Wear Particles Identification and Modelling Degradation Processes of the Combustion Engines Possibilities

In general, machine military technique part wear does not depend only on the friction characteristics (rolling or sliding friction), but it is a complex physicalchemical process that occurs on sliding surfaces of the tribological units. An external, undesirable product of the friction system activity is a very wide spectrum of wear particles. With respect to diagnostics it is important that these particles contain multidimensional, complete information on the wear mode, and generally on actual technical condition of the military systems. A complex military mechanical engineering product (e.g. combustion engine) consists of many friction pairs, and their surfaces, by being in contact, simultaneously produce wear particles. The task, based on the study of number, morphology, shape, size, colour of particles, is to identify which tribologically significant processes run in the system. The decisive factor is a production of characteristic particles that corresponds to the characteristic modes of wear. Wear dynamics can unambiguously be defined and assessed by intensity of creation, material comparison, distribution, size, morphology of particles, etc. The paper deals with ways of applying mathematical methods to evaluate the result of tribodiagnostics related to military vehicle combustion engines. The idea is based on a discriminative analysis that makes possible to describe one qualitative parameter (complex technical state) by means of several quantitative parameters (i.e. quantity of diagnostic parameters). The result have been verified by means of considerable statistical data of T-3-930 engines made in the Czech Republic which are used in ground military vehicles. 1.0 INTRODUCTION – EVALUATION OF MACHINE SETS WEAR MODE Generally, wear depends not only on the friction character (rolling or sliding) but also on a complex physical-chemical process occurring on the sliding surfaces of a tribological unit. An external undesirable product of the friction system action is a very wide range of wear particles. From the diagnostic point of view, it is important that these particles carry nearly comprehensive information about the mutual connection among individual elements of such a system, that is, what the conditions for production of the particles in individual friction couples are. A combustion engine is characterized by simultaneous contacts of many friction couples and, thus, also by simultaneous production of wear particles at all of these points. The problem is, on the basis of number, shape, size, or coloration of the particles, to determine what tribological processes are in progress in the engine. Wearing dynamics can be evaluated according to: intensity of particles production, material composition of particles, distribution of particles ́ size groups, morphology and shape of particles ́ surface features, etc. Paper presented at the RTO AVT Specialists’ Meeting on “The Control and Reduction of Wear in Military Platforms”, held in Williamsburg, USA, 7-9 June 2003, and published in RTO-MP-AVT-109.