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    A holistic research based on RSM and ANN for improving drilling outcomes in Al-Si-Cu-Mg (C355) alloy
    (Elsevier, 2025) Bayraktar, Senol; Alparslan, Cem; Salihoglu, Nurten; Sarikaya, Murat
    The unique properties of Al-Si-based alloys make them suitable for components that demand structural integrity and wear resistance. This study was conducted to investigate the microstructure, mechanical, and drilling properties of a commercial alloy belonging to the Al-Si casting alloy group and containing approximately 4.5-5.5% Si (Al-5Si-1Cu-Mg). Drilling experiments were conducted with an 8 mm uncoated HSS (High-Speed Steel) drill across a range of cutting speeds (V) and feed rates (f) while maintaining a consistent depth of cut (DoC) parameters. Microstructural analysis using optical microscopy and SEM identified key phases within the alloy, including alpha-Al, eutectic Si, beta-Fe (beta-Al5FeSi), and pi-Fe (pi-Al8Mg3FeSi6) inter-metallics. Statistical analyses of the effects of V and f on thrust force (Fz), surface roughness (Ra), and torque (Mz) were performed using Response Surface Methodology (RSM), Artificial Neural Networks (ANN), and Analysis of Variance (ANOVA). The ANOVA results highlighted the significance of both V and f on the measured outputs, with optimal performance observed at a V of 125 m/min and f of 0.05 mm/rev (confidence level: 95%, P < 0.05). Additionally, predictive models based on RSM and ANN were developed for Fz, Ra, and Mz.
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    Öğe
    The impact of heat treatment process on the drilling characteristics of Al-5Si-1Cu-Mg alloy produced by sand casting
    (Elsevier, 2024) Bayraktar, Senol; Alparslan, Cem; Salihoglu, Nurten; Sarikaya, Murat
    Aluminum-Silicon (Al-Si) based materials are commonly preferred in engineering studies requiring high mechanical performance as an alternative to steel materials. These alloys are especially preferred in the automotive industry, aerospace components and heavy machinery parts. In post-casting processes, machining operations are of great importance for high geometric precision, surface quality and longer fatigue life in mechanical environments. In this research, the microstructural, mechanical and machining characteristics of the Al-5Si-1Cu-Mg material produced by sand casting method in both as-cast (AC) and heat-treated (HTed) (Solid solution, quenching and aging-SQA) states were experimentally investigated. Microstructural examinations were carried out with optical microscope and SEM images. Mechanical properties were determined by tensile and hardness tests. Then, drilling experiments were performed in the CNC vertical machining center with 8 mm diameter uncoated HSS (High Speed Steel) cutting tools at constant cutting conditions (i.e., cutting speed-V: 125 m/min, feed rate-f: 0.05 mm/rev and depth of cut-DoC: 15 mm). In microstructural investigations, it was determined that the microstructure of the Al-5Si-1Cu-Mg material in AC state consists of alpha-Al, eutectic Si, beta-Fe (beta-Al5FeSi) and it-Fe (it-Al8Mg3FeSi6) intermetallics. After the SQA, the existing phases generally exhibited a spherical structure, and it was seen that the beta phase in the microstructure transformed into the circle minus (Al7FeCu2) phase. SQA improved the hardness, yield and tensile durability of the material, whereas decreasing the elongation to fracture. SQA process improved the machining characteristics of the material by decreasing thrust force, moment, surface roughness and built-up edge (BUE) formation. The machined subsurface structure of HTed alloy under constant cutting conditions was determined to be more stable and smooth and the machined surface microhardness of HTed alloy was higher compared to as-cast alloy due to the effect of solid precipitation hardening. In addition, shorter and more broken chips occurred in the machining of HTed alloys due to the effect of low elongation to fracture.