Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2025Effect of Chromium Addition on ZA40 Alloy Fabricated by Powder Metallurgy Method
Aydin, Kemal
The aim of this study is to develop and investigate the properties of chromium powder-reinforced metal-metal composites using powder metallurgy methods with a ZA40 alloy matrix. To analyze the effect of varying chromium particle amounts on ZA40-Cr composites, samples with chromium weight percentages of 5%, 10%, and 15% were produced. To ensure uniform distribution of chromium particles, the matrix and composite powders were mixed in ball mills for five hours. These powders were then hot-pressed under an argon gas atmosphere at 500°C and 500 MPa pressure for two hours to form the samples. The samples were evaluated by determining the microstructure, hardness, density, and tensile properties of the ZA40-Cr metal-metal composites with varying chromium content. Porosity and relative density results revealed that increasing Cr content increased porosity while reducing relative density. Hardness measurements showed that the sample with 10% Cr addition exhibited the highest hardness value (182 Brinell). However, increased porosity in the 15% Cr sample caused a decline in hardness. Tensile strength tests indicated that the sample with 10% Cr addition achieved the highest strength (240 MPa). The results demonstrated that the reinforcement of the ZA40 matrix with Cr particles at specific ratios enhanced the mechanical performance, but that excessive Cr content adversely affected the properties due to increased porosity. The optimum Cr content was determined to be 10%, providing the best mechanical properties. This study highlights the potential of ZA40-Cr composites as cost-effective and high-performance materials for engineering applications.
- MakaleYalnız künye2025The effect of welding parameters on weld bead geometry in gas tungsten arc welding applications by response surface methodology model
Yildirim, Mehmet Serkan; Ayhan, Emre; Aydin, Kemal; Durgutlu, Ahmet
This study examines the effects of tungsten electrode sharpening angle, torch angle, and arc length on weld bead geometry in gas tungsten arc welding (GTAW). Low-carbon steel plates (4 mm thickness) were welded using ER70S-6 filler wires (2 mm diameter). Experimental analyses and response surface methodology (RSM) revealed that increasing the electrode sharpening angle enhances penetration depth, while reducing the torch angle widens the bead. Longer arc lengths decrease penetration but increase bead width. Validation tests confirmed the accuracy of the RSM models, showing an average deviation of 1.14%. Analysis of variance highlighted the statistical significance of linear, quadratic, and interaction terms in the models. The findings provide critical insights for optimizing GTAW parameters, improving weld quality, and advancing process control, thereby contributing both practical and academic value to welding research.
- MakaleYalnız künye2022Characterization of the Welding Zone of Automotive Sheets of Different Thickness (DP600 and DP800) Joined by Resistance Spot Welding
Aydin, Kemal; Hidiroglu, Mehtap; Kahraman, Nizamettin
Automotive industry in recent years, has gained great importance. In line with this, DP600 and DP800 dual-phase steels and the electrical resistance spot welding method were used in the study. During the experimental trials, different welding currents (6, 7, and 8 kA) were selected and all other welding parameters were kept constant. The effects of the welding parameters on microstructure, hardness, tensile-shear, and cross-tensile strength were analyzed. In the phase measurements, 27.06–29.97% martensite and 70.73–73.85% ferrite phases were found. When the hardness values in the HAZ regions were examined, it was seen that the highest hardness values were 356 ± 5 HV in the DP600 and 451 ± 5 HV in the DP800 with a current intensity of 6 kA. Consequently, it was determined that tensile-shear and cross-tensile strengths had increased in parallel with the increase in the welding current and the highest values were determined as 8 kA–15.91 kN in tensile shear and 8 kA–4.91 kN in cross-tensile strength.