RHEOLOGICAL BEHAVIOUR AND MODEL OF ALUMINA-POLYMER-BASED COMPOSITE SLIDING BEARING

摘要

In the paper mechanical properties and tribological parameters of composite bearing comprising alumina-aluminum-polymer-steel substrate have been investigated. Better understanding of fundamentals of thermal flame spraying process used to produce both aluminium and polymer layers and micro arc oxidizing process used to transform aluminum into hard alumina have discovered semi-empirical relations to be used in the bearing design providing preferred by customer mechanical properties and performance. Study of technological aspects reveals semi-empirical relations to calculate thickness of aluminum and polymer layers of composite bearing providing rational strength and adhesion. An analysis of structure and porosity in depth of alumina revealed that the structure of the layer contains ?, ? phases of aluminum oxides, porosity ranges in 5-11%. Microhardness of the layer reaches 12-15GPa, that is very high result for alumina layer on sprayed aluminum in contrast to traditionally produced on cast aluminum alloys. An analysis of fatigue behavior of the bearing revealed an effect of structure and porosity of alumina on degradation and overall strength of the composition. Of interest is revealed very close correlation between developed rheological model and real mechanical behavior of the bearing under indentation. Actually, an experimental research of load rating is in good agreement with rheological model to be applied in analysis of the composite bearing mechanics.