Comparison of different theoretical models for flash temperature calculation under fretting conditions

The wear and friction properties of tribological interfaces depend signific antly on the contact temperature, and its determination is therefore import ant for each tribological application. Temperature calculation methods avai lable in the literature use quite different physical, dynamic and geometric al assumptions. Furthermore, the assumptions necessary for temperature calc ulations also include various interfacial properties, which are usually unk nown due to many difficulties in their exact determination. It is therefore important to know the possible differences between several frequently used models for flash temperature calculation and also the effect of these pre- assumed input parameters. In the present work the effects of the tribologic al interface between silicon nitride and steel under dry and boundary lubri cated fretting conditions were studied. Effects of the change of thermal pr operties. as well as the coefficient of friction and the real contact area on the calculated flash temperature are presented. Ten different theoretica l models were selected for the purposes of this investigation. The results show crucial differences between the various models and the significant imp ortance of the tribological interface properties on the calculated temperat ures. Based on these calculations, supported by experimental evidence, it i s clear that their severe limitations must be considered and care in the in terpretation of the results taken when such models are used. (C) 2001 Elsev ier Science Ltd. All rights reserved.