Studi Pengaruh Waktu Degassing dan Laju Pendinginan terhadap Struktur Mikro dan Porositas pada Pengecoran Paduan Aluminium 6061 dengan Metode Sand Casting

Alexander, Boby (2018) Studi Pengaruh Waktu Degassing dan Laju Pendinginan terhadap Struktur Mikro dan Porositas pada Pengecoran Paduan Aluminium 6061 dengan Metode Sand Casting. Undergraduate thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Paduan aluminium banyak digunakan dalam dunia industri seperti pada pembangkit tenaga, militer, konstruksi, barang sehari-hari serta dalam bidang transportasi termasuk pada industri pesawat terbang. Hal ini karena paduan aluminium memiliki sifat mekanik dan ketahanan korosi yang baik serta berat spesifik yang rendah. Proses degassing (2 menit, 5 menit dan 8 menit) dan modifikasi laju pendinginan (13 oC/menit, 20 oC/menit dan 26 oC/menit) dilakukan untuk mengurangi porositas dan ukuran Dendrite Arm Spacing (DAS) yang lebih kecil. Metode pengecoran yang digunakan adalah sand casting dan peleburan menggunakan electric furnace pada temperatur 720 oC. Struktur mikro paduan menunjukkan ukuran DAS berkurang dari 137,3 µm menjadi 87,58 µm. Tingkat porositas turun dari 3,58% pada waktu degassing 2 menit dan laju pendinginan 13 oC/menit menjadi 1,8% pada waktu degassing 5 menit dan laju pendinginan 26 oC/menit. Hasil pengujian kekuatan tarik menunjukkan bahwa nilai kekuatan tarik naik ketika ukuran DAS dan tingkat porositas semakin kecil. Nilai kekuatan tarik paling tinggi adalah 105,9 dan paling rendah adalah 70,53 MPa. ================= Aluminum alloys are widely used in many industries such as power generator, military, construction and transportation including the aircraft industry. This is because aluminum alloys have good mechanical properties and corrosion resistance as at the same time also giving a low specific weight. The degassing process (2 minutes, 5 minutes and 8 minutes) and cooling rate modifications (13 oC / min, 20 oC / min and 26 oC / min) were performed to reduce both the porosity and the size of Dendrite Arm Spacing (DAS). The casting method used in this research is sand casting and raw material were melted using electric furnace at 720 oC. The microstructural images showed the dendrite arm spacing size are decreased by size from 137.3 μm to 87.58 μm obtained from cooling rates of 13 oC / min and 26 oC / min respectively. In the other hand, the level of porosity are also decreased from 3.58% at 2 min degassing and the cooling rate of 13 oC / min to 1.8% at 5 min degassing and 26 oC / min cooling rate. Furthermore, the tensile test results shows that the value of tensile strength increases when the DAS size and porosity level are smaller. The highest ultimate tensile strength value is 105.9 and the lowest is 70,53 MPa.

Item Type: Thesis (Undergraduate)
Additional Information: RSMt 671.252 Ale s
Uncontrolled Keywords: aluminium, degassing, laju pendinginan, struktur mikro, porositas, kekuatan, aluminum, degassing, cooling rate, microstructure, porosity, tensile
Subjects: T Technology > TL Motor vehicles. Aeronautics. Astronautics > TL671.6. Materials--Fatigue.
T Technology > TN Mining engineering. Metallurgy > TN690 Metallography. Physical metallurgy
T Technology > TS Manufactures
Divisions: Faculty of Industrial Technology > Material & Metallurgical Engineering > (S1) Undergraduate Theses
Depositing User: Boby Alexander
Date Deposited: 26 Nov 2018 03:39
Last Modified: 26 Nov 2018 03:39
URI: http://repository.its.ac.id/id/eprint/53048

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