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    Numerical and experimental investigations of built orientation dependent Johnson-Cook model for selective laser melting manufactured AlSi10Mg
    (Elsevier, 2021) Akturk, Murat; Boy, Mehmet; Gupta, Munish Kumar; Waqar, Saad; Krolczyk, Grzegorz M.; Korkmaz, Mehmet Erdi
    Powder bed fusion based additive manufacturing techniques involve melting or sintering of powder particles via laser beams to join them in order to attain desired shapes. This study aims to provide basis for material constitutive parameters of widely used aluminum alloy AlSi10Mg alloy. Initially, tensile samples of AlSi10Mg alloy samples were manufactured by using SLM technology. Afterwards, through quasi-static and high temperature tensile tests, an attempt has been made to determine the Johnson-Cook material model of AlSi10Mg. in order to conduct quasi-static tensile tests, strain rates of 10(-3) s(-1), 10(-2) s(-1) and 5 x 10(-2) s(-1) were considered and tests were conducted at ambient temperature. Whereas, for high temperature tensile tests 24,150, 300 degrees C temperature values were considered at the reference strain rate value of 10(-3) s(-1). The numerically simulated tensile results achieved by using the established Johnson-Cook model were then compared with experimental results. It was observed that the maximum error between the test and simulation results was around of 7.5%. The error percentage is well within the acceptable, thus proving the accuracy of the established material model. (c) 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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    A review on microstructure, mechanical behavior and post processing of additively manufactured Ni-based superalloys
    (Emerald Group Publishing Ltd, 2024) Kuntoglu, Mustafa; Salur, Emin; Gupta, Munish Kumar; Waqar, Saad; Szczotkarz, Natalia; Vashishtha, Govind; Korkmaz, Mehmet Erdi
    PurposeThe nickel-based alloys Inconel 625 and Inconel 718 stand out due to their high strength and corrosion resistance in important industries like aerospace, aviation and automotive. Even though they are widely used, current techniques of producing materials that are difficult to cut pose several problems from a financial, ecological and even health perspective. To handle these problems and acquire improved mechanical and structural qualities, laser powder bed fusion (LPBF) has been widely used as one of the most essential additive manufacturing techniques. The purpose of this article is to focus on the state of the art on LPBF parts of Inconel 625 and Inconel 718 for microstructure, mechanical behavior and postprocessing.Design/methodology/approachThe mechanical behavior of LPBF-fabricated Inconel is described, including hardness, surface morphology and wear, as well as the influence of fabrication orientation on surface quality, biocompatibility and resultant mechanical properties, particularly tensile strength, fatigue performance and tribological behaviors.FindingsThe postprocessing techniques such as thermal treatments, polishing techniques for surface enhancement, mechanical and laser-induced peening and physical operations are summarized.Originality/valueThe highlighted topic presents the critical aspects of the advantages and challenges of the LPBF parts produced by Inconel 718 and 625, which can be a guideline for manufacturers and academia in practical applications.
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    A short review on thermal treatments of Titanium & Nickel based alloys processed by selective laser melting
    (Elsevier, 2022) Korkmaz, Mehmet Erdi; Gupta, Munish Kumar; Waqar, Saad; Kuntoglu, Mustafa; Krolczyk, Grzegorz M.; Maruda, Radoslaw W.; Pimenov, Danil Yu.
    Selective laser melting (SLM) has been considered as a well-researched technology used to produce near net shape metallic components with superior mechanical and physiochemical characteristics. Recently SLM has recently been used for the production of components made by high-performance alloys such as Titanium and Nickel. However, the microstructural and physical anisotropy along with the defects have negative impact on the performance and behavior of SLM-produced alloys. Therefore, to improve the material characteristics, extra attention must be paid to the source(s), identification, and removal of these deviations. Thermal heat treatments are often considered as an effective approach to deal with aforementioned issues. stress-relieving, quenching/hardening, annealing/ recrystallization, and thermo-mechanical heat treatments are among prominent procedures adopted for the post processing of SLM fabricated metallic components and hence considered in this article. Since these procedures have substantial impact on the microstructure and mechanical behavior therefore an assessment of their influence and resulting changes is significantly important. Therefore, this short review provides the said knowledge on thermal treatments used to improve the SLM fabricated titanium and nickel based alloys. This review can significantly help in designing and selecting appropriate post processing thermal treatments keeping in mind the expected outcome. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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    A technical overview of metallic parts in hybrid additive manufacturing industry
    (Elsevier, 2022) Korkmaz, Mehmet Erdi; Waqar, Saad; Garcia-Collado, A.; Gupta, Munish Kumar; Krolczyk, Grzegorz M.
    Additive manufacturing technologies have emerged as the promising alternatives of conventional manufacturing techniques. Conventional manufacturing techniques involves cutting and removal of material by mechanical procedures to achieve final product. Whereas, discrete chunks of material in any form are combined point by point and layer by layer for the fabrication of final product in additive manufacturing processes. Numerous advantages and inefficiencies of these manufacturing techniques are reflected in factors such as the design, fabrication, material properties and working condition etc. Therefore, development of a production technology by combining the benefits of both conventional and additive techniques is significantly important. Hybrid Manufacturing jointly apply additive and conventional production methods to attain final products. Hence, this short overview covers the operation aspects of both additive and subtractive manufacturing of metallic materials. (c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).