Productivity improvement in machining Inconel and other HRSA materials

Citation

(2007), "Productivity improvement in machining Inconel and other HRSA materials", Aircraft Engineering and Aerospace Technology, Vol. 79 No. 6. https://doi.org/10.1108/aeat.2007.12779fab.001

Productivity improvement in machining Inconel and other HRSA materials

Productivity improvement in machining Inconel and other HRSA materials

Challenged with improving productivity in rough machining operations of aero engine components, engineers at Sandvik Coromant report that they have applied the new CC6060 ceramic grade to great effect.

Face milling the notoriously difficult Inconel 718 material, used in the manufacture of highly stressed engine casings, the Coromant grade CC6060 is said to have reduced the cycle time on the single component feature by approximately 97 per cent. This equates to an annual cost saving of e 25,098.13 (£17,000 GBP) on the anticipated throughput of casing components. According to Sandvik Coromant this comparison was made against a competitor's coated carbide grade, using the customer's hourly machine cost rate.

Ceramic grades claim the capability to run at up to 40 times the speed of conventional carbide inserts and are used mainly for rough machining applications. The new Sialon grade CC6060 is optimised to deliver higher productivity when machining in dry conditions. With an excellent notch wear resistance, this grade is said to provide the confidence to machine at higher speeds and feeds than other ceramic grades currently available.

A demonstration of its capabilities was carried out for a leading aerospace component manufacturer, the tool holder was changed to the latest Coromant Capto integrated ceramic face milling cutter fitted with 12mm diameter CC6060 inserts. Consequently, it was possible to increase the cutting speed to 1,000m/min (previously 25m/min) while pushing the feed rate to 1,512mm/min (previously 55mm/min). This is achievable because of the CC6060 grades' extreme resistance to heat. The result produced was reported to be a dramatic reduction in cycle time of 97 per cent.

Much of the initial testing prior to the on-machine comparison at the customer's premises took place under independent analysis at the Advanced Manufacturing Research Centre (AMRC) in Sheffield, UK. (Sandvik Coromant is one of AMRC's partners in its commitment to develop new materials and techniques for advanced manufacturing, particularly in the aerospace sector.)

Sean Holt, application development specialist Sandvik UK, emphasises, “Grade CC6060 should be considered first choice for open profile machining in stable conditions. It put demands on tailored programming techniques to control engagement angle, entry and exit from the component, etc. However, when these techniques are applied it delivers improved productivity through increased metal removal rates”.

According to Sandvik Coromant these complementary Sialon based grades will successfully improve the machining of HRSA materials. (Sialon is a ceramic made from a mixture of Silicon Nitride and Aluminium Oxide containing Silicon, Aluminium, Oxygen, and Nitrogen; the combination offers the best chemical stability for resisting notch wear.)

A major part of AMRC's activities involves investigating new and emerging materials and establishing how they can be cost effectively used in manufacturing aircraft components of the future. It was against this background that the initial customer tests using HRSA materials and the Coromant CC6060 grade were undertaken.

Details available from: SANDVIKCOROMANT; Tel: +44 (0)121 504 5422; Fax: +44 (0)121 504 5565, E-mail: nikki.stokes@sandvik.com