 Subjects -> METALLURGY (Total: 59 journals)
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- Innovative processing routes in manufacturing of metal matrix composite
materials
Authors: Jovana Ruzic, Marko Simić, Nikolay Stoimenov, Dušan Božić, Jelena Stašić
Pages: 1 - 13
Abstract: Metal matrix composites (MMCs) belong to a group of modern materials owing to their excellent technological, mechanical, and physical properties such as excellent wear and corrosion resistance, high electrical and thermal conductivity, improved strength and hardness. Final properties of MMCs are affected equally by all steps of its manufacturing process. It is shown that by using adequate process parameters to obtain starting materials (reaching the specific size, shape, and reactivity) the control of volume fraction and distribution of reinforcements within the matrix can be achieved. For this purpose, mechanical alloying has been appointed as a good approach. MMCs can be produced using powder metallurgy, ingot metallurgy, and additive manufacturing techniques. Combining high-energy ball milling with these techniques enables the design of an innovative processing route for MMCs manufacturing. Mechanochemical process (achieved using high-energy ball milling) was employed in three manufacturing procedures: hot pressing, compocasting, and laser melting/sintering for obtaining of the suitable powder. These production routes for MMCs manufacturing were the subject of this work. The aim of MMCs design is to establish an optimal combination of production techniques merged into the cost-effective fabrication route for obtaining MMCs with required properties.
PubDate: 2021-03-30
DOI: 10.30544/629
Issue No: Vol. 27, No. 1 (2021)
- Solid particle erosion resistance of Al alloy and Al alloy-fly ash
composite subjected to equal-channel angular pressing
Authors: Merima Muslić, Vera Rede, Vesna Maksimović
Pages: 15 - 26
Abstract: This paper describes the influence of deformation by equal-channel angular pressing (ECAP) on the solid particle erosion resistance of the AlSi7Mg0.3 alloy and AlSi7Mg0.3 based composite material reinforced with the addition of 4 % of fly ash (FA) particles. Both, alloy and composite samples were produced using the compo-casting method. The samples have been subjected to ECAP in multiple passes with the rotation of samples around the vertical axis for the angle of 90° after each pass. Particles of silicon carbide (SiC) have been used as erodent while their impact angle was varied (30° and 90°). Observed samples of AlSi7Mg0.3 alloy generally showed higher wear resistance at 90° angle where material fatigue predominates, than at a 30° angle where abrasion-related phenomena predominate. On the other hand, AlSi7Mg0.3 based composite material exhibited erosion wear at 30° angle less than at 90° angle after one ECAP pass. Evaluation of the erosion resistance has been made based on mass and volume loss. After two passes of ECAP, the matrix structure of the AlSi7Mg0.3 based composite material, as well as that of the AlSi7Mg0.3 alloy was improved from the aspect of erosion resistance.
PubDate: 2021-03-23
DOI: 10.30544/624
Issue No: Vol. 27, No. 1 (2021)
- Effect of addition of SiC particles on the Microstructure and Hardness of
Al-SiC composite
Authors: Hareesha G, N Chikkanna, Saleemsab Doddamani, Anilkumar S Kallimani
Pages: 49 - 56
Abstract: This work aims to investigate the effect of the addition of silicon carbide particles on the microstructure and the hardness of the Al-SiC metal matrix composites. The said composite is prepared using the stir casting technique for different weight percentages of the SiC particles. The higher composition of the reinforcement causes the clustering of the particles in the matrix. Thus, research has to be carried out on the aluminum-silicon carbide composites with the reinforcement 3wt%, 6wt%, 9wt%, and 12wt% of SiC particles to obtain the optimized composition. In order to study the microstructure and the reinforcement distribution in the matrix, a scanning electron microscope is utilized. The hardness testing has been carried out using the Vickers’ indentation technique for the as-cast and age hardening conditions. From the microstructural study, it is observed that the microstructure of the said composite exhibits the uniform distribution of the reinforcement. The EDX results show the presence of the reinforcing elements in the Al-SiC composite. From the results obtained from the hardness testing, it is observed that the presence of the carbide element in the composite increases the hardness of the Al-SiC particulate composites.
PubDate: 2021-03-22
DOI: 10.30544/590
Issue No: Vol. 27, No. 1 (2021)
- Friction and wear reduction by graphene nano platelets for hybrid nano
Aluminium matrix composite under dry sliding conditions
Authors: Pranav Dev SRIVYAS, M.S. CHAROO
Pages: 27 - 47
Abstract: Friction losses and wear losses are the main failure reasons in the internal combustion (IC) engine components i.e., cylinder liner and piston. So, it demands lightweight self-lubricating low friction and wear-resistant materials to increase the efficiency and reduce the emission issue of the IC engine. In this concern, tribological tests are performed on self-lubricating aluminium composites samples reinforced with 6 wt.% of γ-Al2O3 and Graphene Nano Platelets (GNP) with varying concentration (0.5 wt.% - 5 wt.%), using ball-on-disc tribo-configuration under dry sliding conditions. The scope of this study is to investigate the anti-friction and anti-wear properties of GNP as reinforcement in the hybrid nanocomposite. The hybrid nanocomposite samples are fabricated using Spark Plasma Sintering (SPS) fabrication route. From the results, it is reported that friction and wear reduction percentage is 37.43 % and 51.64 %, respectively for the hybrid nanocomposite with 5 wt. % GNP. It is attributed to the inclusion of GNP, which reduces the Coefficient of Friction (COF) and improves wear resistance of the composite significantly.
PubDate: 2020-11-19
DOI: 10.30544/536
Issue No: Vol. 27, No. 1 (2020)
- Microstructural and mechanical behavior of Al 6061/SiC-Al2O3 composites
processed through friction stir processing
Authors: Mohana Rao Chanamallu, K. Meera Saheb
Pages: 57 - 73
Abstract: Metal Matrix Composite (MMC) reinforced in friction stir processing (FSP) has increased insights that can affectively attain the desired mechanical properties for the manufactured samples. The favorable conditions of carbides are considered for reinforcing the SiC particles into the Aluminum 6061. The methodology of fabricating Aluminum 6061 comprises of three materials, Al 6061-SiC-Al2O3. The experimental evaluation of the composite Aluminum 6061-SiC-Al2O3 includes the influence of process parameters on microhardness, tensile strength, and microstructure. As a result of the reinforcement of nanoparticles processed in FSP, the properties of composite material increased satisfactorily. The sample S3 observed to be having a maximum tensile strength of 185 MPa. The larger, the better condition is adopted to analyze the tensile strength of the fabricated samples. The optimum condition for maximum tensile strength was found at 900 RPM, 15 mm/min, and composition 3. The hardness profiles at different zones of friction stir processing (FSP), viz., Heat Affected Zone (HAZ), Thermo Mechanical Affected Zone (TMAZ), Nugget Zone (NZ) were examined. The characterization techniques deployed were optical microscope (OM), and scanning electron microscope (SEM) studies for microstructural behavior. The result shows that the reinforcements were tightly embedded into the base material surface. The spherical grains are formed in the reinforcement region.
PubDate: 2020-08-17
DOI: 10.30544/495
Issue No: Vol. 27, No. 1 (2020)
- Improved corrosion resistance, mechanical and wear behaviors of
particulate composite coating of steel pipeline for marine environment
Authors: Suleiman Idawu Yakubu, Obayi C. S; Dr., Mu'azu K. None, A. T. Mohammed
Pages: 75 - 87
Abstract: The use of agricultural wastes, which are cost-effective and environmental-friendly materials as composites coating, is growing fast in various engineering fields. This research investigates the possibility of improving corrosion resistance, mechanical, and wear behaviors of particulate composite coating of steel pipeline with zinc alloys reinforced with groundnut shell ash (GSA) for the marine environment. Different weight percentages of 5, 10, 15, 20, and 25 wt.% GSA of particle size 75 μm were used for the coatings. The groundnut shell ash was characterized by X-ray fluorescent (XRF). The morphology of the steel pipeline before and after coatings was studied using scanning electron microscope/Energy Dispersive Spectroscopy (SEM/EDS). The XRF results revealed that calcium oxides (CaO), silica (SiO2), alumina (Al2O3), and iron oxide (Fe2O3) being the major oxides present. The results showed that average coating thickness and hardness value were 45.50, 98.50, 99.67 μm, and 80.45, 108.60, 118.60 HBV for Zn-10ZnO/0, 20, and 25 wt. % GSA respectively. Their corresponding current corrosion (icorr) were 38.52, 10.56, and 2.98 mA/cm2. The morphologies revealed that reinforcement with GSA protected the surface of the system analyzed. The corrosion rate of the steel pipeline of 38.52 mA/cm2 values decreased to 10.56 mA/cm2 and 1.98 mA/cm2 for 0, 20, and 25 wt. % GSA with the protection efficiency of 72.59% and 81.25%, respectively. The wear rate improvement between 0-25 wt. % GSA was 49.75%. The work established Zn-10ZnO/GSA composite coating on steel pipeline can improve the corrosion resistance, hardness, and wear rate of the studied steel pipeline coated.
PubDate: 2020-10-14
DOI: 10.30544/510
Issue No: Vol. 27, No. 1 (2020)
- Development and characterization of hybrid coconut/glass fibers reinforced
low density polyethylene composites for bumper application
Authors: Akinlabi O. David, Ibeh Stanley Chukwuemeka, Enegide E. Osther, Garba N. Salihu
Pages: 89 - 104
Abstract: The EU's End of Life Vehicles (ELV) regulations are forcing car manufacturers to consider the environmental impact of their production and possibly shift from the use of synthetic materials to the use of agro-based materials. However, poor mechanical properties and certain manufacturing limitations currently limit the use of agro-based materials to non-structural and semi-structural automotive components. This research is focused on a composite of hybrid coconut/glass fiber as reinforcement in recycled low density polyethylene matrix alone to enhance the desired mechanical properties for car bumper as automotive structural components. X-ray fluorescence analysis conducted on coconut fiber showed the presence of silica and alumina materials make coconut fibre a choice one. Morphology analysis was performed using scanning electron microscopy (SEM), which reveals that there are small discontinuities and reasonably uniform distribution of the reinforcement fibers and the reinforced low density polyethylene (RLDPE) binder resulting to better mechanical properties. Physic-chemical properties that directly affect developed composite such as variation of Density, Water Absorption, Tensile Strength, Bending strength, Modulus of rupture, Impact Strength and Hardness Values were investigated for both unhybridized and hybridized developed composite. The study shows the successful development of composites of coconut fiber (CF) hybridized with glass fiber (GF) and reinforced low density polyethylene (RLDPE) binder using a simple molding technique. Hybridized samples (CF-GF/RLDPE) showed higher strength when compared to un-hybridized (CF/RLDPE) composites. Better microstructural bonding exists with 25% and 30% wt CF-GF composite resulting in good mechanical properties for the hybridized composites. The grades of composites obtained in the course of this study are applicable in the production of low strength car bumpers.
PubDate: 2020-08-03
DOI: 10.30544/453
Issue No: Vol. 27, No. 1 (2020)
- Chemical durability of sintered glass-composite prepared from glass cullet
and waste foundry sand
Authors: Veljko Savić, Vladimir Topalović, Srđan Matijašević, Jelena Nikolić, Snežana Grujić, Snežana Zildžović, Aleksandra Radulović
Pages: 105 - 115
Abstract: In this study, the glass-composite was prepared using glass cullet and waste foundry sand as raw materials. The powder technology route was employed. The mixtures containing 10-50 wt% of the sand were sintered at T = 750 °C for t =1h. XRD and DTA analyses were performed. The chemical durability of the resulting glass-composite was determined by leaching test in HCl, H2SO4, NaOH and distilled water at T = 95 °C for t =1h. It was shown that the sintering process carried out without the crystallization of the glass matrix. The lowest chemical durability was determined in alkali solution of glass-composite.
PubDate: 2020-07-28
DOI: 10.30544/477
Issue No: Vol. 27, No. 1 (2020)
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