Young's modulus of Al/SiC P/MgAl2O4 composites with different particle size distribution of reinforcements

• Autor(a) principal: Montoya-Dávila,M.
• Data de Publicação: 2010
• Outros Autores: Pech-Canul,M.I., Escalera-Lozano,R., Pech-Canul,M.A.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Matéria (Rio de Janeiro. Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1517-70762010000200021
• topic: Al/SiCp/MgAl2O4 composites; multimodal distribution; Young's modulus

The effect of particle size distribution of SiC particulate reinforcements coated with colloidal SiO2 on Young´s modulus of Al/SiCp/MgAl2O4 composites fabricated by reactive infiltration was investigated. Composites were prepared from porous preforms of silica-coated α- SiC powders of 10, 54, 86, and 146 μm, 0.6 volume fraction of reinforcements and particle size distribution from monomodal to cuatrimodal. Infiltration tests with the alloy Al-13.3Mg-1.8Si (wt. %) were carried out in Ar→N2 atmosphere at 1100ºC for 60 min. The composites were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). In addition to density and residual porosity measurements, Young´s modulus was evaluated by ultrasonic techniques. Results show that with increase in particles size distribution, residual porosity decreases and density and Young´s modulus of the composites are improved, the latter from 185.39 ±3.6 to 201.93 ±2.3 GPa. This is attributed to the increased metal-ceramic interfaces and to an enhanced matrix-reinforcement load transmission.