| 1. |
- Chaudhary, Bhavesh, et al.
(författare)
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Friction stir powder additive manufacturing of Al 6061/FeCoNi and Al 6061/Ni metal matrix composites : Reinforcement distribution, microstructure, residual stresses, and mechanical properties
- 2023
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Ingår i: Journal of Materials Processing Technology. - : Elsevier. - 0924-0136 .- 1873-4774. ; 319
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Tidskriftsartikel (refereegranskat)abstract
- Fusion based additive manufacturing (FBAM) of second, sixth, and seventh series Al alloys and their metal matrix composites (MMC) is difficult due to their higher thermal conductivity and solidification related problems namely porosity, cracks, thermal distortion, and formation of undesired phases. This paper presents friction stir powder additive manufacturing (FSPAM) process as a promising alternative to overcome these problems in producing multi-layer depositions of Al 6061 based MMCs namely Al 6061/6wt%FeCoNi and Al 6061/6wt%Ni. Their microstructure, distribution and elemental mapping of reinforcement particles, phase analysis, residual stresses of the MMCs and their correlation with microhardness, tensile strength, and fretting wear characteristics are investigated. Material accumulation on their advancing side was minimized by changing tool rotation direction in consecutive layers which produced smoother surfaces on both sides of their deposition. FSPAM made multi-layer depositions of Al 6061/FeCoNi and Al 6061/Ni MMCs have uniform distribution of reinforcement particles, good bonding between layers without cracks and defects, refined and equiaxed grains facilitated by dynamic recrystallization and pinning effect of reinforcement particles, compressive residual stresses of 39 and 48 MPa, no formation of deleterious intermetallic compounds due to absence of melting of matrix and reinforcement, and bowl-shaped substrate-deposition interface. Microhardness and ultimate tensile strength of the MMCs improved by 11.3% and 22.3%, and 30.5% and 31.5% respectively than Al 6061 alloy depositions, their wear resistance enhanced significantly, but % elongation reduced. This study proves FSPAM to be a potential alternative to FBAM processes for better quality multi-layer deposition of Al alloy-based MMCs.
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| 2. |
- Patel, Mahesh, et al.
(författare)
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Enhancement of tensile and fatigue properties of hybrid aluminium matrix composite via multipass friction stir processing
- 2022
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Ingår i: Journal of materials research and technology. - : Elsevier. - 2238-7854. ; 21, s. 4811-4823
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Tidskriftsartikel (refereegranskat)abstract
- In present work, friction stir processing (FSP) has been used to fabricate hybrid aluminium matrix composite (HAMC) using a mixture of 6% ZrO2 and 6% Ni as reinforcement particles. Four different passes (1, 2, 4, and 6) were used to study the influence of multipass FSP on tensile properties, residual stresses, and fatigue performance of HAMCs. Six pass FSP led to significantly improved tensile properties due to more uniform distribution of reinforced particles and refined grains, and enhanced compressive residual stresses to-106 +/- 6.8 MPa compared to-9 +/- 1.8 MPa in base material. The increment in fatigue life of HAMCs is 31% (two passes), 61% (four passes), and 69% (six passes) as compared to the base material (4.08 x 105 cycles) for the lowest maximum applied stress of 100 MPa. The fatigue fracture characteristics of HAMCs with more than one FSP pass were found to be ductile-brittle mixed mode. The study concluded better fatigue life of (c) 2022 The Author(s). Published by Elsevier B.V.
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| 3. |
- Chaudhary, Bhavesh, et al.
(författare)
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Exploring temperature-controlled friction stir powder additive manufacturing process for multi-layer deposition of aluminum alloys
- 2022
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Ingår i: Journal of Materials Research and Technology - JMR&T. - : Elsevier. - 2238-7854. ; 20, s. 260-268
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents preliminary study on multi-layer deposition of aerospace grade Al 6061 alloy by novel friction stir powder additive manufacturing process. Minimum temperature of deposition was in-situ maintained using close loop temperature-controlled system for minimizing thermal gradient in the build direction. Maximum temperature during the deposition was monitored in-situ using pyrometer and thermal imaging camera. Use of a tool with circumferential and radial grooves and continuous external heating facilitated smooth three-layer deposition of Al 6061 alloy with 60% deposition efficiency and 417 degrees C as maximum deposition temperature. Larger value of temperature at deposition zone improved material flowability and deposition quality. Microstructure of multi-layer deposition found to consist of fine sub-grains. Element analysis showed uniform distribution of major alloying elements in it. Phase analysis revealed Al along with Mg2Si hardening precipitates. Tensile strength and microhardness were close to the commercially available wrought AA6061-T4 alloy. It showed ductility with 16% elongation. The presented process is a viable alternative to fusion-based additive manufacturing processes for multi-layer depositions of aerospace grade and other lightweight alloys which are difficult-to-additively-manufacture.
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| 4. |
- Harwani, Deepika, et al.
(författare)
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High temperature tensile deformation in single-pass friction stirred AZ31 alloy
- 2023
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Ingår i: International Journal of Lightweight Materials and Manufacture. - : KeAi Publishing Communications Ltd.. - 2589-7225 .- 2588-8404. ; 6:1, s. 140-148
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Tidskriftsartikel (refereegranskat)abstract
- The present study has expounded the effect of high temperatures on the tensile deformation of AZ31 magnesium alloy processed through a single-pass of friction stir processing (FSP). The major operation parameters, namely rotation speed and traverse speed of the FSP tool, were varied which led to extensive dynamic recrystallization (DRX) in the stir zone (SZ) engendering maximum grain refinement of about 63% as compared to the base metal. The lowest average grain size ∼ 5.66 μm was attained after a single FSP pass. Optical microscopy (OM) was followed by the uniaxial tensile tests at three different temperatures of 350, 400 and 450 ºC at a constant strain rate of 1.3 × 10−3/s. As the deformation temperature was raised, the flow stress reduced and led to appreciable increments in the processed material’s tensile elongations. The maximal elongation to fracture of 160% was observed in the friction stir processed (FSPed) sample possessing the finest grains.
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| 5. |
- Harwani, Deepika, et al.
(författare)
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Investigation of superplastic behaviour in double-pass friction stir processed Mg-Al-Zn alloy
- 2023
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Ingår i: International Journal of Lightweight Materials and Manufacture. - : Elsevier. - 2589-7225 .- 2588-8404. ; 6:3, s. 405-415
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Tidskriftsartikel (refereegranskat)abstract
- Double-pass friction stir processing (FSP) engendered intense plastic deformation in Mg–3Al–1Zn alloy with variation in the most influential process parameters, namely tool rotation speed and tool traverse speed. The effect of change in the FSP processing route on the resulting grain size was also analysed. Uniformly distributed fine equiaxed grains (average grain size ∼ 6.15 μm) were acquired in the stir-zone (SZ) due to extensive dynamic recrystallization (DRX). Attainment of large grain refinement encouraged for further investigation of the alloy's superplastic behaviour at elevated temperatures. Microstructural examination was followed by uniaxial tensile tests that were carried out at three distinct temperatures of 350, 400 and 450 °C at the constant strain rate of 1.3 × 10−3 s−1. With the rising deformation temperature, reduction in the flow stress led to significant increase in the tensile elongations of all the processed specimens. Micro-grain superplasticity (elongation >200% under tension) was observed at the highest deformation temperature for the friction stirred specimen with the finest grains.
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| 6. |
- Mehta, Kamlesh, et al.
(författare)
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Experimental Investigations of a Minichannel Heat Sink for Electronic Applications
- 2022
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Ingår i: Iranian Journal of Science and Technology - Transactions of Mechanical Engineering. - : Institute for Ionics. - 2228-6187 .- 2364-1835.
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Tidskriftsartikel (refereegranskat)abstract
- In the current study, a new configuration of minichannels is proposed to improve the thermal performance of conventional plate-fin aluminum heat sink used for the thermal management of the electronic components. The case under consideration to implement the current idea is an aluminum heat sink equipped with rectangular square minichannels. Hence, an enhanced model is investigated, and the obtained results are evaluated as compared with the conventional plate-fin aluminum heat sink. A minichannel heat sink (MC-HS) that has 18 parallel minichannels was developed on the aluminum plate and charged with acetone. The experimental results demonstrated that the proposed MC-HS startup was successfully under a heat load ranging from 10 to 40 W in the vertical orientation. From the investigations, a MC-HS is found to be more effective for the thermal management of the electronic components than the conventional method. The thermal resistance of the MC-HS is 20–31% lower in comparison with the conventional plate-fin aluminum heat sink. It is shown that the MC-HS not only surpasses the conventional solution but also provides greater thermal management of the electronic components.
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| 7. |
- Srivastava, Manu, et al.
(författare)
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A review of various materials for additive manufacturing : Recent trends and processing issues
- 2022
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Ingår i: Journal of materials research and technology. - : Elsevier. - 2238-7854. ; 21, s. 2612-2641
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Tidskriftsartikel (refereegranskat)abstract
- Tremendous growth has been witnessed in the field of additive manufacturing (AM) technology over the last few decades. It offers a plethora of applications and is already being utilized in almost every sphere of life. Owing to inherent differences between each AM technique, newer fields of research consistently emerge and demand attention. Also, the innovative applications of AM open up newer challenges and thus avenues for focused attention. One such avenue is AM materials. Raw material plays an important role in determining the properties of fabricated part. The type and form of raw material largely depend on the type of AM fabricators. There is a restriction on material compatibility with most of the established AM techniques. This review aims to provide an overview of various aspects of AM materials highlighting the progress made especially over the past two decades.
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| 8. |
- Vora, Jay, et al.
(författare)
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Experimental investigations on mechanical properties of multi-layered structure fabricated by GMAW-based WAAM of SS316L
- 2022
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Ingår i: Journal of Materials and Research Technology -JMR&T. - : Elsevier. - 2238-7854. ; 20, s. 2748-2757
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, the Gas metal arc welding (GMAW) based Wire-arc additive manufacturing (WAAM) process was used to fabricate a multi-layered structure at opti-mized process parameters on SS316L using metal wire of SS316L. The multi-layered structure’s microstructure, macrostructure, and mechanical properties (tensile test, impact test, microhardness, and fractography) were examined at three locations at the top, middle, and bottom sides of the structure. Macrostructure at different zones has confirmed an appropriate bonding between the two layers, complete fusion without oxidation, and free from defects and unwanted geometries. Microstructure results have observed a colony of columnar dendrites in the bottom zone, coarser grains with vertical growth along with the residual ferrite in the middle zone, and vertical dendritic structure with residual ferrite in skeletal shape in the top zone. Results of all tensile properties for top, middle and bottom zone developed by the WAAM process fall in the range values of wrought SS 316 L. The microhardness values were shown a consistent behavior across the built structure in all three zones. The obtained average value for the impact test has shown better strength than commercially used wrought SS 316 L. The results of fractured tensile and fracture impact test specimens revealed many dimples, which suggests a good ductility of the as -built structure. Thus, the obtained results have shown that the built structure using the GMAW-based WAAM process matches the standards for industrial applications.
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