Effect of alumina nanoparticles on hot strength and deformation behaviour of AI-5vol% Al2O3 nanocomposite: experimental study and modelling.

Hot deformation behaviour of as-extruded Al-5vol% Al2O3 nanocomposite was investigated at temperatures range 350 to 450 degrees C and initial strain rates of 5.5 x 10(-4) to 10(-1) s(-1) and compared with those of monolithic (unreinforced) aluminium. Both extruded materials exhibited work-softening during hot deformation. The results showed that with the addition of 5 vol% alumina nanoparticles with an average particle size of 35 nm, a significant increase in compressive strength of aluminium was obtained. For instance, at 350 degrees C an abrupt rise of approximately 340% in hot strength of the nanocomposite relative to monolithic aluminium was achieved. TEM investigation of microstructure of the nanocomposite after hot deformation showed formation of equiaxed grains from elongated ones indicating the occurrence of dynamic recrystallization. Considering experimental data, deformation behaviour of Al-5vol% Al2O3 nanocomposite and monolithic Al was modelled via trained artificial neural network (ANN). The results showed that ANN can predict complex flow behaviour of the nanocomposite as well as the monolithic aluminium.