Journal Articles
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Item Investigating Mechanical and Corrosion Behavior of Plain and Reinforced AA1050 Sheets Fabricated by Friction Stir Processing(Springer, 2020) Vinayak, V.R.; Bajakke, P.A.; Jambagi, S.C.; Chavana, C.; Deshpande, A.S.The present investigations help in improving the bendability and corrosion resistance of AA1050 rolled sheets by selective friction stirring. The processing of AA1050 with a tapered square pin at a tool rotation speed of 1200 rpm yielded the highest strain of 0.345 at ultimate tensile strength compared with 0.054 in as-received material. The identified processing conditions produced an ultimate tensile strength of 89.23 MPa with a toughness of 34.451 × 106 J/m3 and a lower corrosion rate with Icorr of 0.324 × 10?6 A/cm2. Further, processing with a simple tapered circular pin resulted in maximum ultimate tensile strength of 102 MPa with a toughness of 33.990 × 106 J/m3. However, it came at the expense of least resistance to corrosion with Icorr of 4.813 × 10?6 A/cm2. Consequently, the addition of zinc oxide during friction stirring showed a remarkable improvement in corrosion resistance with Icorr of 0.094 × 10?6 A/cm2. Future studies are planned on these lines. © 2020, The Minerals, Metals & Materials Society.Item Unidirectional flipped multiple-pass friction stir process: an innovative step in the fabrication of in situ Al-Cu composites(Springer Science and Business Media Deutschland GmbH, 2024) Bajakke, P.A.; Vinayak, V.; Jambagi, S.C.; Bhajantri, V.; Deshpande, A.S.The in situ Al-Cu composites were manufactured by powder metallurgy with state-of-the-art microwave sintering tailed by friction stir process in two different ways: unidirectional overlapped two-pass and unidirectional flipped two-pass. Novelty is claimed in the flipped process. An attempt was made to investigate the addition of copper beyond the solubility limit and the critical composition of an Al-Cu alloy (4.6 wt.%). The overlapped process enforced higher temperature, cumulative strain, and strain rate. Since Al and Cu are high-stacking fault energy metals, both dynamic recrystallization and dynamic recovery occurred and resulted in grain refinement and higher fractions of Al2Cu. The self-hard and brittle nature of Cu and Al2Cu improved strength (Al-3wt.%Cu, 231.23 MPa), hardness (Al-6wt.%Cu, 82.5 HV), and deteriorated ductility (Al-7wt.%Cu, 5.2%). The formed Al2Cu at the interface were surrounded by Al particles and formed passive films Al2O3 and Cu2O enhanced corrosion resistance (Al-5wt.%Cu, 0.00717191 mpy). The process densely compacted the material, minimized porosity, decreased dislocation density, and increased strain aided in better electrical conductivity (Al-5wt.%Cu, 145.92%IACS). The flipped process circumvented excessive heating and embrittlement of the material thereby improving strength without loss of ductility (Al-7wt.%Cu, 235.85 MPa and 25.53%). Al-3wt.%Cu with minimum corrosion current (5.681 µA/cm2) exhibited maximum resistance to corrosion (0.169852 mpy). The highest electrical conductivity was noticed for (Al-5wt.%Cu, 104.17%IACS). © The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature 2024.Item Comparative analysis of flipped and overlapped microwave sintered plus friction stir processed in-situ Al-Cu composites(Springer Nature, 2024) Vinayak, V.R.; Bajakke, P.A.; Jambagi, S.C.; Bhajantri, V.; Deshpande, A.S.The in-situ Al-Cu composites were fabricated with Cu content more than the solubility limit (5.65%) and the critical composition of an Al-Cu alloy (4.6%). A powder metallurgy route with state-of-the-art microwave sintering and friction stir process with overlapped and flipped conditions was attempted. The overlapped friction stir resulted in a minimum area of nugget region, unidirectional material mixing, high heat input in successive passes, and brittleness in the material. This accounted for the material to exhibit high strength with low ductility. Whereas flipped friction stir leads to a maximum area of stir zone, bidirectional material mixing, and similar thermal cycles in individual passes and avoids excessive heating. This facilitated the material to possess maximum strength by retaining ductility. The newly developed in-situ Al-Cu composite material (with Cu wt% in ranges of 8–12) possesses equivalent strength, ductility, electrical conductivity, and rate of corrosion compared to copper. Notably, these attributes, combined with its cost-effectiveness, position this material as a promising alternative to copper conductors in electrical applications. From the present investigation, it is strongly recommended to choose a flipped friction stir for better properties. © Qatar University and Springer Nature Switzerland AG 2024.