ROLLING BEHAVIOUR OF ALUMINUM ALLOY 2014-10wt% SiCp
METAL MATRIX COMPOSITES
Ajay Kumar P.
1
, Gajendra Dixit
2
, Aruna Patel
3
, S. Das
4
1
Department of Materials Science and Engineering, University of Wisconsin-Milwaukee,
Milwaukee, WI 53211 USA
2
Department of Mechanical Engineering, Maulana Azad National Institute of Technology,
Bhopal 462003, India
3
Advanced Materials and Processes Research Institute (AMPRI) CSIR, Bhopal 462026, India
4
Department of Materials Science and Engineering, Indian Institute of Technology, Kanpur
208016, India
Keywords: Metal matrix composite, Mechanical properties, Ceramic particles, Deformation
Abstract
Hot deformation behaviour of 10wt% SiCp reinforced 2014 Al alloy cast composite is studied
by hot rolling process at varying rolling speed 3-7m/min at a temperature of 400
o
C. During
rolling operation, the material is deformed with strain rates of 2-3 s
-1
. It is observed that the
hardness of the Al-SiCp composite material decreases with increasing rolling passes. This
happens mainly due to softening of the material. Fracturing of SiCp particles are observed after
65-73% deformations and the dynamic recrystallization and superplasticity are seen under high
deformation. The SiCp particles in the Al MMCs flow along with the grains and Al phase is
always around the SiCp particles. This is possible only when the material gets softer at higher
temperature i.e. at 400
o
C. A detailed microstructural examination indicates that different
deformation mechanisms such as dynamic recrystallization, void formation, flow localization,
and superplasticity are present.
1. Introduction
Composite materials are more suitable than conventional materials as they have favourable
mechanical and thermal properties. Composites containing discontinuous reinforcement,
especially particulate metal-matrix composites have found commercial applications [1-3] since
they can be produced economically by conventional processing techniques. Among these
materials, aluminium-alloy-based composites are very attractive because of their processing
flexibility, wide range, low density, high wear resistance, high thermal conductivity, heat-
treatment capability and improved elastic modulus and strength. Various methods have been
developed to produce metal-matrix composites. An economical way of producing metal-matrix
composites is the incorporation of particles into the liquid metal in casting process. In as-cast
aluminum-alloy-based composites, a moderate improvement in strength over the unreinforced
alloys is obtained. On the other hand, when the particulate reinforcement is added to improve
stiffness, strength and tribological properties, a substantial decrease in ductility is observed.
Inferior ductility of these materials limits their performance and applications [4]. The ductility
is affected by several factors such as the matrix microstructure, heterogeneous reinforcement
distribution [5, 6], porosity content and strength of the interfacial bond between the matrix and
the reinforcement. It has been shown that some improvement in ductility as well as strength is
observed by applying pressure during solidification [7], by optimizing the heat treatment
parameters of the matrix [8] and with the application of plastic forming processes to the
composites [9-14]. Forming processes alter the structural parameters, which influence the
1296
Contributed Papers from Materials Science and Technology 2018 (MS&T18)
October 14–18, 2018, Greater Columbus Convention Center, Columbus, Ohio, USA
Copyright © 2018 MS&T18®
DOI 10.7449/2018/MST_2018_1296_1303