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IMPROVING SURFACE FINISH & INTEGRITY IN CLOSED DIES USING ULTRASONICALLY AGITATED ABRASIVES MIXTURES

Objective

The proposal is directed to the optimisation and demonstration of a method for automatic-control finishing of ide cavities in order to replace expensive manual finishing techniques currently employed throughout Europe.
The main project objective was achieved by the development of an ultrasonic flow polishing process for polishing blind cavities. The thermal and acoustic properties of the system have been quantified. A prototype polishing machine has been designed, constructed and demonstrated.

The process is capable of polishing to the quality specified in the project objectives (typically 10:1 improvement in Ra).

The technology has been patented and is currently undergoing industrial evaluation with a number of interested parties.

From a technical viewpoint the project has been very successful with all partners performing well as a co-ordinated unit. In addition to the technical achievements a number of non-technical achievements were experienced during the project term:

- a considerable amount of 'networking' has occurred. Partners and individuals have made contacts with third parties leading to further exchanges of information, meetings, new project ideas, etc.
- cultural exchanges have been significant through the technical and steering committee meetings which have occurred at the various partners' organisations
- the academic/industrial interface has been beneficial to all partners. As each meeting was hosted the activities and capabilities of each institute or company were demonstrated to the other partners
- the development of personal skills and acceptance of personal challenges was noticeable, particularly with personnel being exposed to working and communicating on an international level for the first time.
As finishing typically represents from 5 to 30 percent of production costs, such an automatic process would result in significant cost savings. This factor coupled with the improved surface quality would increase the competitiveness of many European companies, many of which would be SMEs. The suggested approach involves the ultrasonic agitation of polyborosiloxane polymer impregnated with abrasive grit. This compounds is fluid at room temperature and will thus conform to the shape of cavities of any dimension, whether of simple design or of a more complex nature. Applications would include finishing of precision forging dies and moulds, removal of recast layers and the introduction of residual compressive stresses on aircraft engine components. The programme would initially involve the determination of a suitable energization method for the polyborosiloxane/abrasive mixture. In addition the effects of curved transducers and the introduction of shear waves on the energy distribution, attenuation and heat generation would also be defined. Sample pieces would then be polished on test equipment to evaluate process variables. The final stage of the research programme would involve the design, construction and evaluation of a prototype ultrasonic polishing machine.

Coordinator

Extrude Hone Ltd
Address
Centurion Court 6 Brick Close
MK11 3JB Stony Stratford
United Kingdom

Participants (4)

BM Snc di Belluzzo & Co
Italy
Address
Via Torino 18/B
10044 Pianezza Torino
Ommp di Molgora Pierluigi
Italy
Address
Via Roma 32-34
22058 Osnago Como
Sheffield Hallam University
United Kingdom
Address
Pond Street
S11 9HG Sheffield
Société d'Etudes et de Recherches de l'École Nationale Supérieure d'Arts et Métiers (SERAM)
France
Address
151 Boulevard De L'hopital
75013 Paris