Title: Isothermal forging of aluminium based metal matrix composites reinforced with 20% Al2O3 particles

Authors: P. Cavaliere, E. Evangelista

Addresses: Department of Ingegneria dell'Innovazione, University of Lecce,I-70100 Lecce, Italy. ## Department of Mechanics, University of Ancona, I-60131 Ancona,Italy

Abstract: The aim of the present study is the investigation of the hot formability of two aluminium alloys reinforced with 20% Al2O3 particulate in order to develop a technology of isothermal forging for automotive components. The isothermal forging of 6061 and 2618 aluminium alloys reinforced with 20% of Al2O3 particles by hot torsion and hot compression tests was investigated to find out if the formability of these materials can produce defect-free components. The results were used to optimalise and individuate the optimal ||processing window|| in terms of temperature and strain rate following the dynamic material model. The study have analysed the constitutive equations relating flow stress, temperature and strain rates, trying to correlate the mechanical response to the microstructure in terms of damage or microstructural changes of the material such as recovery, static and dynamic recrystallisation, superplastic flow and phase transformations. Optical and electron microscopy (SEM) observations were performed in order to quantify the damage in terms of fracture of the particles and voids formation at the interface between the particles and the matrix. Processing maps were constructed, taking into account torsion and compression tests and the constitutive equations that correlate flow stress, strain rate and temperature in these materials. Laboratory trials were performed and final components were produced by isothermal forging to evaluate the agreement between the model and the production of the individual component. A finite element 2D and 3D code (DEFORMTM) was used to model the behaviour of this material and to predict all mechanical changes during isothermal deformation.

Keywords: damage, FEM, isothermal forgino, metal matrix composites.

DOI: 10.1504/IJMPT.2003.003464

International Journal of Materials and Product Technology, 2003 Vol.19 No.6, pp.443 - 465

Published online: 08 Oct 2003 *

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