Evaluasi Laju Pengelasan terhadap Mikrostruktur Sambungan Aluminium 5052 dengan menggunakan Metode Friction Stir Welding

Friction stir welding (FSW) adalah salah satu jenis pengelasan yang mampu menyambung bahan paduan aluminium. Pada penelitian sebelumnya telah dilakukan penyambungan aluminium 5052 namun hasil pengujian tarik memperlihatkan penurunan kekuatan sambungan. Sehingga pada studi ini bertujuan untuk mengevaluasi secara focus mikrostuktur yang terbentuk pada sambungan plat aluminium 5052 yang telah dilakukan FSW. Plat aluminium dengan dimensi 150 x 75 mm dengan tebal 6 mm dilas dengan metode FSW, pahat pin berbentuk silinder pada kecepatan putar 1000 rpm dan laju pengelasan 20, 30 dan 40 mm/menit. Penampang hasil las diamati dengan menggunakan mikroskop optic dan Scanning Electron Microscope (SEM). Hasil pengamatan memperlihatkan adanya cacat makro dan perubahan struktur mikro pada sambungan. Cacat ini dipengaruhi desain pin yang tidak tepat sehingga daerah adukan tidak merata yang berakibat sambungan menjadi tidak sempurna.Friction stir welding (FSW) is one type of welding that is able to joining aluminium alloy. In previous studies, aluminium 5052 has been joined, but the results of the tensile test showed a decrease in the strength of the connection. Therefore, in this study the aim is to focus on evaluating the microstructure formed at the 5052 aluminium plate welding join that has been carried out by FSW. Aluminium plates with dimensions of 150 x 75 mm with a thickness of 6 mm were welded by the FSW method, cylindrical pin chisel at a rotational speed of 1000 rpm and welding rates of 20, 30 and 40 mm/minute. The cross section of the weld was observed using an optical microscope and Scanning Electron Microscope (SEM). The results of the observations showed that there were macro defects and changes in the microstructure of the joints. This defect is influenced by the improper design of the pin so that the area of the mixture is uneven which results in an imperfect connectio

Neural Network for Electronic Nose using Field Programmable Analog Arrays

Electronic nose is a device detecting odors which is designed to resemblethe ability of the human nose, usually applied to the robot. The process ofidentification of the electronic nose will run into a problem when the gaswhich is detected has the same chemical element. Misidentification due tothe similarity of chemical properties of gases is possible; it can be solvedusing neural network algorithms. The attendance of Field ProgrammableAnalog Array (FPAA) enables the design and implementation of ananalog neural network, while the advantage of analog neural networkwhich is an input signal from the sensor can be processed directly by theFPAA without having to be converted into a digital signal. Direct analogsignal process can reduce errors due to conversion and speed up thecomputing process. The small size and low power usage of FPAA are verysuitable when it is used for the implementation of the electronic nose thatwill be applied to the robot. From this study, it was shown that theimplementation of analog neural network in FPAA can support theperformance of electronic nose in terms of flexibility (resource componentrequired), speed, and power consumption. To build an analog neuralnetwork with three input nodes and two output nodes only need twopieces of Configurable Analog Block (CAB), of the four provided by theFPAA. Analog neural network construction has a speed of the process0.375 μs, and requires only 59 ± 18mW resources.DOI:http://dx.doi.org/10.11591/ijece.v2i6.150

Characterization, Thermal and Morphological Analysis of Blanched Pretreated Winged Bean Flour

Legumes are a nutritionally dense food source that is widely consumed throughout the world. Winged bean seeds are one of the constituents of nuts. Apart from their use as a culinary item, winged bean seeds can be utilized as a raw material to manufacture compostable coatings and films that help extend the shelf life of food. Biodegradable coatings and films are intended to have physical and chemical qualities that enable them to perform these purposes. This study aimed to determine the chemical composition, morphology, thermal and infrared spectral of pretreated and raw winged bean flour. Proximate analysis revealed how pretreatment decreases winged bean flour's carbohydrate, protein, fat, and ash content. Throughout this period, the water content increased. Thermogravimetric analysis indicates two primary decomposition processes of pretreated winged bean flour showed prominent peaks at 271 oC and 404.2 oC with mass loss of 42.09 % and 32.95 %, respectively. Morphology analysis revealed that the average diameter of granules is the range value of 5-15 µm for pretreated flour. On the other hand, infrared spectral exhibit polysaccharide in pretreated flour is expressed as 1,4 glycosidic linkages, amide I and amide II at bands 1161 cm-1,  1647 cm-1, and 1541 cm-1, respectively

PENGARUH PENGECORAN ULANG TERHADAP KEKUATAN TARIK DAN KEKERASAN PADA ALUMINIUM COR DENGAN CETAKAN PASIR

Penelitian ini bertujuan untuk mengetahui pengaruh pengecoran ulang terhadap kekuatan tarik dan kekerasan pada aluminium. Bahan yang digunakan adalah aluminium yang beredar di pasaran. Material dilebur diatas tungku pengecoran dan dituang pada temperatur 7500C dengan menggunakan cetakan pasir. Hasil pengecoran kemudian dibuat spesimen pengujian tarik menurut standart JIS Z 2201 No. 14 untuk pengujian tarik dan spesimen pengujian kekerasan. Pengecoran ulang dilakukan tiga kali dengan kondisi penuangan yang sama dan masing-masing masing pengecoran dibuat tiga spesimen. Dari hasil pengujian bahwa untuk pengecoran ulang I terhadap pengecoran ulang II kekuatan tarik turun 3.9% dan kekerasannya turun 5.1% dan setelah dilakukan pengecoran ulang III kekuatan tarik turun sekitar 8.9 % dan kekerasannya turun sekitar 27 %. Kesimpulan dari hasil penelitian adalah bahwa pengecoran ulang akan menurunkan kekuatan tarik dan kekerasan aluminium cor. Kata Kunci : Pengecoran Ulang (remelting), kekuatan tarik dan kekerasa

Energy absorbers on the steel plate – rubber laminate after deformable projectile impact

The ability of energy absorption can be used to measure the strength of material against ballistic impact. This paper aims to analyze the rubber plated energy absorption plate that was shot with deformable projectiles. This study was conducted using numerical simulations based on the finite element that have been verified with experimental results. The simulation setting on a steel plate with different hardness with the addition of rubber thickness is prepared as a ballistic test panel. Manufacturing between layers made non fix with the back plate. Panel shot by using 5.56x 45 mm deformable caliber bullet with a distance of 15 m of normal attack angle. The finite element code with Johnson-Cook and Mooney-Rivlin elasto-plastic material models was were employed to perform the simulation study. Simulation results show the energy due to ballistic impact received and absorbed by the panel rises significantly shortly after the collision until reaching a certain number on a single plate where energy will decrease because the projectile successfully penetrated the plate. While on a layered plate, after the projectile succeeded in penetrating the front side plate, the absorption energy reached the maximum number and then remained constant, which caused the projectile not to be able to penetrate the next layer. These findings indicate that the addition of rubber with a layered structure is able to absorb the energy of ballistic impac

Energy absorbers on the steel plate – rubber laminate after deformable projectile impact

The ability of energy absorption can be used to measure the strength of material against ballistic impact. This paper aims to analyze the rubber plated energy absorption plate that was shot with deformable projectiles. This study was conducted using numerical simulations based on the finite element that have been verified with experimental results. The simulation setting on a steel plate with different hardness with the addition of rubber thickness is prepared as a ballistic test panel. Manufacturing between layers made non fix with the back plate. Panel shot by using 5.56x 45 mm deformable caliber bullet with a distance of 15 m of normal attack angle. The finite element code with Johnson-Cook and Mooney-Rivlin elasto-plastic material models was were employed to perform the simulation study. Simulation results show the energy due to ballistic impact received and absorbed by the panel rises significantly shortly after the collision until reaching a certain number on a single plate where energy will decrease because the projectile successfully penetrated the plate. While on a layered plate, after the projectile succeeded in penetrating the front side plate, the absorption energy reached the maximum number and then remained constant, which caused the projectile not to be able to penetrate the next layer. These findings indicate that the addition of rubber with a layered structure is able to absorb the energy of ballistic impac

PENINGKATAN KUALITAS BATIK JAMBE KUSUMA MELALUI PENERAPAN PEWARNA ALAMI SEBAGAI ALTERNATIF PROSES PRODUKSI YANG LEBIH RAMAH LINGKUNGAN

Pembatik dari desa Jambearum kecataman Patebon kabupaten kendal memproduksi batik yang diberi nama batik Jambe Kusuma. Proses pewarnaan batik menggunakan pewarna sintetik menghasilkan limbah yang menimbulkan masalah pada lingkungan. Oleh karena itu diperlukan pengetahuan mengenai cara membuat dan mengaplikasikan pewarna alam yang lebih ramah lingkungan pada batik. Penelitian ini bertujuan untuk mengeksplorasi bahan-bahan alam yang dapat dipergunakan sebagai pewarna pada batik. Bahan-bahan alam yang dieksplorasi untuk dipergunakan sebagai pewarna adalah sabut kelapa, kulit manggis, kulit  bawang merah, kunyit dan batang pohon mangga. Sedangkan fixer adalah kapur, tawas dan tunjung. Dari hasil percobaan dapat diperoleh hasil bahwa kelima jenis bahan dapat dijadikan bahan pewarna alam dan fixer tunjung memberikan warna paling tua untuk kelima jenis bahan pewarna.   Kata kunci: batik, kendal, pewarna alam

Pengaruh Variasi Temperatur Tuang pada Pengecoran Daur Ulang Al-Si terhadap Struktur Mikro dan Kekerasan dengan Pola Styrofoam

Penelitian ini bertujuan mengetahui pengaruh temperatur tuang pada pengecoran daur ulang Al-Si terhadap struktur mikro dan kekerasan dengan menggunakan pola Styrofoam. Material aluminium dari velg bekas diplih sebagai bahan utama dalam penelitian ini. Parameter yang digunakan dalam pengecoran adalah temperatur tuang dengan variasi 660, 710, dan 760oC. Pengamatan struktur mikro dan pengukuran SDAS menggunakan mikroskop optic dan image analysis software. Pengujian kekerasan dilakukan untuk mengetahui sifat mekanis material. Hasil pengujian menunjukkan SDAS semakin kasar atau meningkat 56 % pada temperatur tuang 760o C sehingga mengalami peningkatan kekuatan mekanik sebesar 2.59%

The Influence of Single and Double Steel Plate Hardness on Fracture Behavior after Ballistic Impact

This study aims to determine the ballistic characteristics of the two steel plates with different hardness levels and mix in the form of layered in non-permanent constructions. Ballistic testing by caliber 5.56 × 45 mm deformed full metal jacket on a sample plate with each a thickness of 6 mm at a distance of 15 m with a normal angle of attack. The results of ballistic testing on both single plates are they can be pierced by a projectile. While for the layered plate, projectile can only penetrate the front side of the plate. The characteristic of each hole that is formed shows the difference caused by the level of hardness of the plate. On the rear part of the plate, a bulge appears because of an impact from the front side of the plate. In the Soft Plate appear high petals around the hole on the front side with the microstructure deformed on the crater walls. While the hard plate forms small petals on the back side and slightly deformed crater walls. The Soft plate is perforated due to deformation with petaling and fragmentation mechanism, while the hard plate is perforated due to plugging mechanism and adiabatic shear band and cracked

Analysis projectile performance in ballistic tests using compressed air gun

Ballistic resistance is affected by the projectile and armor material used. The character and behavior of the projectile affects its ability to damage and penetrate armor. The velocity, mass and shape of the projectile are the main factors in determining the ability of the projectile to penetrate armor in this case the target plate. Therefore, this study aims to determine and analyze the effect of projectile mass and shape on the velocity with which it penetrates the armor material using a compressed air gun. Armor material as a ballistic test target using carbon steel plate with a thickness of 0.8 mm; 1.2 mm and 1.8 mm. Projectiles of lead materials with different masses and shapes are fired from the air gun under controlled air pressure, set at 2000 Psi, 3000 Psi, and 4000 Psi to provide thrust in the barrel. The plat target is placed at a distance of 5 m from the air gun. Speed gauges are placed after the air gun and after the target plate to determine the projectile's rate before and after passing through the target plate. The test results concluded that the velocity of the projectile ejected from the compressed air gun was influenced by the magnitude of the pressure and the mass of the projectile. The mass of the projectile has a more dominant effect on the velocity of the projectile compared to the amount of pressure applied. Different projectile shapes with the same mass have no significant effect on the velocity. However, the heavier mass projectile outperforms the lighter mass projectile through the target plate. It is required the right combination of velocity and mass of the projectile to be able to penetrate the target plat