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B. K. Shivananda ¹, Madeva Nagaral ², D. Madhu ³, V. Auradi ⁴

Affiliations
1 Mechanical Engineering, UVCE, Bangalore, Karnataka, IN
2 Aircraft Research and Design Centre, HAL, Bangalore, Karnataka, IN
3 Mech. Engg., Sri Nandhanam College of Engg. & Tech, Tirupattur, Tamilnadu, IN
4 R&D Centre, Mechanical Engineering, SIT, Tumkur, Karnataka, IN

Abstract

The present work, aims at investigating the wear properties of AA2024 alloy before and after introducing micro size Boron Carbide (B₄C) particulates. B₄C particulate reinforced AA2024 alloy metal matrix composites were prepared by stir casting method. Weight fraction of the reinforcement was varied 0 to 6 wt. % of B₄C in steps of 3 wt. %. For each composite, during processing the reinforcement particles were pre-heated to a temperature of 400°C and then dispersed into the vortex of molten AA2024 alloy. The micostructural characterization was done using scanning electron microscope, which revealed uniform distribution of B₄C particles in Al matrix. Pin-on-disc wear testing machine was used to evaluate the wear of prepared specimens, in which a hardened EN32 steel disc was used as the counter face. The results revealed that the wear in terms of height loss was increased with increase in normal load and sliding speed for all the conditions. Further, wear studies also suggest that wear resistance of the AA2024-3 & 6 wt. % B₄C composites was lesser than that of the AA2024 matrix.

Keywords

AA2024 Alloy, B₄C, Stir Casting, Hardness, Tensile Strength.

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Shivraj Koti ¹, S. B. Halesh ¹, Madeva Nagaral ², V. Auradi ³

Affiliations
1 Department of Mechanical Engineering, Sir MVIT, Bangalore, Karnataka, IN
2 Aircraft Research and Design Centre, HAL, Bangalore, Karnataka, IN
3 R&D Centre, Department of Mechanical Engineering, SIT, Tumkur, Karnataka, IN

Abstract

The work is carried out to investigate and study the mechanical properties of B₄C reinforced AA7475 alloy metal matrix composites. In the present work AA7475 alloy is taken as the base matrix and B₄C particulates as reinforcement material to prepare metal matrix composites by stir casting method. For metal matrix composites the reinforcement material was varied from 0 to 4 wt. % in steps of 2 wt. %. For each composite, the reinforcement particulates were preheated to a temperature of 300°C and dispersed into a vortex of molten AA7475 alloy. The microstructural characterization was done using scanning electron microscope. Mechanical properties like hardness, ultimate tensile strength and yield strength were evaluated as per ASTM standards. Further, scanning electron microphotographs revealed that there was uniform distribution of B₄C particulates in AA7475 alloy matrix. Hardness, ultimate tensile strength and yield strength increased as wt. % of B₄C increased in the base matrix.

Keywords

AA7475 Alloy, B₄C, Stir Casting, Hardness, Tensile Strength.

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J. S. Amarnath ¹, Chris Edberg ¹, G. R. Bharath ¹, B. R. Girish ¹, G. L. Chandrasekhar ¹, Madeva Nagaral ²

Affiliations
1 Mechanical Engineering, MVJ College of Engineering, Bangalore, Karnataka, IN
2 ARDC, Hindustan Aeronautics Limited, Bangalore, Karnataka, IN

Abstract

Aluminium hybrid composites are a new generation of metal matrix composites that have the potentials of satisfying the recent demands of advanced engineering applications. These demands are met due to improved mechanical properties, amenability to conventional processing technique and possibility of reducing production cost of aluminium hybrid composites. Present work is investigating the effects of adding SiC and Graphite particulates to Al-4.5% Cu alloy in the mechanical properties of the composites.The Al-4.5% Cu alloy reinforced with 6 wt. % SiC and 6 wt. % of Graphite particulates composites were fabricated by stir casting method. Microstructure and mechanical properties such as hardness and ultimate tensile strength, yield strength were examined. Microstructure of the samples has been investigated by using optical microscope to know the uniform distribution of reinforcement particulates in the matrix. It was abserved that the hardness, ultimate tensile strength and yielding strength of the Al-4.5% Cu alloy increased with the addition of 6 wt. % of SiC and Graphite particulates.

Keywords

Al-4.5% Cu Alloy, SiC, Graphite, Stir Casting, Hardness, Tensile Behavior.

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B. R. Chandrashekar ¹, A. M. Prakash ², K. S. Badarinarayan ¹, Madeva Nagaral ³, H. N. Reddappa ⁴

Affiliations
1 Department of Mechanical Engineering, MS Engineering College, Bangalore, IN
2 Department of Mechanical Engineering, MSCE, Bangalore, IN
3 Aircraft Research and Design Centre, Bangalore, IN
4 Department of Mechanical Engineering, BIT, Bangalore, IN

Abstract

The work is carried out to investigate and study the hardness and wear properties of b₄c reinforced al-7si-1mg alloy metal matrix composites. in the present work al-7si-1mg alloy is taken as the base matrix and b₄c particulates as reinforcement material to prepare metal matrix composites by stir casting method. for metal matrix composites the reinforcement material was taken 5 wt. %. the reinforcement particulates were preheated to a temperature of 600°c and dispersed into a vortex of molten al-7si-1mg alloy the microstructural characterization was done using scanning electron microscope. properties like hardnessand wear were evaluated as per astm standards. further, scanning electron microphotographs revealed that there was uniform distribution of b₄c particulates in al-7si-1mg alloy matrix. hardness and wear resistance of al-7si-1mg and b₄c composites were increased as compared to base alloy.

Keywords

Al-7Si-1Mg Alloy, B₄C, Hardness, Stir Casting, Metal Matrix Composites.

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Revanna K. ¹, Suresh R. ², Madeva Nagaral ³, Vasanth kumar H.S. ⁴

Affiliations
1 Department of Mechanical Engineering, Government Engineering College, Chamarajanagara 571313, VTUCPGS, Mysuru 570037, IN
2 Department of Mechanical Engineering, VTU-CPGS, Mysuru 570037, IN
3 Aircraft Research and Design Centre, Hindustan Aeronautics Limited, Bengaluru 560037, IN
4 Department of Mechanical Engineering, Government Engineering College, Kushalanagar 571234, Karnataka, IN

Abstract

Aluminium metal matrix composites (AMMCs) gained an extensive popularity in different engineering fields monotonically due to their enhanced mechanical properties when compared to traditional monolithic metals. In the present investigation composites were produced using liquid metallurgy technique with modified stir casting approach with bottom pouring arrangement. Al 2214 aluminium composites have been successfully prepared with various percentage (viz. 0, 1.5, 3, 4.5, 6) of graphite reinforcement and their physical and wear behaviour have been analyzed. The experiment revealed that the amount of graphite in the matrix increased and the density reduces, hardness decreases beyond 1.5% of graphite, ultimate tensile strength and wear resistance of composites improved with increased addition of reinforcement. Optical microscope and energy dispersive X-ray (EDX) results shows uniform distribution and confirmed the existence of graphite particles in Al 2214 matrix phase

Keywords

Al2214 alloy, graphite, tensile strength, microstructure, wear.

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Shanawaz Patil ¹, Manjunath L H ¹, A. A. Pasha ², Madeva Nagaral ³

Affiliations
1 School of Mechanical Engineering, REVA University, Bengaluru 560 064, IN
2 Aerospae Engineering Department, King Abdulaziz University, Jeddah 21589, SA
3 Aircraft Research and Design Centre, HAL, Bangalore-560037, Karnataka, IN

Abstract

The effect of beryl particles and graphene nano platelets (GNPs) on the wear behaviour of Al7075-beryl-graphene hybrid composites has been studied. The hybrid composites were developed containing Al7075 matrix as matrix materials and 6 weight percentage of beryl and varying 0.5 to 2 weight percentage of graphene by using novel two step stir casting technique and wear behaviour of the newly developed hybrid composites were studied. The dry sliding wear studies conducted using a pin-on-disc tribo-tester under atmospheric conditions revealed that the wear loss of Al7075-beryl-graphene hybrid composites are lower than that of the matrix Al7075 alloy and further with increasing weight percentage of graphene decreased the wear loss of the hybrid composites. The wear studies also showed that the increase in load, sliding speed and sliding distance, the wear loss of the composites increased. The microstructure of the worn out surface revealed that a huge amount of plastic deformation appeared on the unreinforced Al7075 alloy when compared to the reinforced hybrid composites. The incorporation of beryl and graphene into Al7075 showed worn out surface that is not smooth and grooves, scratches and parallel lines were observed. The addition of beryl and GNPs into the matrix reduces erosion and small grooves like structure were noticed in the hybrid composites which leads to a reduction in wear in Al7075-beryl-GNPs hybrid composites

Keywords

Al7075, beryl, graphene, microstructure, wear

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Madeva Nagaral ¹, V Auradi ², Shanawaz Patil ³, Bharath V ⁴, Nagaraj N ⁵

Affiliations
1 Aircraft Research and Design Centre, HAL, Bangalore 560037, IN
2 Department of Mechanical Engineering, Siddaganga Institute of Technology, Tumkur 572103, IN
3 School of Mechanical Engineering, Reva University, Bangalore 560064, IN
4 Department of Mechanical Engineering, KNS Institute of Technology, Bangalore, IN
5 Department of Mechanical Engineering, APS Polytechnic, Bangalore, Karnataka, IN

Abstract

In the present research, the effect of micron sized graphite addition on the microstructure and wear behaviour of Al6061 alloy has been studied. The Al6061 alloy metal matrix composites reinforced with 6, 9 and 12 varying wt.% of graphite particles were fabricated by novel two step stir cast route which helps in improving the wettability of Al6061 alloy matrix with graphite particles. The created composites were exposed to microstructural studies and wear properties evaluation. Microstructural characterizations of achieved samples were carried out by SEM microscopy, EDS and XRD patterns. The occurrence of graphite particles were confirmed by the XRD patterns. The wear behaviour of Al6061 alloy with 6, 9 and 12 weight percentages of graphite composites were evaluated using pin on disc wear apparatus. All the experiments were conducted by varying applied loads of 1, 3 and 5 kg at 400 rpm sliding speed and varying sliding speeds of 100, 200, 400 and 600 rpm at 5 kg constant load. Wear mechanisms were studied by using SEM micrographs of worn surfaces and wear debris.

Keywords

Al6061 alloy, graphite particles, microstructure, wear, worn surface, wear debris

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Akanksh V N ¹, Pranav Hegde ¹, Siddharth S ¹, Manjunath A B ¹, C Siddaraju ², Madeva Nagaral ³

Affiliations
1 UG Student, Department of Mechanical Engineering, Ramaiah Institute of Technology, IN
2 Assistant Professor, Department of Mechanical Engineering, Ramaiah Institute of Technology, IN
3 Deputy Manager, Aircraft Research and Design Centre, Hindustan Aeronautics Limited Bangalore, Karnataka 560054, IN

Abstract

Metal matrix composite plays an important role in automobile and aerospace applications. Among all the metals, aluminium is considered as the lighter metal. In present investigation aluminium-2024 is considered as the base alloy and reinforced with boron carbide to increase its hardness. Aluminium metal matrix composite is obtained by combining different percentage of boron carbide particulates in the volume fraction 2.5 wt.% and 5 wt.%. Synthesis is done by stir casting technique and the characterization is carried out using scanning electron microscope. The properties of Al2024 reinforced with boron carbide is evaluated by using tensometer, pin on disc wear testing machine and vickers hardness tester. With the increase in the reinforcement high hardness, tensile strength and higher wear resistance is achieved. These types of MMCs are widely used in automobile and aerospace applications due to their great mechanical behaviours, low density, low factor of thermal expansion; corrosion resistance is better and increased wear resistance as compared to conventional metals and alloys. Improved mechanical property of these composites makes them very useful for various applications in many areas from technological point of view.

Keywords

Microstructure, mechanical and wear behaviour, composite technology, AL2024–B4C

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Kotresha Mydur ¹, Mahendra Kumar S ¹, Madeva Nagaral ², Bharath V ³, V Auradi ⁴

Affiliations
1 Department of Mechanical Engineering, RV College of Engineering, Bangalore-560074, Visvesvaraya Technological University, Karnataka, IN
2 Aircraft Research and Design Centre, Hindustan Aeronautics Limited, Bangalore 560037, Karnataka, IN
3 Department of Mechanical Engineering, RNS Institute of Technology, Bangalore-560098, Visvesvaraya Technological University, Karnataka, IN
4 Department of Mechanical Engineering, Siddaganaga Institute of Technology, Tumakuru- 572103, Visvesvaraya Technological University, Karnataka,, IN

Abstract

In the current studies an investigations were made to know the effect of 20 to 25 micron sized B4C particles addition on the physical and mechanical behaviour of Al7010 alloy metal composites. Al7010 alloy with 4 and 8 wt.% of B4C composites were produced by stir cast process. These synthesized composites were tested for numerous mechanical properties like hardness and tensile behaviour along with density measurements. Further, microstructural characterization was carried by SEM and XRD analysis to know the micron sized particles distribution and phases. By adding 20 to 25 micron sized B4C particles hardness and tensile strength of Al7010 alloy was enriched with slight decrease in elongation. Further, density of Al7010 alloy was decreased with the accumulation of B4C particles. Various tensile fracture behaviours were observed by SEM analysis.

Keywords

Al7010 Alloy, B4C, Microstructure, Hardness, Tensile Behaviour, Fractography.

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Nagaraj N ¹, Mahendra K V ², Madeva Nagaral ³, Bharath V ⁴, V Auradi ⁵, Subbaraya Mohan Kumar ⁶

Affiliations
1 Department of Mechanical Engineering, APS Polytechnic, Bangalore, IN
2 Department of Mechanical Engineerg, Raja Reddy Institute of Technology, Bangalore, IN
3 Aircraft Research and Design Centre, HAL, Bangalore, IN
4 Department of Mechanical Engineerg, RNS Institute of Technology, Bangalore, IN
5 Department of Mechanical Engineerg, Siddaganga Institute of Technology, Tumakuru, IN
6 Department of Mechanical Engineering, Jyothy Institute of Technology, Bengaluru-560082, Karnataka, IN

Abstract

MMCs exhibit increased modulus, strength, and fatigue strength. In MMCs, reinforcements can either be discontinuous or continuous or a combination of both. Owing to lower aspect ratio, and random orientation of the reinforcements, discontinuously reinforced composites exhibit comparatively higher isotropic properties than composites that are continuously reinforced. In the current research an attempt has been made to carry out experiments on Al-7Si and Fly ash and Graphite hybrid composites which were fabricated in steps of 3 wt.% of Flyash with 3 wt.% of Graphite and 3 wt.% of Flyash with 5 wt.% of Graphite for 25mm and 75mm diameter dies. Microstructural characterization of the specimens prepared following SEM, XRD, and EDS. Mechanical properties like hardness, yield strength, and ultimate tensile strength were evaluated as per ASTM standards. The composites prepared in 25 mm cast iron die were exhibited superior mechanical properties as compared to the composites prepared in the 75 mm diameter cast iron die. Further, with the addition of fly ash and graphite particles mechanical properties of Al-7Si alloy were improved.

Keywords

Al-7Si Alloy, Graphite, Fly Ash, Microstructure, Tensile Strength, Hardness.

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Gopal Krishna U B ¹, Vasudeva B ², Virupaxi Auradi ², Madeva Nagaral ³

Affiliations
1 Research Scholar, Dept. of ME, SIT, Tumkur and Assistant Professor, Dept. of ME, AIET, Moodbidri, Karnataka., IN
2 Associate Professor, Dept. of ME, SIT, Tumkur, Karnataka., IN
3 Deputy Manager, HAL, Bengaluru, Karnataka, IN

Abstract

Aluminium matrix composites (AMCs) have found uses in aircraft, rocket engineering, vehicle engineering, energy sector, infrastructure areas, marine and military applications, sports and recreation utilization because of its enormous mechanical strengths and sensible wear resistance features. The experimental results of 7075Al-WC-Co composites’ mechanical and tribological properties are provided in this article. The matrix is Al7075 and the reinforcement is planetary ball milled WC-Co in cermet form with particulates size range from 30-40 μm. Liquid metallurgy route was followed to develop 7075Al composites reinforced with 6, 9 and 12 wt.% of WC-Co. The tests were carried out on 7075Al and composites in accordance with ASTM specifications. According to the experimental results, the hardness of 7075Al-WC-Co composites is discovered to be raised by increasing the percentage volume of cermet phase. Wear attributes of the WC-Co containing composite were superior in terms of wear resistance. The manufactured composites were characterized using SEM and EDAX. Worn surface of the composite samples are studied before and after wear test.

Keywords

Aluminium, Metal Matrix Composites, Tungsten Carbide, Wear and Hardness.

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