Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

The development of an ion implantation process for improvement of rolling bearings in gas turbine engines

Research developments include:
manufacture of the test coupons and polymet rods in the main aero bearing steels, M50 and Tl, and also the new carburising steel M50 NiL;
design, manufacture and commissioning of component handling and beam scanning systems, including a dedicated ball manipulator for the uniform implantation of balls;
successful implantation of all test coupons and polymet rods with the metallic species chromium and tantalum and dual implantation of yttrium plus nitrogen, each at 4 different dosage levels;
corrosion testing of implanted test coupons using potentiometric polarisation, open circuit potential versus time, and cyclic voltametry. The results of the corrosion tests show a significant improvement in the corrosion resistance of M50, Tl and M50 NiL materials implanted with chromium and tantalum;
characterisation of the implantation regimes using Rutherford backscattering (RBS) and nuclear reaction analysis (NRA) techniques.

The main achievements include:
development of an ion implantation technique for the implantation of bearing components with chromium, tantalum and yttrium plus nitrogen;
testing of implanted components to assess and quantify benefits gained;
proving the capability of maintaining these benefits under severe service conditions;
identification of possible nondestructive techniques which can be used as quality assurance tools for ion implanted bearing components.

Consequently, the service life and reliability of gas turbine bearings has been improved by increasing their corrosion resistance and their rolling contact fatigue life.


Andrew DODD
Tel.: +44-602-405409
Fax: +44-602-405419