Mekanik alaşımlama ve ekstrüzyon sonrası $Al_4C_3$ oluşumunun incelenmesi

Bu çalışmada saf Al-C tozları yatay atritörde MA işlemine tabi tutulmuştur. Su soğutmalı sistemde, tozlara 20:1 bilya toz oranında ve 600 dev/dak. öğütme hızında 2 saat MA uygulanmıştır. Daha sonra tozlar 1200 MPa basınç altında preslenerek kütle numuneler elde edilmiştir. 500 gram MA yapılmış tozlarda %11 oranında 475circ C’de ekstrüzyon işlemine tabii tutulmuşlardır. Ekstrüzyon sonrası elde edilen 10 mm çapındaki çubuk deneylerde kullanılmıştır. Deney numuneleri 550circ C’de, 2-64 saat arasında ve argon atmosferinde sinterlenmişlerdir. MA ve ısıl işlemler sonrası SEM, TEM ve EDAX analizi yapılmış, $(Al_4C_3)$ oluşumu tespit edilmeye çalışılmıştır. SEM TEM ve EDAX incelemeleri sonunda preslemenin ve ekstrüzyonun $(Al_4C_3)$ oluşumunda etkin parametreler olduğu tespit edilmiştir. TEM sonuçları, sinterlenen malzemelerde $(Al_4C_3)$ dönüşümünün gerçekleştiğini göstermektedir.

Examination of $Al_4C_3$ formation after mechanically alloying and extrusion

In this study, pure Al-C powders were mechanically alloyed in the horizontal atritor. In the water cooling system mechanically alloying process was applied to the powders at 20:1 ball/powder ratio and at 600 rev/min. for 2 hours. Then, bulk specimens were obtained through pressing the powders at 1200 MPa. 500 g mechanically alloyed powders were extruded for 11 % ratio at 475°C. After extrusion, the rod with 10 mm diameter was used in the experiments. The specimens were sintered at 550°C for 2-64 hr under argon gas atmosphere. After MA and heat treatments; it was aimed to determine $(Al_4C_3)$ formation via SEM, TEM and EDAX analysis techniques. These examinations revealed that pressing and extrusion are effective parameters in $(Al_4C_3)$ formation. $(Al_4C_3)$ transformation in the sintered specimens was supported by the TEM analysis.

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