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(2020) 20:98

ORIGINAL ARTICLE

Microstructure and mechanical properties of CuZn‑Al2O3 nanocomposites produced by friction stir processing Akbar Heidarzadeh1   · Babak Taghizadeh2 · Ahad Mohammadzadeh2 Received: 9 June 2020 / Revised: 8 July 2020 / Accepted: 31 July 2020 © Wroclaw University of Science and Technology 2020

Abstract For the first time, ceramic nano particles were incorporated into the brass alloy to produce surface nano composites by friction stir processing. For this aim, A ­ l2O3 particles with an average diameter of 30 nm were inserted into a Cu-37Zn alloy at different tool rotational speeds of 450, 710, and 1120 rpm, multi passes, and a constant traverse speed of 100 mm/min. The microstructures of the processed materials were analyzed using optical and scanning electron microscopes equipped with an energy dispersive spectroscopy. In addition, tensile test was employed to evaluate the mechanical properties. The results showed that the optimum rotational speed was 710 rpm. At lower rotational speeds, ­Al2O3 particles were agglomerated. On the other hand, at higher rotational speeds, tool was damaged by severe wear. The effect of multi passes showed that one and two passes could not distribute the A ­ l2O3 particles, uniformly. However, three passes resulted in a uniform distribution of the ­Al2O3 particles inside a bimodal grain structure composed of both 3–5 μm grains and ultra-fine grains (