Superalloys sawn twice as quickly, and scrap eliminated

Citation

(2008), "Superalloys sawn twice as quickly, and scrap eliminated", Aircraft Engineering and Aerospace Technology, Vol. 80 No. 1. https://doi.org/10.1108/aeat.2008.12780aab.003

Superalloys sawn twice as quickly, and scrap eliminated

Superalloys sawn twice as quickly, and scrap eliminated

Cycle times for cutting nickel and titanium alloy materials are reported to have been halved at the Milton Keynes stockholding centre of Aviation Metals following the installation of a KASTOtec AC4 bandsaw (Figure 1). Designed for running tungsten carbide tipped blades, the machine was fitted at the German factory with a more powerful motor and special gearbox to deliver higher torque at low speeds for cutting tough superalloys more efficiently (Figure 2).

Figure 1 The KASTOtec AC4 bandsaw at Aviation Metals, Milton Keynes

Sawing of fully heat-treated engineering steels is even faster, with typically a 60 per cent reduction in cutting cycles reported. The comparisons are with the bandsaw previously used, on which the carbide blade was run by a motor approximately half as powerful as the 11kW drive on the KASTO machine.

Figure 2 This 95mm diameter bar of Inconel 718 is sawn to length on KASTOtec AC4 in 7min, whereas it used to take 14min to process on a lower power carbide bandsaw

Aviation Metals, a division of Apollo within the privately owned, £500m- turnover Murray Group, is a leading distributor of cut, profiled and machined steels, superalloys and aluminium products to the aerospace, defence and other high-technology industries. In 2006 it won the coveted accolade from Airbus of “best service supplier” following an international survey of the aircraft OEM's factories.

Lee Turner, Customer Service Manager – operations at the Milton Keynes site, said that the KASTO machine is so productive it will pay for itself within 16 months, based on increased output over 48 weeks of two-shift working, five days a week. The amortisation period is conservative, as it was based on day shift labour rates and did not take into account higher rates at night. The 4h period of unattended running between the 8h manned shifts each day was not factored in either, even though it is a net gain, as it is not possible on the other bandsaws.

Commented Mr Turner, “We went over to KASTO's factory in Achern to see the AC4 demonstrated, then calculated the payback using the machine specification in the brochure. What we predicted is happening in practice. It means that the machine, which was installed at the end of February this year, will easily have paid for itself by July 2008”.

Robustness of construction is a merit of the construction of KASTOtec bandsaws, as is their use of a 50mm wide blade that is more rigid at high speeds than the 41mm blades used on other saws at Milton Keynes. Another first on the shop floor is constant blade deflection monitoring on the AC4, with automatic machine shutdown if a preset tolerance is exceeded. Staffs are therefore confident when leaving valuable stock up to 430£430mm cross section to be cut unattended.

Continued Mr Turner, “Between three and four per cent scrap rate is usual when cutting these difficult materials yet we have had no scrap at all from the KASTO machine, leading to a large additional saving.” “The control is easy to program with stock dimensions, required number of cut pieces, band speed and infeed rate, after which the cycle is automatic, so the resulting cut pieces are more consistent than on our manually set saws.”

“Additionally, as the front vice is behind the blade, the rest piece at 35mm is around one third that of other bandsaws, leading to even more material savings.”

Service back-up from KASTO's Southampton subsidiary is regarded as very good. In addition to the usual areas like training, Mr Turner was impressed with the speed and lack of fuss involved in retrofitting a twin-button control to operate the saw. The option had been overlooked at the time of order, although it is Aviation Metals' policy to have dead-man controls fitted to its machinery.

Concluded Mr Turner, “Nearly all our stock at Milton Keynes is cut to length for customers to a tolerance of -0/+1mm. Only about 20 per cent of output is aluminium, however, so a majority of the throughput involves sawing hard and/or tough metals.”

“Despite this, the uptime of the KASTO saw has been amazing and there have been no major issues. It is without doubt the best saw on the market for repetition cutting of nickel- based superalloys.”

Details available from: KASTO Ltd, Tel: +44 (0) 1489 772882, Fax: +44 (0) 1489 772888, E-mail: sales@kasto.uk.com, web site: www.kasto.uk.com