Yazar "Hartomacioglu, Selim" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • [ X ]
    Öğe
    A review on aluminum alloys produced by wire arc additive manufacturing (WAAM): Applications, benefits, challenges and future trends
    (Elsevier, 2024) Sarikaya, Murat; Onler, Dilara Basil; Dagli, Salih; Hartomacioglu, Selim; Gunay, Mustafa; Krolczyk, Grzegorz M.
    Metal additive manufacturing is advancing with increasing momentum and attracting great attention. The Wire Arc Additive Manufacturing (WAAM) process, one of the metal additive manufacturing methods, involves melting a filler wire with an electric arc and depositing metal droplets layer by layer along the planned path. Aluminum alloys produced by the WAAM process have been in high demand in the industry, especially in the last decade. The WAAM process stands out as a suitable method for many industries due to its low investment cost, high deposition rates and the advantages of creating relatively complex parts. Key application areas of aluminum alloys produced using WAAM include aerospace, automotive, marine, and energy sectors, where lightweight structures, corrosion resistance, and high strength are critical. Much research has been done and innovative applications, including hybrid systems, have been developed to prevent defects such as residual stresses, cracks, porosity and delamination. This review article provides a comprehensive overview of the use of the WAAM process in aluminum alloys over the past decade. In the article, firstly, aluminum alloys, the WAAM technique and its types are introduced. In the following section, the methods used to improve mechanical properties and optimize the microstructure are examined in detail. In the next section, the difficulties encountered when using aluminum alloys in WAAM applications are discussed in detail. In the discussion section, current developments are evaluated, and in the last section, suggestions for future studies and inferences obtained from this study are presented. As a result, WAAM-CMT and hybrid systems were found to be effective in reducing defects such as porosity, distortion and residual stress. In addition, post-processing heat treatments and surface treatment methods are also crucial for improving mechanical properties. Finally, more research is needed in the areas of 7xxx series alloys, repair applications and environmental sustainability.
  • [ X ]
    Öğe
    Characterization, generative design, and fabrication of a carbon fiber-reinforced industrial robot gripper via additive manufacturing
    (Elsevier, 2024) Hartomacioglu, Selim; Kaya, Ersin; Eker, Beril; Dagli, Salih; Sarikaya, Murat
    Robot grippers are crucial components across various industrial applications, requiring special design and production for obtaining the optimal performance. Conventional plastic injection moulding techniques fall short in achieving the specificity needed for these grippers. To address this challenge, current paper focuses on developing a robot gripper using carbon fiber-reinforced polyamide with a next-generation composite filament and employing the innovative Generative Design technique. In the work, we began by characterizing and optimizing the composite material specifications. Then, the tensile strength and fracture mechanics of standard samples based on printing parameters, applying Taguchi experimental design for optimization were evaluated. Analysis of Variance (ANOVA) was used for factor analysis to fine-tune the process. Using the Generative Design technique, we determined optimal geometries, which were then fabricated through Fused Deposition Modeling (FDM). As a result, the optimization efforts led to significant improvements i.e., tensile strength increased from 103.2 to 116 MPa, and the elasticity modulus from 8386 to 8990 MPa. In practical industrial applications, we achieved a reduction in material weight from 14 to 4 g, lowered production costs from $5.16 to $1.50, and cut production time from 58 to 28 min. This study presents a validated method for developing industrial products with reduced material usage and costs, promoting sustainable production practices.
  • [ X ]
    Öğe
    Evaluation of shear strength and interlayer damage of short carbon fiber reinforced PA6 in FDM printing along critical ZX orientation
    (Elsevier, 2025) Hartomacioglu, Selim; Yayla, Pasa; Yazman, Sakir; Dagli, Salih; Sarikaya, Murat
    This study experimentally and numerically investigates the shear strength and interlayer damage mechanisms of short carbon fiber-reinforced Polyamide 6 (PA6-CF15) composites fabricated via Fused Deposition Modeling (FDM) along the critical ZX build orientation. Using a Taguchi experimental design, the effects of key processing parameters-nozzle temperature, layer thickness, number of outer walls, and post-heat treatment duration-on shear strength were systematically analyzed. Experimental results indicated that PA6-CF15 specimens exhibited higher maximum shear loads compared to neat PA6, although they demonstrated more brittle behavior and lower ductility, primarily due to insufficient fiber bridging in the Z-direction. The optimal parameters for maximizing shear strength were identified as a nozzle temperature of 260 degrees C, a layer thickness of 0.15 mm, two outer walls, and 80 min of post-heat treatment. Finite Element Analysis (FEA) corroborated experimental findings by revealing stress concentrations near shear notch regions and confirming that optimized parameters enhance interlayer cohesion. Furthermore, comprehensive surface roughness measurements and Scanning Electron Microscopy (SEM) analyses provided detailed insights into damage progression. Higher nozzle temperatures and thinner layers resulted in smoother surfaces and denser structures, which correlated with improved shear strength. SEM images revealed complex failure mechanisms including fiber-matrix debonding, fiber pullout, matrix cracking, and fiber breakage, with evidence of matrix smearing and ductile drawing. The finite element simulations predicted a maximum shear stress of 151.6 MPa and an average shear stress of 23.4 MPa under optimized conditions, aligning well with experimental observations. Among the examined parameters, layer thickness had the most pronounced influence on shear strength, followed by wall line count and heat treatment duration, while nozzle temperature exhibited a comparatively moderate effect. The findings underscore the critical role of process parameter optimization in enhancing the shear strength and overall mechanical performance of FDM-printed short carbon fiber-reinforced PA6 composites, offering valuable guidance for both academic research and industrial applications.