Analyze different phases in Al-Cr-O hybrid nano-composites developed by friction stir processing

In this study ratio of slopes method (RSM) was used for quantitative analysis of different phases in Al-Cr-O hybrid nano-composites that are developed on the surface of Al6061 plate by using friction stir processing(FSP). Combination of the hot working nature of FSP and the exothermic reaction between aluminum and Cr2O3 developed Al-Cr-O nano-composites. For applying the reinforcement particles a new procedure was used, in which Cr2O3 powder was applied on Al6061 plate by atmosphere plasma spray (APS), and then the FSP was performed on the plate. After six FSP passes, the microstructure of nano-composite included Al, Cr, Al2O3, Cr2O3, Al13Cr2 and Al11Cr2 phases. During first three passes of FSP, due to thermomechanical situation, Cr2O3was reduced by aluminum and so Cr and Al2O3 were produced. With increasing the number of FSP passes, intermetallic compounds including Al13Cr2 and Al11Cr2 were developed. For quantitative XRD analysis, CaF2 was used as standard material. For Al and Cr2O3, known purity materials were available but for other phases RSM without reference material was employed. Results of quantitative analysis indicated the range of 76.82-66.48%Al, 6.04-6.86%Cr, 7.12-11.4% Al2O3, 10.02-5.03% Cr2O3, 5.00-8.54% Al13Cr2 and 5.02 Al11Cr2 in five different nano-composites.

Keywords:

Quantitative analysis , Ratio of slopes method , Hybrid nano-composites , Friction stir processing , Al-Cr intermetallics