%.

This story is reprinted from material from Sandvik Coromant, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier.