News | July 17, 2018

Turn-Round In Productivity And Process Security

New ceramic grades aid high-speed turning in demanding HRSA materials

Cutting tool and tooling system specialist Sandvik Coromant is introducing two new ceramic insert grades that are capable of performing high-speed, high-security turning operations on components made from demanding HRSA (heat resistant super alloy) materials. The CC6220 and CC6230 ceramic grades have been developed to machine demanding materials where whisker ceramics and SiAlONs fall short. Their ability to handle higher cutting speeds contributes to reduced cost per component, while inherent machining security ensures that quality is not compromised to help manufacturers produce high quality parts, time after time.

There is growing demand for aerospace engine parts that can withstand extreme temperatures beyond the capability of those made from Inconel and other high-performance super alloys. Although these powder metallurgic materials can be tailored to handle substantially higher temperatures, they are more difficult to machine than common HRSAs.

“CC6220 and CC6230 excel when turning demanding materials in intermediate stage machining,” says Rolf Olofsson, Product management turning at Sandvik Coromant. “They take productivity to a new level in comparison with whisker ceramics and SiAlONs, in terms of both cutting speeds and feeds. Moreover, repeatable quality is assured.”

Along with productivity improvements of more than 50% over whisker ceramics and SiAlONs, CC6220 and CC6230 offer long tool life in challenging HRSAs, and thereby lower cost per part.

One of the most common applications to benefit is expected to be the turning of turbine discs. In a customer example machining a low-pressure turbine (LPT) disc made from Rene material (42-45 HRc) as part of the intermediate stage machining process, a CC6220 RPGX insert was deployed to perform pocketing and CC6230 RPGX inserts for rough-turning operation at cutting speeds as high as 400 m/min (1380 sfm). The process achieved a metal removal rate (MRR) of 80 cm3/min (5 inch3/min).

Similar success was achieved for a subsequent semi-finishing operation at lower cutting speed and long time in cut. Importantly, all of the specified quality requirements were attained on a repeatable basis thanks to the process security provided by the new grade.

Aside from the aerospace industry, other sectors expected to benefit from CC6220 and CC6230 include power generation (turbine components in Inconel and Hastelloy), and oil and gas (parts cladded with Stellite 6, for example).

SOURCE: Sandvik Coromant