- Email: [email protected]
MoS2 hybrid composite
Materials Today: Proceedings xxx (xxxx) xxx
Contents lists available at ScienceDirect
Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr
Investigation of mechanical properties of Al 7075/SiC/MoS2 hybrid composite K. Maruthi Varun ⇑, R. Raman Goud Department of Mechanical Engineering, GRIET, Hyderabad 500092, India
a r t i c l e
i n f o
Article history: Received 25 July 2019 Accepted 9 August 2019 Available online xxxx Keywords: Composite Stir casting Hybrid metal matrix composite Al7075 Silicon carbide Molybdenum disulphide
a b s t r a c t Nowadays, composites are profoundly thriving as the replacement of ferrous alloys. The Aluminum is manifested into great substitute due to their properties like lightweight, low density, high strength, corrosion resistance. The process of fusing the non-ceramics reinforcement like Silicon carbide, Boron carbide, Aluminum oxide, Titanium diboride with a non-metal like Graphite, Molybdenum disulfide or with other non-ceramics to form a hybrid metal matrix composite. In the Present paper, an investigation is carried out on Aluminum 7075 material by process of stir casting where the Silicon Carbide (SiC) with three different weight % (i.e., 3%, 6%, 9%) and Molybdenum Disulphide (MoS2) with 1% constant weight % is added to the base material. Then the tensile test and hardness test were done on a UTM and Rockwell Hardness testing machine respectively for all three prepared materials. As the percentage of SiC is increasing in the material, the hardness value and tensile strength are increasing. The Al7075 + 9%SiC + 1%MoS2 is highest of all. Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 1st International Conference on Manufacturing, Material Science and Engineering.
1. Introduction The Hybrid metal matrix composite is also thriving composite these days where the non-ceramic reinforcements like SiC, B4C, TiC, Al2O3 added to the base metal which could be Aluminum. The introduction of ceramic material into a metal matrix produces a composite material that results in an attractive combination of physical and mechanical properties which cannot be obtained with monolithic alloy [1]. As the name suggests-Hybrid matrix, solid lubricants like Graphite or other non-ceramic are also added to the base metal to enhance the properties to the composite. The addition of soft lubricates into the metal matrix would enhance the wear and anti-frictional properties for the composite. Blending of particular reinforcement into hybrid composite leads in an increase in both mechanical and as well as physical properties with increasing tribological characteristics [2]. These hybrid metal matrix composites were prepared by a few techniques such as diffusion bonding, powder metallurgy, squeeze casting, stir casting, liquid infiltration, and laser composite surfacing [3]. Stir casting
⇑ Corresponding author. E-mail address: [email protected] (K. Maruthi Varun).
is the most advanced techniques to cast the hybrid metal matrix composite material from all above, which results adequate properties to the material. The use of a single reinforced metal matrix which sometimes leads us to deterioration in its properties [3]. For being the solid phase reinforcement, the metal sometimes adapts the quality of brittleness and also the low fraction toughness. The hybrid matrix will come into the picture to add the second solid lubricant matrix like Graphite to enhance the properties of the composites.
2. Literature review Niranjan et al. [1] studied the mechanical properties of Hybrid metal matrix composite (HMMC). The author had prepared the HMMC material using the stir casting process where the base material was Aluminum 6061, and the reinforcements were Silicon carbide (SiC) and Graphite (Gr). The author had cast three different weight percentage of HMMCs material. He retained the SiC composition to 6% throughout the casting and altered the percentage of Graphite composition to 3%, 6%, 9%. Test samples were prepared as per ASTM standards. The specimens were tested under three different conditions, i.e., tensile test, compression test, hardness.
https://doi.org/10.1016/j.matpr.2019.08.131 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 1st International Conference on Manufacturing, Material Science and Engineering.
Please cite this article as: K. Maruthi Varun and R. Raman Goud, Investigation of mechanical properties of Al 7075/SiC/MoS2 hybrid composite, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.131
2
K. Maruthi Varun, R. Raman Goud / Materials Today: Proceedings xxx (xxxx) xxx
The results unveiled the properties of the composites which were compared with other HMMCs as well as with single metal matrix composite- Al 6061 + 6%SiC and also with Al 6061 alloy. The hardness of the prepared single metal matrix composite was higher compared to Al 6061 alloy, whereas the addition of Graphite had decreased the hardness. The tensile test unveiled as the percentage of Graphite in HMMC increased the tensile strength was also increased, so was the result of a compression test. Birari and Shelke [2] had investigated the tribological characteristics of Hybrid composite (HMMC) for defence application. The author had prepared the composites using the stir casting process where Al 7068 was fused with Boron Carbide (B4C) and Graphite (Graphite as he cast the specimens to perform the mechanical tests and wear properties. The first step was to discern the influencing process parameters in wear, which was done by the Taguchi technique. The test was performed on a dry sliding test according to the results of Taguchi analysis and wear test was conducted on a pin on disc apparatus. As the results concluded, the load and reinforcement percentage had improved effect on wear loss and coefficient of friction and also concluded, as the load increase wear and coefficient of friction increase. Revanasidappa et al. [3] had investigated the mechanical and wear behaviour of Al 6061 fused with SiC and Graphite Hybrid metal matrix composite. The specimens were cast using stir casting with varying the SiC weight percentage starting from 3%, 6%, 9%. And Graphite was retained to 1% throughout the casting process. The prepared composites were tested – tensile, compression, hardness, wear testing. The results of these test unveiled that hardness of the composite Al6061-SiC-Gr increased the tensile strength as the increase in the percentage of the SiC in the Hybrid metal matrix composite. So did the strength increased for compression test as well. The wear behaviour of the HMMC material was also improved.
3. Materials selection 3.1. Aluminum 7075 In the class of Aluminum, 7075 is considered as the strongest alloy and a widely used alloy in the automobile industries for the connecting rod, pistons, gear, and so on. The chemical composition of Al 7075 is listed in Table 1. The particular material has very high tensile strength, good fatigue strength, machinability and corrosion is similar to as that of 7075.
3.2. Silicon carbide The Silicon carbide reinforcement is varied by three different weight percentage, i.e. 3%, 6%, and 9%. It is composed of tetrahedral of carbon and silicon atom with strong bond lattice [1]. This composed matrix would help in enhance composite properties like high thermal conductivity, high strength with thermal shock resistant. The composition would increase the brittleness in the composite. It can be formed it a solid phase reinforcement which can be employed as abrasives, ceramics, refractories.
3.3. Molybdenum disulphide Molybdenum disulfide is one of the inorganic compounds which is composed of Molybdenum and Disulfide. It is similar to Graphite, which is also dry lubricant with a low coefficient of friction. The shear strength of Molybdenum disulfide increases with an increase in the coefficient of friction. This is called as superlubricity. The yield strength of the MoS2 depends on the failure mode of the material. It is strain sensitive to the array of the band structure. 4. Sample preparation Fabrication of Composite is the essential and most onerous part of all. The mixture of the alloy and reinforcements in a closed environment with a graphite stirrer from above. The process is called as a stir casting process, one of the economic fabricating process of composition. In the furnace, a small crucible is placed, and inside the crucible, the right amount of raw Aluminum 7075 material is added and heated up to the melting point, which is around 700OC. When the furnace reached up to the melting point, the stirrer will be rotating with a powered motor. Before the addition of material into the crucible, the reinforcements have to be weighed and calculated according to the weight of each Aluminum sample. Silicon Carbide is one of the reinforcements which had to add to the composition. Silicon Carbide is varied into three different weight percentage as of 3% of SiC, 6% of SiC, 9% of SiC, which should be added with respect to that of the Aluminum sample weight. As the stirring process is carrying out the SiC of one of the weight percentage should be warped in an Aluminum foil and drop into the crucible. Then another solid lubricant Molybdenum Disulphide (MoS2) must be added to produce a hybrid metal matrix composite. As of SiC, there is no variation in weight percentage, for all the samples, the weight percentage of MoS2 is constant, which is 1% as that of the weight of the Aluminum. Drop the warped Aluminum foil of MoS2 into the crucible and stir it with the stirrer. The stirring process has to carry out at least for five minutes. After the mixing is completed, the crucible is pulled out by the tongs and the molten state of the composite is poured into a die which already got fixed on the bench wise. Then using the hammer, the specimen is removed from the die and left it for air cooling. The process is then carried out of the other samples as well (see Fig. 1). The prepared Sample are, Al7075 + 3%SiC + 1%Gr Al7075 + 6%SiC + 1%Gr Al7075 + 9%SiC + 1%Gr 5. Experimentation 5.1. Tensile test A tensile test is one of the standard test and most important test to conduct on the specimen, using the machinery known as UTMUniversal Testing Machine. The test is carried out with machining the raw composite into the hour clock shape as per ASTM stan-
Table 1 Chemical composition of Aluminum 7075.
Min Max
Cr
Cu
0.18 0.28
1.2 2
Fe
Mg
0.5
2.1 2.9
Mn 0.3
Si 0.4
Ti
Zn
Al
0.2
5.1 6.1
87.1 91.4
Please cite this article as: K. Maruthi Varun and R. Raman Goud, Investigation of mechanical properties of Al 7075/SiC/MoS2 hybrid composite, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.131
K. Maruthi Varun, R. Raman Goud / Materials Today: Proceedings xxx (xxxx) xxx
3
Fig. 1. (a) Line diagram of Stir casting; (b) Stir Casting Furnace.
Fig. 2. (a) Dimensions for Tensile Specimen; (b) Tensile Specimen.
dards, which is shown below. Then the specimen is clamped between two grippers up to the gripper length. A uniform load is applied from the load cell at a constant rate. This typical test will vet information about the strength of the composite with other value like elongation, strain, stress, proof stress, breaking point (See Fig. 2). A – Length of reduction section, mm G- Gauge length D- Diameter R- Radius of fillet. 5.2. Hardness test Hardness is referred to as the resistance to Indentation. It helps in determining the prement depth of Indentation on the material. A small fixed force is applied to the material using a ball indenter to form an indentation on the material. There different type of test is used to perform the hardness, and one of the tests is the Rockwell Hardness test. Preload of 3Kgf is applied on the material to pierce through the surface in order to reduce the effects of surface finish. Then the Indentation is measured to find the hardness. As the data is given in Brinell’s Hardness test, a conversion is done to change the data from Rockwell to Brinell’s. The test specimen is shown below (See Fig. 3).
Fig. 3. (a) Dimensions for Hardness specimen; (b). Hardness Specimen.
6. Results and discussion 6.1. Tensile test The tensile test provided with a set of graph between stress and strain. The plotted graph is taken with a stack of values used while
the testing is happening. Using the data of load and strain with provided area of the specimen the values of stress is calculated. The strain rate is directly proportional to the elongation of the specimen. The graphs of the three different composition is shown below (See Figs. 4–7, Table 2).
Please cite this article as: K. Maruthi Varun and R. Raman Goud, Investigation of mechanical properties of Al 7075/SiC/MoS2 hybrid composite, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.131
4
K. Maruthi Varun, R. Raman Goud / Materials Today: Proceedings xxx (xxxx) xxx
Fig. 4. Test Values of Al7075 + 3%SiC + 1% MoS2. Fig. 7. Tensile specimen after the break.
Table 2 Tensile Test values of different specimens. S.NO
Composition %W
Tensile Strength (MPa)
1 2 3
Al7075 + 3%SiC + 1%MoS2 Al7075 + 6%SiC + 1%MoS2 Al7075 + 9%SiC + 1%MoS2
184 196 256
Fig. 5. Test Values of Al7075 + 3%SiC + 1% MoS2. Fig. 8. Hardness samples after indentation.
Fig. 6. . Test Values of Al7075 + 9%SiC + 1% MoS2.
6.2. Hardness Data that has been taken from the Rockwell Hardness machine doesn’t have automatic value. The data values are manually noted from the machine. For each specimen three data points have been taken then average of the three calculated. The calculated data is then tabled and charted (See Figs. 8,9 and Table 3.
Fig. 9. Hardness value graph.
Table 3 Hardness Result. S. NO
Composition %W
RHN
1 2 3
Al7075 + 3%SiC + 1%MoS2 Al7075 + 6%SiC + 1%MoS2 Al7075 + 9%SiC + 1%MoS2
74.6 76.8 80.1
Please cite this article as: K. Maruthi Varun and R. Raman Goud, Investigation of mechanical properties of Al 7075/SiC/MoS2 hybrid composite, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.131
K. Maruthi Varun, R. Raman Goud / Materials Today: Proceedings xxx (xxxx) xxx
7. Conclusions The Aluminum 7075 composite is fabricated with Silicon Carbide (SiC) and Molybdenum Disulphide (MoS2) with different weight percentage of SiC – 3%, 6%, 9% and constant weight percentage of MoS2 – 1% using the stir casting process. Then the specimen is investigated under the tensile condition and also with hardness, then data is categorized to find the best composition of all. The Tensile test of Al7075 + 9%SiC + 1%MoS2 has the highest strength than that of all other specimens. The Ultimate strength is given for specimen 3–250 MPa.
5
The hardness value is also increased with increase the weight percentage of SiC, the hardness value is give as 80RHN, from the Rockwell Hardness test. The main advantage of the reinforcement is that the strain rate decreases. References [1] K.N. Niranjan, B.N. Shivaraj, M. Sunil Kumar, A.R. Deepak, IRJET 04 (01) (2007). [2] Rohith Nagabhyrava, Sravan Kota, Aravind Geda, Sri Harsha Gudi, IJMET 08 (05) (2017). [3] V. Balaji, N. Sateesh, M. Manzoor Hussain, Proceeding 2 (2015) 3403–3408.
Please cite this article as: K. Maruthi Varun and R. Raman Goud, Investigation of mechanical properties of Al 7075/SiC/MoS2 hybrid composite, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.131
Contents lists available at ScienceDirect
Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr
Investigation of mechanical properties of Al 7075/SiC/MoS2 hybrid composite K. Maruthi Varun ⇑, R. Raman Goud Department of Mechanical Engineering, GRIET, Hyderabad 500092, India
a r t i c l e
i n f o
Article history: Received 25 July 2019 Accepted 9 August 2019 Available online xxxx Keywords: Composite Stir casting Hybrid metal matrix composite Al7075 Silicon carbide Molybdenum disulphide
a b s t r a c t Nowadays, composites are profoundly thriving as the replacement of ferrous alloys. The Aluminum is manifested into great substitute due to their properties like lightweight, low density, high strength, corrosion resistance. The process of fusing the non-ceramics reinforcement like Silicon carbide, Boron carbide, Aluminum oxide, Titanium diboride with a non-metal like Graphite, Molybdenum disulfide or with other non-ceramics to form a hybrid metal matrix composite. In the Present paper, an investigation is carried out on Aluminum 7075 material by process of stir casting where the Silicon Carbide (SiC) with three different weight % (i.e., 3%, 6%, 9%) and Molybdenum Disulphide (MoS2) with 1% constant weight % is added to the base material. Then the tensile test and hardness test were done on a UTM and Rockwell Hardness testing machine respectively for all three prepared materials. As the percentage of SiC is increasing in the material, the hardness value and tensile strength are increasing. The Al7075 + 9%SiC + 1%MoS2 is highest of all. Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 1st International Conference on Manufacturing, Material Science and Engineering.
1. Introduction The Hybrid metal matrix composite is also thriving composite these days where the non-ceramic reinforcements like SiC, B4C, TiC, Al2O3 added to the base metal which could be Aluminum. The introduction of ceramic material into a metal matrix produces a composite material that results in an attractive combination of physical and mechanical properties which cannot be obtained with monolithic alloy [1]. As the name suggests-Hybrid matrix, solid lubricants like Graphite or other non-ceramic are also added to the base metal to enhance the properties to the composite. The addition of soft lubricates into the metal matrix would enhance the wear and anti-frictional properties for the composite. Blending of particular reinforcement into hybrid composite leads in an increase in both mechanical and as well as physical properties with increasing tribological characteristics [2]. These hybrid metal matrix composites were prepared by a few techniques such as diffusion bonding, powder metallurgy, squeeze casting, stir casting, liquid infiltration, and laser composite surfacing [3]. Stir casting
⇑ Corresponding author. E-mail address: [email protected] (K. Maruthi Varun).
is the most advanced techniques to cast the hybrid metal matrix composite material from all above, which results adequate properties to the material. The use of a single reinforced metal matrix which sometimes leads us to deterioration in its properties [3]. For being the solid phase reinforcement, the metal sometimes adapts the quality of brittleness and also the low fraction toughness. The hybrid matrix will come into the picture to add the second solid lubricant matrix like Graphite to enhance the properties of the composites.
2. Literature review Niranjan et al. [1] studied the mechanical properties of Hybrid metal matrix composite (HMMC). The author had prepared the HMMC material using the stir casting process where the base material was Aluminum 6061, and the reinforcements were Silicon carbide (SiC) and Graphite (Gr). The author had cast three different weight percentage of HMMCs material. He retained the SiC composition to 6% throughout the casting and altered the percentage of Graphite composition to 3%, 6%, 9%. Test samples were prepared as per ASTM standards. The specimens were tested under three different conditions, i.e., tensile test, compression test, hardness.
https://doi.org/10.1016/j.matpr.2019.08.131 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 1st International Conference on Manufacturing, Material Science and Engineering.
Please cite this article as: K. Maruthi Varun and R. Raman Goud, Investigation of mechanical properties of Al 7075/SiC/MoS2 hybrid composite, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.131
2
K. Maruthi Varun, R. Raman Goud / Materials Today: Proceedings xxx (xxxx) xxx
The results unveiled the properties of the composites which were compared with other HMMCs as well as with single metal matrix composite- Al 6061 + 6%SiC and also with Al 6061 alloy. The hardness of the prepared single metal matrix composite was higher compared to Al 6061 alloy, whereas the addition of Graphite had decreased the hardness. The tensile test unveiled as the percentage of Graphite in HMMC increased the tensile strength was also increased, so was the result of a compression test. Birari and Shelke [2] had investigated the tribological characteristics of Hybrid composite (HMMC) for defence application. The author had prepared the composites using the stir casting process where Al 7068 was fused with Boron Carbide (B4C) and Graphite (Graphite as he cast the specimens to perform the mechanical tests and wear properties. The first step was to discern the influencing process parameters in wear, which was done by the Taguchi technique. The test was performed on a dry sliding test according to the results of Taguchi analysis and wear test was conducted on a pin on disc apparatus. As the results concluded, the load and reinforcement percentage had improved effect on wear loss and coefficient of friction and also concluded, as the load increase wear and coefficient of friction increase. Revanasidappa et al. [3] had investigated the mechanical and wear behaviour of Al 6061 fused with SiC and Graphite Hybrid metal matrix composite. The specimens were cast using stir casting with varying the SiC weight percentage starting from 3%, 6%, 9%. And Graphite was retained to 1% throughout the casting process. The prepared composites were tested – tensile, compression, hardness, wear testing. The results of these test unveiled that hardness of the composite Al6061-SiC-Gr increased the tensile strength as the increase in the percentage of the SiC in the Hybrid metal matrix composite. So did the strength increased for compression test as well. The wear behaviour of the HMMC material was also improved.
3. Materials selection 3.1. Aluminum 7075 In the class of Aluminum, 7075 is considered as the strongest alloy and a widely used alloy in the automobile industries for the connecting rod, pistons, gear, and so on. The chemical composition of Al 7075 is listed in Table 1. The particular material has very high tensile strength, good fatigue strength, machinability and corrosion is similar to as that of 7075.
3.2. Silicon carbide The Silicon carbide reinforcement is varied by three different weight percentage, i.e. 3%, 6%, and 9%. It is composed of tetrahedral of carbon and silicon atom with strong bond lattice [1]. This composed matrix would help in enhance composite properties like high thermal conductivity, high strength with thermal shock resistant. The composition would increase the brittleness in the composite. It can be formed it a solid phase reinforcement which can be employed as abrasives, ceramics, refractories.
3.3. Molybdenum disulphide Molybdenum disulfide is one of the inorganic compounds which is composed of Molybdenum and Disulfide. It is similar to Graphite, which is also dry lubricant with a low coefficient of friction. The shear strength of Molybdenum disulfide increases with an increase in the coefficient of friction. This is called as superlubricity. The yield strength of the MoS2 depends on the failure mode of the material. It is strain sensitive to the array of the band structure. 4. Sample preparation Fabrication of Composite is the essential and most onerous part of all. The mixture of the alloy and reinforcements in a closed environment with a graphite stirrer from above. The process is called as a stir casting process, one of the economic fabricating process of composition. In the furnace, a small crucible is placed, and inside the crucible, the right amount of raw Aluminum 7075 material is added and heated up to the melting point, which is around 700OC. When the furnace reached up to the melting point, the stirrer will be rotating with a powered motor. Before the addition of material into the crucible, the reinforcements have to be weighed and calculated according to the weight of each Aluminum sample. Silicon Carbide is one of the reinforcements which had to add to the composition. Silicon Carbide is varied into three different weight percentage as of 3% of SiC, 6% of SiC, 9% of SiC, which should be added with respect to that of the Aluminum sample weight. As the stirring process is carrying out the SiC of one of the weight percentage should be warped in an Aluminum foil and drop into the crucible. Then another solid lubricant Molybdenum Disulphide (MoS2) must be added to produce a hybrid metal matrix composite. As of SiC, there is no variation in weight percentage, for all the samples, the weight percentage of MoS2 is constant, which is 1% as that of the weight of the Aluminum. Drop the warped Aluminum foil of MoS2 into the crucible and stir it with the stirrer. The stirring process has to carry out at least for five minutes. After the mixing is completed, the crucible is pulled out by the tongs and the molten state of the composite is poured into a die which already got fixed on the bench wise. Then using the hammer, the specimen is removed from the die and left it for air cooling. The process is then carried out of the other samples as well (see Fig. 1). The prepared Sample are, Al7075 + 3%SiC + 1%Gr Al7075 + 6%SiC + 1%Gr Al7075 + 9%SiC + 1%Gr 5. Experimentation 5.1. Tensile test A tensile test is one of the standard test and most important test to conduct on the specimen, using the machinery known as UTMUniversal Testing Machine. The test is carried out with machining the raw composite into the hour clock shape as per ASTM stan-
Table 1 Chemical composition of Aluminum 7075.
Min Max
Cr
Cu
0.18 0.28
1.2 2
Fe
Mg
0.5
2.1 2.9
Mn 0.3
Si 0.4
Ti
Zn
Al
0.2
5.1 6.1
87.1 91.4
Please cite this article as: K. Maruthi Varun and R. Raman Goud, Investigation of mechanical properties of Al 7075/SiC/MoS2 hybrid composite, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.131
K. Maruthi Varun, R. Raman Goud / Materials Today: Proceedings xxx (xxxx) xxx
3
Fig. 1. (a) Line diagram of Stir casting; (b) Stir Casting Furnace.
Fig. 2. (a) Dimensions for Tensile Specimen; (b) Tensile Specimen.
dards, which is shown below. Then the specimen is clamped between two grippers up to the gripper length. A uniform load is applied from the load cell at a constant rate. This typical test will vet information about the strength of the composite with other value like elongation, strain, stress, proof stress, breaking point (See Fig. 2). A – Length of reduction section, mm G- Gauge length D- Diameter R- Radius of fillet. 5.2. Hardness test Hardness is referred to as the resistance to Indentation. It helps in determining the prement depth of Indentation on the material. A small fixed force is applied to the material using a ball indenter to form an indentation on the material. There different type of test is used to perform the hardness, and one of the tests is the Rockwell Hardness test. Preload of 3Kgf is applied on the material to pierce through the surface in order to reduce the effects of surface finish. Then the Indentation is measured to find the hardness. As the data is given in Brinell’s Hardness test, a conversion is done to change the data from Rockwell to Brinell’s. The test specimen is shown below (See Fig. 3).
Fig. 3. (a) Dimensions for Hardness specimen; (b). Hardness Specimen.
6. Results and discussion 6.1. Tensile test The tensile test provided with a set of graph between stress and strain. The plotted graph is taken with a stack of values used while
the testing is happening. Using the data of load and strain with provided area of the specimen the values of stress is calculated. The strain rate is directly proportional to the elongation of the specimen. The graphs of the three different composition is shown below (See Figs. 4–7, Table 2).
Please cite this article as: K. Maruthi Varun and R. Raman Goud, Investigation of mechanical properties of Al 7075/SiC/MoS2 hybrid composite, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.131
4
K. Maruthi Varun, R. Raman Goud / Materials Today: Proceedings xxx (xxxx) xxx
Fig. 4. Test Values of Al7075 + 3%SiC + 1% MoS2. Fig. 7. Tensile specimen after the break.
Table 2 Tensile Test values of different specimens. S.NO
Composition %W
Tensile Strength (MPa)
1 2 3
Al7075 + 3%SiC + 1%MoS2 Al7075 + 6%SiC + 1%MoS2 Al7075 + 9%SiC + 1%MoS2
184 196 256
Fig. 5. Test Values of Al7075 + 3%SiC + 1% MoS2. Fig. 8. Hardness samples after indentation.
Fig. 6. . Test Values of Al7075 + 9%SiC + 1% MoS2.
6.2. Hardness Data that has been taken from the Rockwell Hardness machine doesn’t have automatic value. The data values are manually noted from the machine. For each specimen three data points have been taken then average of the three calculated. The calculated data is then tabled and charted (See Figs. 8,9 and Table 3.
Fig. 9. Hardness value graph.
Table 3 Hardness Result. S. NO
Composition %W
RHN
1 2 3
Al7075 + 3%SiC + 1%MoS2 Al7075 + 6%SiC + 1%MoS2 Al7075 + 9%SiC + 1%MoS2
74.6 76.8 80.1
Please cite this article as: K. Maruthi Varun and R. Raman Goud, Investigation of mechanical properties of Al 7075/SiC/MoS2 hybrid composite, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.131
K. Maruthi Varun, R. Raman Goud / Materials Today: Proceedings xxx (xxxx) xxx
7. Conclusions The Aluminum 7075 composite is fabricated with Silicon Carbide (SiC) and Molybdenum Disulphide (MoS2) with different weight percentage of SiC – 3%, 6%, 9% and constant weight percentage of MoS2 – 1% using the stir casting process. Then the specimen is investigated under the tensile condition and also with hardness, then data is categorized to find the best composition of all. The Tensile test of Al7075 + 9%SiC + 1%MoS2 has the highest strength than that of all other specimens. The Ultimate strength is given for specimen 3–250 MPa.
5
The hardness value is also increased with increase the weight percentage of SiC, the hardness value is give as 80RHN, from the Rockwell Hardness test. The main advantage of the reinforcement is that the strain rate decreases. References [1] K.N. Niranjan, B.N. Shivaraj, M. Sunil Kumar, A.R. Deepak, IRJET 04 (01) (2007). [2] Rohith Nagabhyrava, Sravan Kota, Aravind Geda, Sri Harsha Gudi, IJMET 08 (05) (2017). [3] V. Balaji, N. Sateesh, M. Manzoor Hussain, Proceeding 2 (2015) 3403–3408.
Please cite this article as: K. Maruthi Varun and R. Raman Goud, Investigation of mechanical properties of Al 7075/SiC/MoS2 hybrid composite, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.131