Abstracts Book - IMRC 2018

• SD7-P030
MICROSTRUCTURAL ANALYSIS OF ALUMINUM-GRAPHITE
COMPOSITE PREPARED BY MECHANICAL MILLING AND SINTERED
USING AN ALTERNATIVE ROUTE
José Mendoza 1 , Francisco Robles 2 , Carlos Gamaliel Garay Reyes 1 , Ivanovich Estrada 1 , Roberto
Martinez Sanchez 1
1 Centro de Investigación en Materiales Avanzados, S.C., Metalurgia e integridad estructural,
Mexico. 2 University of Houston, Mechanical Engineering Technology, United States.
Aluminum matrix composites are very attractive to automotive and aerospace
industries due to their superior mechanical properties. Not only Mechanical
milling (MM) is an effective technique to disperse hard phases in a ductile matrix,
but also is possible to refine the microstructure of the resulting composite. With
the graphite addition in the aluminum matrix, it is possible to increase the
mechanical properties. This work deals with the composite preparation and the
sintering process. Aluminum (Al) powders with 1wt% of graphite (milled 8 hours)
were mechanical milled in a SPEX 8000M mill for 2 hours to obtain Al-1%Gr
composite. The resulting powders were compacted and sintered following two
routes: Conventional sintering (CS) that involves cold uniaxial compaction (900
MPa) and later the sintering process in a furnace (450°C for 3 hours) under argon
atmosphere high. Meanwhile, the high frequency induction sintering (HFIS)
implicates the compaction (450 MPa) and sintering (450°C for 3 hours)
simultaneously. The effect of the sintering route on the microstructure and
density of composites was evaluated. The microstructural characterization of
samples was carried out through transmission electron microscopy (TEM) and
X-Rays diffraction studies; while the density was determined by Archimedes
method. TEM specimens HFIS and CS were prepared using focused ion
beam. Samples processed by HFIS not only presents higher values of
densification in comparison to CS specimens but also the refined microstructure
is maintained using the alternative route for sintering. Moreover, there is not
presence of aluminum carbide in HFIS samples.
Keywords: aluminum, graphite, induction sintering
Presenting authors email: debos1987@hotmail.com