Synthesis, Mechanical and Tribological Characteristics of Immiscible Alloys

A modified impeller mixing coupled with chill casting technique was used for the preparation of immiscible alloys. In this paper Al-Fe binary alloys was chosen for this study. This binary system shows the miscibility gap at specified concentration and temperature. The electrolytic grade iron powder of 300mesh size was dispersed in the melt of commercially pure aluminum. The iron content in the composite varied from 1.67 to 11.2 wt%. Experimental quantitative expressions, which correlate UTS, yield tensile strength, elongation, wear volume and frictional coefficients to the presence of iron in the matrix, have been determined. The presence of iron in the composite improved the ultimate tensile strength, 0.2% proof stress and the hardness. The ductility showed the adverse effect with increase of the iron content in the matrix. The results from microstructure showed the presence of second phase particles at the grain boundaries of aluminum-rich phase as well as within the grain itself which was confirmed by EPMA line as well as XRD analysis. The experimental data refer to correlation with the directional transient solidification of hypereutectic Al-Fe alloys and the percentage of the iron in the matrix. These composite have also been subjected to wear and friction testing at different operating parameters. The XRD analysis was used to analyze the wear debris.