The Tribological Behavior of an In-Situ Processed Magnesium …
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and thereby attempting to enhance both the mechanical properties and tribological
behavior [14–16].
Tribological behavior of the material is mostly influenced by its operating conditions like (i) sliding speed, (ii) sliding distance, (iii) applied load and (iv) mechanical
properties of the materials [17, 18]. Nguyen and co-workers developed AZ31B/Al 2 O 3
composite and investigated its tribological behavior at different operating conditions.
It was noticed that the composite material revealed excellent wear resistance properties at a higher sliding speed with a lower applied load. Delamination of the surface
materials occurred at the sliding speed of 1 and 3 m/s, and for a load of 10 and 30 N.
At the higher speed (more than 5 m/s for 10 N and 3 m/s for 30 N) thermal softening at the contact surface was observed [19]. Habibnejad-Korayem and co-workers
strengthened both pure magnesium and the AZ31 magnesium alloy by reinforcing
it with nanoparticles of aluminum oxide (Al 2 O 3 ) and then analysing its tribological
properties. Addition of aluminum oxide (Al 2 O 3 ) nanoparticles to the magnesium
alloy matrix enhanced the properties like hardness and strength through a refinement
in the grain size. This helped in improving the wear resistance properties of the
chosen composite material [20]. Sahoo and co-workers studied the wear behavior of
AZ91/TiC-TiB 2 in-situ composites and observed both the abrasion wear and oxidation wear to occur at a loading condition of 10–20 N with a sliding speed of 0.5 and
1.0 m/s. At the same time, surface melting was noticed at a load of 50 N and sliding
speed of 2 m/s [21].
Addition of graphite to the magnesium alloy metal matrix enhances the wear
resistance as it acts as a solid lubricant on the contact surface. Further, the addition of graphite reduces the mechanical properties of the chosen composite material
like hardness, tensile strength and flexural strength [22]. To overcome this drawback, Aatthisugan and co-workers reinforced the chosen magnesium alloy with both
graphite and boron carbide (B 4 C) to form a hybrid magnesium matrix composite.
In this case, the combination of reinforcements enhances the wear resistance significantly while boron carbide (B 4 C) helps to enhance the mechanical properties. Ultimately, the hybrid composite material offered improved strength and enhanced wear
resistance [23]. Researchers also noticed that unlike graphite, boron nitride (BN) also
acts as a solid lubricant, which improves the wear resistance. Kaviti and co-workers
noticed that addition 0.5 weight percent of BN nanoparticles to magnesium enhances
the wear resistance and reduces the coefficient of friction. Further, addition of boron
nitride (BN) nanoparticles reduces the wear resistance [24]. Xiao and co-workers
reinforced titanium diboride (TiB 2 ) particles to the AZ91 magnesium alloy with the
intent of enhancing the wear resistance properties. Presence of titanium diboride
(TiB 2 ) in the chosen AZ91 magnesium alloy matrix acts as a grain refiner while
concurrently providing resistance to plastic deformation. From the morphology of
the worn surface, it was observed that both the rate of delamination and surface roughness increase with an increase in applied load. In the cross-section of the wear surface
of the AZ91 magnesium alloy few cracks were noticed, whereas for the AZ91/TiB 2
composites, no cracks were observed as presence of the reinforcing titanium diboride
(TiB 2 ) particles aids in arresting the cracks [25].
77
and thereby attempting to enhance both the mechanical properties and tribological
behavior [14–16].
Tribological behavior of the material is mostly influenced by its operating conditions like (i) sliding speed, (ii) sliding distance, (iii) applied load and (iv) mechanical
properties of the materials [17, 18]. Nguyen and co-workers developed AZ31B/Al 2 O 3
composite and investigated its tribological behavior at different operating conditions.
It was noticed that the composite material revealed excellent wear resistance properties at a higher sliding speed with a lower applied load. Delamination of the surface
materials occurred at the sliding speed of 1 and 3 m/s, and for a load of 10 and 30 N.
At the higher speed (more than 5 m/s for 10 N and 3 m/s for 30 N) thermal softening at the contact surface was observed [19]. Habibnejad-Korayem and co-workers
strengthened both pure magnesium and the AZ31 magnesium alloy by reinforcing
it with nanoparticles of aluminum oxide (Al 2 O 3 ) and then analysing its tribological
properties. Addition of aluminum oxide (Al 2 O 3 ) nanoparticles to the magnesium
alloy matrix enhanced the properties like hardness and strength through a refinement
in the grain size. This helped in improving the wear resistance properties of the
chosen composite material [20]. Sahoo and co-workers studied the wear behavior of
AZ91/TiC-TiB 2 in-situ composites and observed both the abrasion wear and oxidation wear to occur at a loading condition of 10–20 N with a sliding speed of 0.5 and
1.0 m/s. At the same time, surface melting was noticed at a load of 50 N and sliding
speed of 2 m/s [21].
Addition of graphite to the magnesium alloy metal matrix enhances the wear
resistance as it acts as a solid lubricant on the contact surface. Further, the addition of graphite reduces the mechanical properties of the chosen composite material
like hardness, tensile strength and flexural strength [22]. To overcome this drawback, Aatthisugan and co-workers reinforced the chosen magnesium alloy with both
graphite and boron carbide (B 4 C) to form a hybrid magnesium matrix composite.
In this case, the combination of reinforcements enhances the wear resistance significantly while boron carbide (B 4 C) helps to enhance the mechanical properties. Ultimately, the hybrid composite material offered improved strength and enhanced wear
resistance [23]. Researchers also noticed that unlike graphite, boron nitride (BN) also
acts as a solid lubricant, which improves the wear resistance. Kaviti and co-workers
noticed that addition 0.5 weight percent of BN nanoparticles to magnesium enhances
the wear resistance and reduces the coefficient of friction. Further, addition of boron
nitride (BN) nanoparticles reduces the wear resistance [24]. Xiao and co-workers
reinforced titanium diboride (TiB 2 ) particles to the AZ91 magnesium alloy with the
intent of enhancing the wear resistance properties. Presence of titanium diboride
(TiB 2 ) in the chosen AZ91 magnesium alloy matrix acts as a grain refiner while
concurrently providing resistance to plastic deformation. From the morphology of
the worn surface, it was observed that both the rate of delamination and surface roughness increase with an increase in applied load. In the cross-section of the wear surface
of the AZ91 magnesium alloy few cracks were noticed, whereas for the AZ91/TiB 2
composites, no cracks were observed as presence of the reinforcing titanium diboride
(TiB 2 ) particles aids in arresting the cracks [25].