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D. K. Sharma et al.
1 Introduction
Hardness and wear behavior of lightweight aluminum alloys can be enriched by reinforcement of hard ceramics in the aluminum matrix [1]. Aluminum matrix composites
owned a good combination of mechanical and tribological characteristics and widely
used for structural applications in different sectors like automotive, aerospace, shipbuilding, etc. [2, 3]. Researchers have worked on property enhancement of aluminumbased composites for complex applications since the last few decades. The existence
of brittle ceramics in the soft aluminum matrix decreases ductility and toughness [4].
The ceramic abrasives reinforce only in the surface layers in surface composites, to
preserve the bulk properties along with the advancement of surface properties [5–7].
Generally, the surface properties govern the life of components. The liquid phase
processing methods to produce surface composites like plasma spray, cast sinter,
high energy laser beam, etc., comprise melting which results in undesired interfacial
reactions in reinforcement and the matrix [8, 9]. If surface composites are manufactured in the solid state, below the matrix melting point, the undesired reactions can
be controlled.
The solid state processing technique, friction stir processing (FSP) can be effectively used to manufacture surface composites [10–12], refinement of grains [13,
14], superplasticity [15, 16], fusion weld modification, etc. [17]. FSP has the same
processing principle as the friction stir welding [5, 7]. In the FSP technique, a rotating
tool with a designed pin is inserted into the workpiece under load, followed by
feed along the planned path. The heat generated by the friction between the rotating
shoulder and workpiece plastically deforms the matrix and results in grain refinement
due to dynamic recrystallization [18, 19].
Friction stir processed surface composites have been fabricated by incorporation
of reinforcements in the metallic matrix by different strategies, like hole and groove
methods. In the hole method, the hollow cavities to pack particles are in the form of
series of blind holes [11, 20–24], whereas in the groove method, the cavity is in the
form of one or more groove produced across the workpiece length [25–30]. First, the
cavities are drilled, then particle insertion, compaction, and FSP along the planned
path. First of all, Mishra et al. [5] recognized the FSP method to develop surface
composites containing silicon carbide (SiC) particles in the AA5083 matrix. Many
studies reported effectively manufactured aluminum-based surface composites with
improved hardness and wear characteristics by FSP [6, 23, 24, 27, 31–36]. Gangil
et al. [27] reported enhanced microhardness of friction stir processed AA6063/SiC
surface composite. Saadatmand et al. [33] reported enhanced mechanical and wear
characteristics of friction stir processed Al6061/SiC surface nanocomposites. Similarly, friction stir processed AA5083/SiC displayed improved properties [24]. Mehta
et al. [36] reported enhanced wear resistance of friction stir processed AA6061/B 4 C
surface composites.
This article reports the results of the study about the manufacturing of
AA6061/SiC surface composites using hole and grove method FSP. The effect of the
D. K. Sharma et al.
1 Introduction
Hardness and wear behavior of lightweight aluminum alloys can be enriched by reinforcement of hard ceramics in the aluminum matrix [1]. Aluminum matrix composites
owned a good combination of mechanical and tribological characteristics and widely
used for structural applications in different sectors like automotive, aerospace, shipbuilding, etc. [2, 3]. Researchers have worked on property enhancement of aluminumbased composites for complex applications since the last few decades. The existence
of brittle ceramics in the soft aluminum matrix decreases ductility and toughness [4].
The ceramic abrasives reinforce only in the surface layers in surface composites, to
preserve the bulk properties along with the advancement of surface properties [5–7].
Generally, the surface properties govern the life of components. The liquid phase
processing methods to produce surface composites like plasma spray, cast sinter,
high energy laser beam, etc., comprise melting which results in undesired interfacial
reactions in reinforcement and the matrix [8, 9]. If surface composites are manufactured in the solid state, below the matrix melting point, the undesired reactions can
be controlled.
The solid state processing technique, friction stir processing (FSP) can be effectively used to manufacture surface composites [10–12], refinement of grains [13,
14], superplasticity [15, 16], fusion weld modification, etc. [17]. FSP has the same
processing principle as the friction stir welding [5, 7]. In the FSP technique, a rotating
tool with a designed pin is inserted into the workpiece under load, followed by
feed along the planned path. The heat generated by the friction between the rotating
shoulder and workpiece plastically deforms the matrix and results in grain refinement
due to dynamic recrystallization [18, 19].
Friction stir processed surface composites have been fabricated by incorporation
of reinforcements in the metallic matrix by different strategies, like hole and groove
methods. In the hole method, the hollow cavities to pack particles are in the form of
series of blind holes [11, 20–24], whereas in the groove method, the cavity is in the
form of one or more groove produced across the workpiece length [25–30]. First, the
cavities are drilled, then particle insertion, compaction, and FSP along the planned
path. First of all, Mishra et al. [5] recognized the FSP method to develop surface
composites containing silicon carbide (SiC) particles in the AA5083 matrix. Many
studies reported effectively manufactured aluminum-based surface composites with
improved hardness and wear characteristics by FSP [6, 23, 24, 27, 31–36]. Gangil
et al. [27] reported enhanced microhardness of friction stir processed AA6063/SiC
surface composite. Saadatmand et al. [33] reported enhanced mechanical and wear
characteristics of friction stir processed Al6061/SiC surface nanocomposites. Similarly, friction stir processed AA5083/SiC displayed improved properties [24]. Mehta
et al. [36] reported enhanced wear resistance of friction stir processed AA6061/B 4 C
surface composites.
This article reports the results of the study about the manufacturing of
AA6061/SiC surface composites using hole and grove method FSP. The effect of the