Hasil Pencarian  ::  Simpan CSV :: Kembali

Abstrak :
Penelitian ini dilakukan untuk mengetahui pengaruh variasi jumlah lapisan kevlar dan impregnasi nano alumina pada serat kevlar terhadap ketahanan balistik komposit laminat hybrid. Terdapat beberapa bahan yang digunakan diantaranya adalah lembaran alumunium 2024-T3, serat kevlar berjenis 29, nano alumina serta resin epoksi.Dalam membuat larutan pengimpregnasi, bahan yang digunakan ialah larutan Polietilen glikol-400 yang kemudian dicampur dengan nano alumina dengan menggunakan magnetic stirrer selama 2 jam. Untuk menurunkan tegangan dan mengoptimalkan proses impregnasi pada serat kevlar, juga digunakan larutan etanol pada campuran larutan impregnasi. Setelah itu serat kevlar direndam dengan campuran yang sudah dibuat lalu dikeringkan. Langkah selanjutnya ialah merakit struktur komposit laminat dengan metode hand layup dengan bantuan epoksi sebagai perekat dan dilanjutkan dengan proses pengeringan di temperatur ruang dengan bantuan epoksi. Hasil percobaan menunjukkan bahwa penambahan jumlah lapisan sangat berpengaruh kepada ketahanan sampel dalam uji balistik maupun impak.Pengaruh dari variasi lapisan dan impregnasi nano alumina dapat meningkatkan ketahan balistik dan impak dari sampel.Hal ini dianalisis berdasarkan beberapa pengujian seperti pengamatan visual dan foto makro. Di sisi lain pengujian ketahan balistik juga diikuti dengan pengukuran diameter perforasi sekaligus tingkat kedalaman penetrasi yang dibentuk akibat proyektil. ...... The goals of this research is to determine the effect of variations in the number of kevlar layers and nano alumina impregnation on kevlar fibres on the ballistic resistance of hybrid laminate composites. There are several materials used; aluminium sheet 2024-T3, kevlar fibre type 29, nano alumina and epoxy resin. In the process of making the impregnation solution, the component that used is Polyethylene glycol-400 solution, who will be mixing with nano alumina using a magnetic stirrer for 2 hours. For optimize the impregnation process in kevlar fibres and reduce the stress, ethanol solution was giving in a mixture of impregnation solution. After the Kevlar layers soaked in a solution, then the kevlar must be dried. The next step is to assemble the laminate composite structure by hand layup method with epoxy resin as an adhesive, and then by drying at room temperature. The experimental results show that increasing the number of layers and adding alumina particle on Kevlar fiber increases the effect of sample durability on ballistic tests and impacts. Those were analyzed based on several assessments; visual observations and macro photographs. On the other hand, ballistic endurance testing is also measured based on the size of the perforation diameter and the depth of penetration formed by the projectile.

Abstrak :
This study aimed to determine the effect of using acrylonitrile butadiene styrene in place of conventional wax material on treatment pattern removal in the investment casting process. There are three controllable process variables that can affect treatment pattern removal, which include temperature increase, holding time and the number of layers of ceramic shell that have been considered for comparison. Comparison among the effects of temperature increase, holding time and numbers of ceramic shell layers on the ceramic shell was analyzed using ANOVA. It was found that temperature increase (Tx), holding time (t) and number of layers of ceramic shell (N) contribute significantly to the length of the crack (l) on the ceramic shell. The crack in the ceramic shell?s surface was analyzed using scanning electron microscope photos. Less layers number cause the increase of crack length. The combination between temperature upraise and longer holding time cause cracking delay. The experimental is conducted by using 3 (three) variants for each of layers number, temperature and holding time. The layers number is ranging between 7-9 layers. Temperature increase from room temperature until 1300oC. The layers number variant is ranging between 180-300 seconds. It was concluded that a longer holding time will result in a more intact ceramic shell, as longer holding times yield short crack lengths.

Abstrak :
This study aimed to determine the effect of using acrylonitrile butadiene styrene in place of conventional wax material on treatment pattern removal in the investment casting process. There are three controllable process variables that can affect treatment pattern removal, which include temperature increase, holding time and the number of layers of ceramic shell that have been considered for comparison. Comparison among the effects of temperature increase, holding time and numbers of ceramic shell layers on the ceramic shell was analyzed using ANOVA. It was found that temperature increase (Tx), holding time (t) and number of layers of ceramic shell (N) contribute significantly to the length of the crack (l) on the ceramic shell. The crack in the ceramic shell’s surface was analyzed using scanning electron microscope photos. Less layers number cause the increase of crack length. The combination between temperature upraise and longer holding time cause cracking delay. The experimental is conducted by using 3 (three) variants for each of layers number, temperature and holding time. The layers number is ranging between 7-9 layers. Temperature increase from room temperature until 1300oC. The layers number variant is ranging between 180-300 seconds. It was concluded that a longer holding time will result in a more intact ceramic shell, as longer holding times yield short crack lengths.