and kept at the maximum load for 500 s then unloaded [7, 12, 14]. Scratch testing capability of a nano-indenter was utilized to
perform relatively fast wear tests to compare the wear behaviour of the different samples. Wear tests were conducted by a
conical tip with a 90
cone angle. Tests were run under a normal load of 20 mN applied over a linear track of 500 nm for
50 cycles.
3.3 Results and Discussion
3.3.1 Microstructure and Mapping Analyses of the Compositions Produced by “Sintering
and Sinter + Forging Process
Figure 3.1a shows the microstructure taken from a sintered + forged specimen with “EDS” chemical analysis obtained on the
SEM with (BSE) Back Scattered option. At the left side, a general microstructure was given for the sintered forging specimen.
At the right side a special zone highlighted a typical chemical bonding diffusion mutually between the matrix and the
reinforcements. In a general way, a homogeneous structure with distribution of the reinforcements in regular way in the matrix
and very tough interface between the reinforcements and matrix due to a good chemical bonding diffusion at interface of
matrix-reinforcement thanks to combined process sinter + forging. Additionally, copper help so much by making a very easily
diffusion in the matrix. It seems also well the effect of the other reinforcements, particularly the effect of SnO 2 on the diffusion
bonding at the interface between the matrix and the reinforcements. Addition of these reinforcements in the composite
increase the toughening mechanism of the composite.
In fact, this is an advantage to add copper and γ-alumina together for this type of the composite because the copper increase
also the wettability of the reinforcement in the matrix mainly γ-alumina and Mo, etc., this is a useful property for industrial
application during manufacturing of the complex hybrid component parts. For this reason, the combined process (Sinter +
Forging) can be very benefit to create a very tough and sound microstructure of the hybrid composites.
For a detail evaluation of the microstructure, mapping elementary analyse has been carried out on the certain specimens
that this type of analyse give a safety observation on the homogeneous structure, the distribution of the reinforcements as very
fine particles in micro size, etc.
Composite for “ALO” hybrid composite produced by combined process; Sinter + Forging show the distribution of the
reinforcements in the microstructure as indicated in the Fig. 3.1b. Evidently recycled Alumix-123 chips were used in this work
even if they were atomized before preparing the composite, certain size of the chips keep their sizes that are very variable
between 20 and 50 μm measured on the specimens produced under laboratory conditions. For this reason, the combined
process “sinter + forging” should help and improve the distribution of reinforcements in the final structure homogenously.
That is reason we privilege this process especially for the recycled constituents as a low cost, alternative manufacturing
process to design the composite [4, 7, 12, 14].
3.3.2 Static Compression and 3-Point Bending Test Results
First of all, for the design of a hybrid composite from fresh scrap recycled constituents can be useful for the engineering parts
as low cost manufacturing. Truly, “sintered + forging” process is called as near and/or quasi near-net shape process for the
manufacturing of the pieces processed from fresh scrap materials [4, 7, 12, 14].
Primarily, this process is used for bulk materials in industrial applications. In fact, low-cost sinter-forging approach for the
processing of the fine particle-reinforced metal matrix composites gives always high performance applications of the
industrial pieces (fatigue-creep, static and impact compression, 3P-bending, etc.). In the present work, a simple static
compression and 3-point bending (3 PB) test results have been analyzed under the laboratory scales to evaluate the mechanical
behaviour of these hybrid composites produced with sintering and also sinter + forging processes.
This manufacturing process should be used very well on the many other composites in the industrial scale. It means that
very tough and strong pieces can be obtained with this combined process but cheaper regarding to the other manufacturing
processes that they are actually proposed in the literature.
Figure 3.2 gives these static compression test results obtained on the specimens produced by sintering and sinter + Forging
processes for the “ALO” hybrid composite. All other compression test results obtained for the combined method sintered
forging process were compared with those obtained only sintering process.
3 Design of Recycled Alumix-123 Based Composites Reinforced. . .
11
perform relatively fast wear tests to compare the wear behaviour of the different samples. Wear tests were conducted by a
conical tip with a 90
cone angle. Tests were run under a normal load of 20 mN applied over a linear track of 500 nm for
50 cycles.
3.3 Results and Discussion
3.3.1 Microstructure and Mapping Analyses of the Compositions Produced by “Sintering
and Sinter + Forging Process
Figure 3.1a shows the microstructure taken from a sintered + forged specimen with “EDS” chemical analysis obtained on the
SEM with (BSE) Back Scattered option. At the left side, a general microstructure was given for the sintered forging specimen.
At the right side a special zone highlighted a typical chemical bonding diffusion mutually between the matrix and the
reinforcements. In a general way, a homogeneous structure with distribution of the reinforcements in regular way in the matrix
and very tough interface between the reinforcements and matrix due to a good chemical bonding diffusion at interface of
matrix-reinforcement thanks to combined process sinter + forging. Additionally, copper help so much by making a very easily
diffusion in the matrix. It seems also well the effect of the other reinforcements, particularly the effect of SnO 2 on the diffusion
bonding at the interface between the matrix and the reinforcements. Addition of these reinforcements in the composite
increase the toughening mechanism of the composite.
In fact, this is an advantage to add copper and γ-alumina together for this type of the composite because the copper increase
also the wettability of the reinforcement in the matrix mainly γ-alumina and Mo, etc., this is a useful property for industrial
application during manufacturing of the complex hybrid component parts. For this reason, the combined process (Sinter +
Forging) can be very benefit to create a very tough and sound microstructure of the hybrid composites.
For a detail evaluation of the microstructure, mapping elementary analyse has been carried out on the certain specimens
that this type of analyse give a safety observation on the homogeneous structure, the distribution of the reinforcements as very
fine particles in micro size, etc.
Composite for “ALO” hybrid composite produced by combined process; Sinter + Forging show the distribution of the
reinforcements in the microstructure as indicated in the Fig. 3.1b. Evidently recycled Alumix-123 chips were used in this work
even if they were atomized before preparing the composite, certain size of the chips keep their sizes that are very variable
between 20 and 50 μm measured on the specimens produced under laboratory conditions. For this reason, the combined
process “sinter + forging” should help and improve the distribution of reinforcements in the final structure homogenously.
That is reason we privilege this process especially for the recycled constituents as a low cost, alternative manufacturing
process to design the composite [4, 7, 12, 14].
3.3.2 Static Compression and 3-Point Bending Test Results
First of all, for the design of a hybrid composite from fresh scrap recycled constituents can be useful for the engineering parts
as low cost manufacturing. Truly, “sintered + forging” process is called as near and/or quasi near-net shape process for the
manufacturing of the pieces processed from fresh scrap materials [4, 7, 12, 14].
Primarily, this process is used for bulk materials in industrial applications. In fact, low-cost sinter-forging approach for the
processing of the fine particle-reinforced metal matrix composites gives always high performance applications of the
industrial pieces (fatigue-creep, static and impact compression, 3P-bending, etc.). In the present work, a simple static
compression and 3-point bending (3 PB) test results have been analyzed under the laboratory scales to evaluate the mechanical
behaviour of these hybrid composites produced with sintering and also sinter + forging processes.
This manufacturing process should be used very well on the many other composites in the industrial scale. It means that
very tough and strong pieces can be obtained with this combined process but cheaper regarding to the other manufacturing
processes that they are actually proposed in the literature.
Figure 3.2 gives these static compression test results obtained on the specimens produced by sintering and sinter + Forging
processes for the “ALO” hybrid composite. All other compression test results obtained for the combined method sintered
forging process were compared with those obtained only sintering process.
3 Design of Recycled Alumix-123 Based Composites Reinforced. . .
11