A research project at Cranfield University has employed Holroyd’s superabrasive Edgetek machines to achieve significant breakthroughs when machining nickel-based superalloys.
The breakthroughs, in terms of reduced cycle times, better surface finish and improved accuracy, have been achieved using the latest high efficiency deep grinding (HEDG) techniques. They are likely to have a profound influence on the way that superalloys are machined in the future within the aerospace industry. The Cranfield team, led by Professor David Stephenson, carried out lengthy “burn threshold studies” on Inconel 718 – a superalloy commonly employed for gas turbine components, using Holroyd’s Edgetek superabrasive machining process. Manufactured at Holroyd’s UK factory in Rochdale, the multi-axis, CNC controlled Edgetek machines deploy deep grinding (HEDG) techniques, using cubic boron nitride (CBN) wheels at surface speeds up to 200m/s. This enables them to achieve high depths of cut and optimised metal removal rates far exceeding those of more conventional machines, such as CNC lathes, milling and machining centres and grinders. An Edgetek machine (a five-axis unit) was specified for the Cranfield research project due to its ability to machine nickel-based superalloys such as Iconel 718, which are extremely difficult to work.
The ability of these alloys to retain much of their strength at elevated temperatures means that wear rate on conventional tooling is rapid, even when cutting at low speeds.
