چكيده به لاتين
Nowadays Metal-matrix nanocomposites are widely used in different industries. Among the mentioned composites, nanocomposites with Aluminum matrix consisting of reinforcements such as Silicon Carbide, Aluminum Oxide, Titanium Carbide, Boron Carbide and ... have become more popular due to many reasons and are produced by several methods. Among these ways, casting method is of greater importance and attention because of having a higher production rate and lower costs compared to other methods. However, these nanocomposites face too many problems in forming process as a result of casting defects. Therefore, concerns related to forming process of Aluminum-Matrix nanocomposites produced by casting is the reason that this study is performed. In this study, samples were cast with A356 alloy as the matrix and 50 nm alpha Al2O3 particles with weight percentages of 0.5, 1 and 1.5 as reinforcing components. A furnace equipped with an electro-magnetic stirrer was used. Afterward, the samples were tested with the hot press under strain rates of 0.001, 0.01, 0.1 and 0.5 per second and 350, 400, 450 and 500 Celsius degree temperatures. The samples were also tested under uni-axial pressure in room temperature with the strain rate of 0.0007. optical and scanning electron microscopes and X-ray diffraction spectroscopy was used in order to Find out different characteristics of the samples, after checking the concluded results, we came up to this point that the UTS of nanocomposites is reachable in 400 Celsius degree temperature and strain rate of 0.5 per second which is due to the activation of dynamic recrystallization mechanism under these circumstances. It was also concluded that by decreasing weight percentage of hardeners in the matrix from 1.5 to 0.5, yield and ultimate compression strength were increased by 10% and 15 %, respectively which represents relative clustering of Nano-particles in higher weight percentages.
Keywords: Nanocomposite - Aluminum A356 - Hot Press
