The principal benefit of ceramic over carbide inserts is greater heat resistance, which allows cutting speeds up to 20 times higher than could be achieved previously. According to Ceratizit, surface speeds of up to 1000 m/min are possible. Although carbide inserts remain as the cutting material of choice when finish machining HRSAs, the development of ceramic insert technology is highly cost-effective for rough machining due to the significant cycle-time reductions brought about by the elevated cutting data.
Team Cutting Tools’ latest ceramic grades for this purpose are the SiAlON-based CTIS710 and the CTKS710. The latter is a whisker reinforced ceramic, which benefits from greater toughness than SiAlON (silicon nitride) based inserts.
These newly developed grades deliver high surface speeds and extended tool life. By way of example, using a CTIS710 insert to machine a turbine blade from Nimonic 80A at 1,000 m/min cutting speed, feed per tooth of 0.1 mm and 3 mm depth of cut, meant that tool life was 50% greater than the customer had experienced with its existing ceramic inserts.
To complement the inserts, Ceratizit has developed the MaxiMill 261 series of milling cutter bodies, which are available with either a positive or negative approach angle. Swarf removal and cooling is enhanced by the design of the tempered steel clamping claw, which directs compressed air directly to the cutting edge.
“With the demands of the aerospace sector and its use of HRSA growing, the challenge to provide ever more efficient and cost effective metal-cutting solutions is vitally important,” says Tony Pennington, managing director at Ceratizit UK & Ireland. “Therefore, the development work that the Ceratizit Group is undertaking, and the delivery of that technology by engineers within Team Cutting Tools, is playing an important role in keeping cycle times to a minimum and delivering productivity gains to our customers.”
