Bakır ve Silisyum İlavelerinin Al-25Zn Alaşımının CVD Al2O3 Kaplamalı Takımlarla Tornalanmasında İşlenebilirliğe Etkisinin İncelenmesi

Abstract

In this study, Al-25Zn-3Cu and Al-25Zn-3Cu-3Si alloys were obtained by adding Copper (Cu) and Silicon (Si) to Al-25Zn alloy using induction melting and permanent mold casting method. Microstructural and mechanical properties of alloys were determined. The internal structure of Al-25Zn consisted of α and η phases, while the internal structure of Al-25Zn-3Cu consisted of α, α + η and θ phases. In addition to these phases, eutectic and primary silicon particles were observed in the internal structure of Al-25Zn-3Cu-3Si. It was determined with the addition of Cu and Si that the hardness, yield and tensile strength of the alloy was increased and the breaking elongation was reduced. In addition, the machinability of these alloys in turning process was investigated experimentally and the effect of Cu and Si on machinability was revealed. As a result of cutting experiments, the highest cutting force was measured in Al-25Zn-3Cu-3Si alloy while the lowest cutting force was measured in Al-25Zn-3Cu alloy. The highest surface roughness value was measured in the Al-25Zn-3Cu-3Si alloy at all cutting speeds, while the lowest was in the Al-25Zn alloy. Figure A. Experimental setupPurpose: In this study, it was aimed to investigate the effect of Cu and Si on the machinability properties of Al-25Zn alloy.Theory and Methods: Firstly, microstructural and mechanical properties of alloys were determined by optical microscope and universal test methods, respectively. Cutting force and roughness values were measured with the Kistler dynamometer and surface roughness measuring device, respectively. The cutting performance of CVD-Al2O3 inserts was evaluated by imaging the adhesion formed at the insert with SEM (Scanning Electron Microscope).Results: The addition of Cu and Si to the Al-25Zn alloy increased the hardness, yield and tensile strength of the alloy, while reducing the breaking elongation. Si element was been found to worsen the machinability properties of alloy, but copper improved. Conclusion:In this study, the effect of Cu and Si on microstructural, mechanical and machinability properties of Al25-Zn alloy was presented. The results show that Cu and Si have a significant effect on the microstructural and mechanical properties and cutting performance of the alloy.

Comparison of Machinability Performances in Milling of Al-7Si-Mg and Al-7Si-0.6Mg Alloys

“…5-7). This was thought to be due to the formation of more Mg2Si precipitates in the microstructure of the Al-7Si-0.6Mg alloy and the decreased in EF depending on the increase in Mg content [2,16] It was observed that the formation of BUL and BUE in cutting tools reduced with the increment in V. The tool/chip contact surface area decreased depending upon the increment in V. At the same time, high cutting temperatures occurred due to high V in Al-based alloys and plastic deformation of the chip was facilitated and BUL and BUE formation were reduced [29,30]. It was observed that the formation of BUL and BUE in the cutting tool increased with the increment in f. It was thought that this situation was caused by the high volume of metal removal rate that caused high c) d) pressure and CFs and the increase in the tool/chip interface contact area [31,32].…”

“…5 and 6). The tool/chip interface temperature increased with the increment of V. Due to this temperature increment, the YS of the machined material reduced and the formation of plastic deformation became easier and the CF reduced [28,29]. It was thought that the CF increased due to the increment in the f parameter and the increase in the volume of chip removed in unit time during cutting and the power required for plastic deformation [2].…”

Al-9Si-0.1Sr-0.6Mg Alaşımının Tornalanmasında İşlenebilirlik Karakteristiklerinin Araştırılması

“…250 m/dak sabit kesme hızında ilerlemenin 0,05 mm/dev'den 0,25 mm/dev'e artması ile kesme kuvveti ve yüzey pürüzlülüğü sırasıyla %189,75 ve %119,08 oranında artarken, sabit 550 m/dak kesme hızında bu değerlerin sırasıyla %142,50 ve %567,24 oranında arttığı tespit edilmiştir.İlerlemenin artmasına bağlı olarak birim zamanda kaldırılması talaş hacminin artması kesme kuvvetini arttırmaktadır. Aynı zamanda ilerlemedeki bu artış, takım-talaş arayüzeyinde sürtünme yüzey alanının artmasına neden olarak kesme kuvvetini arttırdığı düşünülmektedir(Bayraktar & Demir, 2020; Bayraktar vd., 2020;Bayraktar & Çamkerten, 2020; Korkut & Dönertas, 2007). Şekil 3 ve 4'teki grafikler incelendiğinde en düşük kesme kuvveti ve yüzey pürüzlülüğü değerlerinin testler kapsamında kullanılan en yüksek kesme hızı (550 m/dak) ve en düşük ilerleme değerlerinde (0,05 mm/dev) ölçüldüğü tespit edilmiştir.Şekil 4.…”