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Abstract
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The Al6061-ZrO2 composites were produced using a low-cost stir casting technique, for the first time. The microstructures, mechanical properties, and electrochemical behavior of the composites contacting different amounts of ZrO2 ceramic reinforcements were studied in detail. The results revealed that the weight percentage of ZrO2 ceramic reinforcement was the most effective parameter affecting the properties of composites. The optimum mechanical properties and corrosion resistance were achieved when adding 3 wt.% ZrO2 at 700°C due to the uniform distribution of ceramic reinforcements, elimination of agglomeration, finer grain sizes, and no chemical reactions between the ZrO2 ceramic particles and Al matrix. The maximum elastic modulus of larger than 80 GPa, the maximum hardness of 1.39 GPa, and the highest wear resistance were obtained at optimum condition. From the viewpoint of electrochemical behavior, the optimal composite showed higher pitting resistance with the lowest thermodynamic tendency to corrosion because ZrO2 ceramic particles are less prone to corrosion. In addition, at a higher amount of ZrO2, the formation of a continuous protective layer on the surface is postponed, which leads to lower corrosion resistance.
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