Efecto de las partículas de refuerzo en las propiedades del material compuesto A6061/Al2o3p

Resumen

An aluminium alloy A6061 reinforced with particles of alumina (A6061/Al2O3p), with average particle size of 13,8 Micm, has been studied. This composite was obtained by stir casting, using the Duralcan process. The cast ingot was extruded and hot forged. In order to optimize the forging process in components obtained in one and two stages, the microstructure, mechanical properties and damage mechanisms were studied under different temperatures and as well as deformation velocities. Microstructural analysis was conducted on A6061 and A6061/Al2O3p cast ingot and extruded billet with the aim of knowing the effect of addition of reinforced particles and the extrusion process on the microstructure of the composite. The results showed the formation of a MgAl2O4 compound, spinel type, which cover the reinforcement particles, as product of the reaction between the Al2O3 particles and the matrix during the stir casting process. Also, the porous and defects presented in the matrix¿]particle interface produced a decrement of the mechanical resistance of the ingot due to an inefficient load transfer from the matrix to the reinforcement material. However, the last can be improved by means of a heat treatment or a forged process both at high temperature, which increase the adherence between the matrix and ceramic particles producing notable enhanced mechanical properties. For confirming the above mentioned, a rear wheel hub of an automobile was fabricated under the optimized process, showing a better homogenization of the material and an improvement of the mechanical properties. Also, a more uniform distribution of the reinforcement particles was observed. It is confirmed, too, a more significant increment of the component quality obtained in one stage than in two stages because of a damage reduction produced in the process.