BRITE/EURAM-PREDWEAR (BE-5248)

Title: Development of a Decision Support System for Predicting Wear in Bulk and Sheet Forming Processes

Partners: Rockfield (GB), British Steel (GB), Instituttet fur Produktudvikling (DK), Universidad Politecnica de Cataluna (ES) Techint Compagnia Technica Internazionale (IT), Matrix (E), Universita di Padova (IT), Candemat (ES)

Summary: The main objective of this research project is to enhance available decision support systems used in the industrial design and optimisation practice to take into account the phenomena of wear. To meet this objective a consortium of experts specialised in micromechanical and experimental research of wear, numerical analysis and tool and steel product manufacturing has been set up to undertake research in the following areas:

Micromechanics of wear: The phenomena of wear are extremely complex and an attempt to understand and quantify the mechanisms involved requires fundamental studies at the micromechanical level. The aim of such studies is to develop appropriate micromechanical models and to analyse them in order to estimate wear in terms of sliding distance, sliding velocity, contact pressure and temperature for given tribological contact conditions such as surface hardness and roughness, lubricant film thickness, etc.

Experimental evaluation of wear parameters: The parameters of micromechanical wear models are evaluated from laboratory tests which must be carefully designed to simulate contact conditions encountered in industrial forming operations. Since there are no tests available in which uniform interface conditions can be maintained throughout the experimental test, the actual distribution of testing conditions need to be monitored by means of indirect measurements and inverse analysis techniques.

Finite element modelling: One of the main aims of this project is to implement the constitutive relations of wear derived from micromechanical models and laboratory tests into a finite element based decision support system which permits estimation of wear by predicting sliding distance, sliding velocity, contact pressure, temperature and other state variables. The numerical simulation is supported by physical modelling for complex shapes in hot forging.

Industrial application: The phenomena related to wear have an important impact on the economy of metal forming operations. The statistics show that wear is, to within approximately 60-70%, the dominating failure mechanism for hot forging dies and has therefore an important influence on the production costs of forged products. However, methodologies currently used in an average European forging shop to optimise the service life of forging dies are primarily based on designers' intuition and experience, which is not adequate when considering the complexity of the problem. Experts claim that a more quantitative approach to die design can improve service life considerably, which suggests that this area of optimisation provides a good opportunity for economising forging production.