Quantitative comparison of the microstructural quality of two classes of commercial soft triboalloys

The desired properties and microstructures of journal bearing alloys have traditionally been described in qualitative terms. Due to the composite nature of the alloys, an objective assessment of their microstructural quality cannot be made in this way. To analyse the variation of microstructures in nominally equal commercial products and to provide a tool for future product optimisation, quantitative metallographic techniques were adopted instead. Data on grain size, contiguity of phases and homogeneity of the dispersion of second phase particles were obtained for an extended lot of industrially produced alloys. The quantitative analysis contradicts some of the intuitive conclusions based on visual inspection and allows to pinpoint areas for further process optimisation.