Browsing by Author "Trembach, Bohdan O."

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    Hybrid Optimization of Hardfacing Conditions and the Content of Exothermic Additions in the Core Filler During the Flux-Cored Arc Welding Process
    (MDPI, 2026) Trembach, Bohdan O.; Dmitriiev, Oleh; Kulahin, Kostiantyn; Balenko, Oleksii; Maliuha, Volodymyr; Neduzha, Larysa O.
    ENG: This study introduces a hybrid optimization method to enhance the melting characteristics and weld bead morphology of flux-cored wire hardfacing with exothermic addition into the core filler. The Taguchi Design of Experiments (L9 orthogonal array) was used to analyze the effects of key conditions on multiple melting characteristics. The hybrid Taguchi-GRA-PCA effectively identified the best parameter combination, resulting in a significant improvement in overall melting performance. The impact of welding modes on weld bead parameters and melting characteristics was examined. It was determined that the optimal amount of the exothermic addition CuO-Al introduced into the flux-cored wire filler should be a medium level (EA = 28 wt.%). Results showed that wire feed speed WFS and EA had the greatest effect on MOR and DR, while EA and CTWD mainly influenced SF and De. It has been determined that the content of the exothermic additive has a significant impact on the melting process of filler materials, affecting the melting characteristics and weld bead morphology. It has been found that the melting characteristics of deposition rate and spattering factor can be used to optimize welding modes and characterize most output parameters of the welding/surfacing process.
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    Optimisation of Elemental Transfer Efficiency in Fe-C-Cr-Ti-Cu Hardfacing by Self-Shielded Flux-Cored Wire: A Synergistic Taguchi–ANOVA–FD–PCA–GRA Approach
    (MDPI, 2026) Trembach, Bohdan O.; Krbat'a, Michal; Haibadulov, Borys; Iokhov, Oleksandr; Tsebriuk, Ivan; Pomohaiev, Ihor; Korobkov, Yurii; Neduzha, Larysa O.
    ENG: The objective of this article is to optimise the deposition modes and the content of exothermic additions (EAs) in the core filler in Fe-C-Cr-Ti with Cu additions hardfacing. To achieve this, JMatPro Release 7.0, Sente Software Ltd., 2016 material characterisation software was used to simulate and calculate the equilibrium phase structure and composition of the Fe-C-Cr-Ti-Cu alloy during the welding thermal cycle. A synergistic approach combining the Taguchi–Analysis of Variance (ANOVA)–Factorial design (FD) method with the standard hybrid Taguchi–ANOVA–Principal Component Analysis (PCA)–Grey Relational Analysis (GRA) is used and justified to optimise factors and develop mathematical models for parameters in the L9 orthogonal experimental design. The study examines how the transfers of deoxidisers depend on the content of exothermic additions in the cored wire filler (EA) and the contact tip-to-work distance (CTWD), while the behaviour of carbide formers is influenced by wire feed speed (WFS) and present arc voltage at the power source (Uset). The research specifically investigates the Fe-C-Cr-Ti-Cu system and the role of copper in stabilising austenite. Findings show that high Cu concentrations (7 wt.%) enhance hardenability by 13%, effectively suppressing pearlite transformation and expanding the bainite region. The desired chemical composition of the deposited metal is determined by the distribution of selected factors, as measured by the transfer coefficients of each element.