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Pengaruh Rapat Arus dan Waktu Anodizing Terhadap Ketebalan Lapisan Aluminium Oksida pada Aluminium Paduan AA 2024-T3 Fajar Nugroho
FLYWHEEL : Jurnal Teknik Mesin Untirta Volume I Nomor 2, November 2015
Publisher : Universitas Sultan Ageng Tirtayasa

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (465.2 KB) | DOI: 10.36055/fwl.v1i1.534

Abstract

Aluminium paduan AA 2024-T3 banyak diaplikasikan secara luas pada industri pesawat terbang karena memiliki sifat mekanik yang baik seperti ; bobot yang ringan, kekuatan tarik relatif tinggi dan adanya ketahanan korosi yang disebabkan pembentukan lapisan pasif berupa aluminium oksida. Namun demikian lapisan pasif yang terbentuk secara alami ini memiliki ketebalan yang relatif sangat tipis. Salah satu usaha untuk meningkatkan ketebalan aluminium oksida adalah dengan proses anodizing. Penelitian ini bertujuan mempelajari pengaruh rapat arus dan waktu anodizing dalam meningkatkan ketebalan lapisan aluminium oksida pada aluminium paduan AA 2024-T3Proses anodizing menggunakan larutan asam sulfat 10% dengan rapat arus antara 0,75 A/dm2 sampai 3 A/dm2 dengan waktu pencelupan 30, 40, 50 dan 60 menit. Selanjutnya laju ketebalan lapisan alumimium oksida yang terbentuk diukur dengan menggunakan alat Dual Scope Mpor dalam skala μm. Sebagai data pendukung dilakukan uji komposisi, uji struktur mikro, uji kekerasan Vickers dan uji tarik. Hasil penelitian ini menunjukan bahwa ketebalan lapisan aluminium oksida pada aluminium paduan AA 2024-T3 dapat ditingkatkan dengan proses anodizing. Anodizing mampu meningkatkan ketebalan lapisan aluminium oksida sehingga laju korosi menurun.
STUDI KOMPARASI PENGARUH VARIASI ARUS PENGELASAN TERHADAP KEKUATAN IMPAK, KEKERASAN, DAN STRUKTUR MIKRO SAMBUNGAN LAS PEGAS DAUN BAJA SUP 9 PADA PROSES LAS SMAW Fajar Nugroho
Angkasa: Jurnal Ilmiah Bidang Teknologi Vol 9, No 2 (2017): November
Publisher : Institut Teknologi Dirgantara Adisutjipto

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (234.775 KB) | DOI: 10.28989/angkasa.v9i2.181

Abstract

 Pegas adalah suatu komponen yang berfungsi untuk menerima beban dinamis dan memberikan kenyamanan dalam berkendara. Permasalahan yang sering dialami oleh pegas daun adalah patah akibat beban lebih atau kondisi jalan yang kurang baik. Penanganan pada hal seperti ini adalah penyambungan menggunakan las SMAW.Penelitian ini bertujuan untuk mengetahui pengaruh variasi arus pengelasan terhadap kekuatan impak, kekerasan dan Struktur mikro. Jenis las yang digunakan adalah las SMAW. Variasi arus pengelasan yang digunakanadalah 100 A, 120 A dan 140 A. Jenis kampuh yang digunakan adalah jenis kampuh V.Hasil uji kekuatan impak tertinggi diperoleh pada variasi arus 100 A yaitu sebesar 1,698 J/mm2. Hasil uji kekerasan tertinggi diperoleh pada variasi arus 140 A yaitu sebesar 355,338 HVN. Struktur mikro pada daerah las memiliki ukuran butiran yang semakin besar dan struktur perlit yang semakin banyak untuk variasi arus 140 A. 
Influence of Biomass Based Carbon Black as Filler Composite on Tensile and Impact Strength Nurfi Ahmadi; Fajar Nugroho
Angkasa: Jurnal Ilmiah Bidang Teknologi Vol 12, No 2 (2020): November
Publisher : Institut Teknologi Dirgantara Adisutjipto

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (669.448 KB) | DOI: 10.28989/angkasa.v12i2.539

Abstract

Carbon blacks (CB), derived from agricultural waste, bamboo stem, coconut shells  and oil palm empty fiber bunch, were obtained by pyrolysi used as filler in epoxy composites. The aim of this study was to identify the effect of biomass based carbon black on the tensile and impact strength  carbon black – epoxy composite. In this research, carbon black was biomass based. The matrix was epoxy resin Bakelite EPR 174 and epoxy hardener versamid 140 while, the methodology for making the composite was hand lay-up method. The composite were made at 5, 10, 15, 20 volume percentage  carbon black then the composite tested with the tensile and impact strength. The highest tensile strength was 44,65 MPa 5 volume percentage  carbon black and the highest impact strength was 5.47 MPa volume percentage  carbon black. While, based on the result of Scanning Electron Microscope (SEM) analysis showed there were agglomeration at the particle of carbon black, pull out, and void.
INFLUENCE OF PANDANUS TECTORIUS LEAF FIBER ON MECHANICAL PROPERTIES AND MORPHOLOGY OF POLYPROPYLENE COMPOSITE Fajar Nugroho; Sudarmanto Sudarmanto
Angkasa: Jurnal Ilmiah Bidang Teknologi Vol 12, No 1 (2020): Mei
Publisher : Institut Teknologi Dirgantara Adisutjipto

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2757.963 KB) | DOI: 10.28989/angkasa.v12i1.536

Abstract

Natural fiber reinforced polymer composites are widely developed because of their relative low price and eco-friendly. One of natural fiber sourches is pandanus tectorius leaf.  This study aimed to determine the effect of variations in fiber volume fraction on tensile strength, impact strength, bending strength and morphological on sea pandanus fibers- polypropylene composites.Tensile test spesimen refer to ASTMD 638, impact test spesimen refes to ASTMD 5942-96, bending test spesimen refer to ASTMD 790 -02. The increasing of the volume fraction increased  the tensile strength and impact strength. The tensile test results showed the highest tensile strength results for composites with a volume fraction of 35% was 25.82 MPa. The impact test results showed that the highest impact strength was obtained in the 35 % volume fraction of 0.0062 Joule/mm2. The bending test results showed that the highest bending strength was obtained in the 20% volume fraction of 24.96 MPa. Based on SEM test results, there were voids, cracks, fibers pull out on the composite.
PENGARUH RAPAT ARUS ANODIZING TERHADAP NILAI KEKERASAN PADA PLAT ALUMINIUM PADUAN AA SERI 2024-T3 Fajar Nugroho
Angkasa: Jurnal Ilmiah Bidang Teknologi Vol 7, No 2 (2015): November
Publisher : Institut Teknologi Dirgantara Adisutjipto

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (224.803 KB) | DOI: 10.28989/angkasa.v7i2.147

Abstract

Aluminum alloy AA 2024-T3 is widely applied in the aircraft industry because it has good mechanical properties such as; light weight, good conductivity and the corrosion resistance. However Aluminium 2024-T3 susceptible to wearing. One method to improve the wear resistance o f AA 2024-T3 is the anodizing process. The aims of this research to study the effect of current density and anodizing time against the hardness of aluminum alloy AA 2024-T3. The process of anodizing was carried out using 10 percent sulfuric acid solution with the current density of 1.5 Ampere per decimeters square, 3.0 Ampere per decimeters square and 4.5 Ampere per decimeters square with immersion times of 30, 40, 50 and 60 minutes. Furthermore, the surface hardness was measured by using the Vickers hardness test method. As the supporting data the composition of the test conducted, testing the microstructure, and vickers hardness test. This study shows that the surface hardness of aluminum alloy AA 2024-T3 is influenced by the current density and anodizing time with varying values. Its shows that higher current density o f the anodizing caused optimal time tends to be short. The longer anodising time it will produce greater layer of aluminum oxide.
STUDI PENGARUH PROSES MANUFAKTUR KOMPOSIT BERMATRIK EPOKSI TERHADAP KEKUATAN TARIK DAN IMPAK PADA KOMPOSIT HYBRID BERPENGUAT SERBUK KAYU ALBASIA DAN SERAT GELAS Fajar Nugroho
SENATIK STT Adisutjipto Vol 2 (2016): Peran Teknologi dan Kedirgantaraan Untuk Meningkatkan Daya Saing Bangsa
Publisher : Institut Teknologi Dirgantara Adisutjipto

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.28989/senatik.v2i0.65

Abstract

A composite material is very efficient to use at a structure which needs a combination between strength and stiffness and light weight. The advantage of composite material compared to a metal is corrosion resistance, accessible, and reasonable price. This study aims to determine the tensile and impact strength composites of the epoxy matrix composite reinforced by glass fiber and albsia sawdust.The composites were made using variations of stirring time 15 minutes and 30 minutes with a stirring speed of 658 rpm and 858 rpm. The composite were made using variations of the drying temperatures 40ºC, 50ºC, 60ºC, 70ºC, and the room temperature. The reinforced materials is used  albasia sawdust and woven glass fiber. The matrix was Epoxy Resin Bakelite EPR 174 and Epoxy Hardener V-140. The methodology for making the composite test specimens particles was hand lay-up (open mold). The highest tensile strength testing on a composite was 37.92 MPa with a stirring time of 30 minutes and 858 rpm stirring rotation. For the impact testing, the highest visible impact at 0.0024 J/mm² in the composite with a stirring time of 15 minutes and 858 rpm stirring rotation. Through this test, it was obtained the highest tensile strength of 43.03 MPa in the composite with 50ºC drying temperature variation. Meanwhile, the composites with 60ºC drying temperature variation had the highest impact strength with a value of 0.0037 J/mm². The composite material composition and morphology of the fracture were analyzed by SEM observation.