Correlations between stereological parameters of carbon component and tribological properties of heterophase composites Al-Al2O3+C
Bartosz Hekner, Jerzy Myalski
Quarterly No. 2, 2016 pages 67-73
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abstract This paper is an attempt to describe the influence of the stereological properties of the reinforcement on the final material properties. The research was carried out on Al based composites with a heterogeneous reinforcement of Al2O3 and C. Various sizes of the carbon particle component (< 40, 80÷120, 160÷200 and < 200 µm) were applied for material manufacturing. The materials were obtained by high energy ball milling and subsequent hot pressing processes. As a result of the milling stage, a reduction in the compound size was observed. First, the real size of the carbon component, the real amount of carbon on the material surface and other properties were measured by quanti-tative metallography methods. Then, the correlations between the obtained stereological parameters and the tribological properties were checked. The analysis revealed that the average size of a single carbon particle and the distance between adjacent particles are the most important factors for the tribological properties of Al-Al2O3+C composite design. The larger the size of particles and the greater the distance between the particles resulted in increasing the friction coefficient value. It is related to the homogeneous distribution of the reinforcing component. However, the most surprising effect was discovered during analysis of the areal fraction of C particles. There were no clear correlations between the amount of C particles and the tribological properties. The conducted research revealed which of the analysed parameters are the most valuable for material design and predicting the final properties. Keywords: stereological parameters, tribological properties, aluminum matrix composite, carbon component, high energy milling