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Abstrak :
Baja sering digunakan sebagai material penyusun pada badan pelindung kendaraan taktis karena ketahanan balistiknya yang baik. Dengan densitasnya yang tinggi, memicu pengembangan material pengganti dengan densitas yang lebih rendah namun tetap dapat menahan penetrasi peluru. Salah satunya adalah komposit aluminium dengan penguat SiC. Pada penelitian sebelumnya, pelat komposit Al-6Mg-xZn dengan variasi 6, 9 wt.% Zn berpenguat 10 dan 20 vol.% SiC telah berhasil menahan peluru tipe III, namun masih mengalami retak dibagian belakang. Oleh karena itu, perlu adanya modifikasi matriks agar menghasilkan komposit yang lebih tangguh seperti penambahan Cr. Pada penelitian ini dipelajari komposit Al-11Zn-7Mg berpenguat 10 vol.% SiC dengan variasi kadar Cr sebesar 0, 0.043, 0.051, 0.083 wt.% yang difabrikasi melalui metode squeeze casting. Untuk meningkatkan sifat mekanis, pelat komposit kemudian diberikan laku pelarutan pada temperatur 450 oC selama 1 jam yang dilanjutkan dengan laku penuaan pada temperatur 130 oC selama 102 jam. Karakterisasi yang dilakukan pada pelat komposit yaitu pengujian komposisi kimia menggunakan Optical Emission Spectrometry (OES), analisis struktur mikro dengan mikroskop optik (OM), Scanning Electron Microscopy (SEM) dan Energy Dispersive X-Rays (EDX), perhitungan persentase porositas dan pengukuran Secondary Dendrite Arm Spacing (SDAS) menggunakan perangkat lunak Image Pro Plus, pengujian kekerasan Rockwell B, serta pengujian impak metode charpy. ......Steel has been used as the constituent material for body of tactical vehicle due to its high ballistic resistance. But, steel has high density that triggered developments of lighter materials with high hardness and high impact energy such as SiC strengthened aluminium composites. Previous research has shown that 10 and 20 vol.% SiC strengthened Al-6Mg-xZn with variation 6 and 9 wt.% Zn could withstand type III bullets, but cracks remained at the back of the plate. Therefore, matrix modification is needed in order to produce thougher aluminium composite such as addition of Cr. This research used Al-11Zn-7Mg as matrix and 10 vol.% SiC as reinforcement with variation of 0, 0.043, 0.051 and 0.083 wt.% Cr which are fabricated by squeeze casting method. To improve the mechanical properties, the composite plates were solution treated at 450°C for 1 hour then aged at 130 oC for 102 hours. The characterization consisted of chemical composition testing by using Optical Emission Spectrometry (OES), microstructure analysis by using Optical Microscope (OM), Scanning Electron Microscopy (SEM) and Energy Dispersive X-Rays (EDX), porosity calculation and Secondary Dendrite Arm Spacing (SDAS) measurement by using Image Pro Plus software, hardness testing by using Rockwell B and impact testing by using charpy method. The results showed that addition of Cr from 0 to 0.083 wt.% increased the hardness of composite from 58.8 to 61.8 HRB and decreased the impact values from 11290.4 to 10131.8 J/m2. The increase in hardness was due to solid solution strengthening of Cr in Al-Zn-Mg matrix as well as reduction of SDAS from 21.6 to 17.1 μm respectively from the addition 0.043 to 0.083 wt.% Cr. Ageing at 130°C significantly increased the hardness of the composites from 83.1 to 90.7 HRB, however, Cr did not give impact on the precipitation processes. Along with the increasing hardness, the impact properties decreased which indicated reduction of toughness.

Abstrak :
ABSTRAK
Material badan pelindung kendaraan tempur umumnya terbuat dari baja yang memiliki kekerasan dan kekuatan impak yang tinggi. Namun karena densitasnya yang tinggi, dilakukan pengembangan material dengan densitas yang jauh lebih rendah namun tetap dapat menahan penetrasi peluru. Salah satunya adalah dengan mengembangkan metal matrix composite dengan matriks aluminium. Pada penelitian sebelumnya pelat komposit aluminium berpenguat SiC telah berhasil menahan peluru tipe III, namun masih mengalami retak dibagian belakang. Oleh karena itu, pada penelitian ini dilakukan penambahan unsur Ti dengan tujuan untuk meningkatkan ketangguhan matriks komposit melalui mekaisme penguatan batas butir. Komposit dengan matriks Al-11Zn-8Mg berpenguat 10 vol.% SiC dengan variasi kadar Ti sebesar 0, 0.018, 0.029, 0.224 wt.% difabrikasi menggunakan proses squeeze casting. Pelat komposit diberi laku pelarutan pada temperatur 450 oC selama 1 jam, dilanjutkan dengan laku penuaan pada temperatur 130 oC selama 102 jam untuk meningkatkan ketangguhannya. Karakterisasi yang dilakukan pada pelat komposit yaitu, pengujian komposisi kimia menggunakan Optical Emission Spetroscopy (OES), pengujian kekerasan menggunakan metode Rockwell B, pengujian impak menggunakan metode Charpy, pengamatan struktur mikro menggunakan mikroskop optik dan Scanning Electron Microscope (SEM) yang dilengkapi dengan Energy Dispersive X-Ray Spectroscopy (EDS). Hasil pengujian tersebut menunjukkan bahwa dengan peningkatan kadar Ti akan meningkatkan kekerasan pelat komposit melalui mekanisme penghalusan dendrit. Seiring dengan meningkatnya nilai kekerasan pelat komposit, harga impaknya menurun yang menunjukkan penurunan ketangguhan komposit. Penuaan meningkatkan kekerasan komposit secara signifikan dengan pembentukan endapan MgZn2. Adanya kandungan Ti menurunkan solute-vacancy-complexes sehingga menghambat mobilitas Mg dan Zn untuk membentuk presipitat.

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ABSTRACT
Materials for military vehicle are usually made of steel which has high hardness and high impact properties. Because of its high density, development of lighter materials with high hardness and high impact energy such as aluminium composites is done. Previous research has successfully produced SiC-strengthened aluminium composites that were able to withstand type III bullets, but cracks remained at the back of the plate. Therefore, in this research, Ti was added in order to increase the toughness of the composite matrix by grain boundary strengthening. This research used Al-11Zn-8Mg as matrix and 10 vol.% SiC as reinforcement with Ti addition of 0, 0.018, 0.029 and 0.224 wt.% which were fabricated by squeeze casting method. The composites were solution treated at 450 oC for 1 hour, then aged at 130 oC for 102 hours. Material characterization consisted of chemical composition test by using Optical Emission Spectroscopy (OES), hardness test by using Rockwell B method and impact test using Charpy method, microstructural analysis by using optical microscope and Scanning Electron Microscope (SEM) equipped with Energy Dispersive X-Ray Spectroscopy (EDS). The results showed that addition of Ti increased the hardness by grain refining mechanism. The increase in hardness was followed by the decrease in toughness. The hardness significantly increased by aging process due to the formation of MgZn2 precipitates. Addition of Ti lowered the number of solute-vacancy-complexes which decreased the mobility of zinc and magnesium to form precipitate.

Abstrak :
Salah satu kekuatan militer Indonesia yaitu Industri pertahanan nasional khususnya kendaraan tempur membutuhkan adanya modernisasi dari sisi material untuk meningkatkan mobilitas dan efisiensi penggunaan energi saat digunakan di medan perang. Namun, tidak mengurangi atau bahkan diharapkan melebihi dari kekuatan mekanis dari baja tahan peluru yang saat ini masih menjadi andalan dalam manufaktur kendaraan militer Penelitian ini akan berfokus pada komposit laminat dengan matriks logam AA7075 – T6 dengan penguat serat karbon dengan variasi adanya perlakuan pencanaian dingin pada matriks dan kuantitas serat penguat karbon yang divariasikan jumlahnya 10, 20, hingga 30 lembar. Masing-masing sampel diuji balistik pada 2 tingkatan yang berbeda, pistol dengan proyektil 9 mm dan senapan dengan proyektil 5,56 mm. Perlakuan pencanaian dingin sebesar 42% ini menunjukkan adanya peningkatan kekuatan mekanis seperti kekuatan tarik dan kekerasan pada matriks aluminium, tetapi mengurangi performa balistik komposit khususnya di level II dan level III akibat penurunan ketebalan. Penambahan serat karbon terbukti dapat meningkatkan performa balistik komposit di level II dan mengurangi terbentuknya mode kegagalan di level III. Sampel komposit berhasil menahan proyektil pada pengujian balistik dengan pistol dan proyektil 9 mm, tetapi gagal pada pengujian dengan senapan dan proyektil 5,56 mm, dengan mode kegagalan yang timbul berupa petaling, shear plugging, delamination, bulging, fiber breakage, dan crack. ......One of Indonesia's military strengths is the national defense industry, especially combat vehicles, which require modernization in terms of materials to increase mobility and efficient use of energy when used on the battlefield. However, it does not reduce or is even expected to exceed the mechanical strength of bullet-resistant steel which is currently still a mainstay in military vehicle manufacturing. This research will focus on laminated composites with an AA7075 - T6 metal matrix with carbon fiber reinforcement with variations in the cold rolling treatment of the matrix. and the quantity of carbon reinforcing fiber varied in number from 10, 20, to 30 layers thick. Each sample was tested for ballistics at 2 different levels, a pistol with a 9 mm projectile and a rifle with a 5.56 mm projectile. This 42% cold rolling treatment shows an increase in mechanical strength such as tensile strength and hardness in the aluminum matrix, but reduces the overall ballistic performance especially at level II and level III of the composite due to thickness. The addition of carbon fiber has been proven to improve the performance of composite ballistic at level II and reduce the formation of a fairness mode at level III. Composite samples succeeded in withstanding projectiles in ballistic tests with pistols and 9 mm projectiles, but failed in tests with rifles and 5.56 mm projectiles, with failure modes arising in the form of petaling, shear plugging, delamination, bulging, fiber breakage, and crack.

Abstrak :
Industri pertahanan nasional khususnya kendaraan tempur membutuhkan adanya pengembangan dari sisi material untuk meningkatkan efektivitas dalam menahan serangan proyektil serta mempermudah mobilitas saat digunakan di medan perang. Pada penelitian ini, digunakan komposit laminat dengan matriks berupa plat aluminium AA5052 dan serat kevlar dengan variasi jumlah lapisan sebanyak 20, 30, dan 40 layer. Kevlar di dalam komposit laminat ini diimpregnasikan dengan campuran nanopartikel SiC (Silikon Karbida) 50nm, ethanol, dan PEG-400 sebagai Shear Thickening Fluid (STF). Plat aluminium dan kevlar direkatkan menggunakan resin epoksi dan hardener dengan metode hand lay-up. Untuk mengetahui ketahanan balistik dan sifat mekanis, dilakukan pengujian balistik level III dan IV yang kemudian dianalisis kedalaman penetrasi proyektil dan diameter perforasi dari komposit laminat. Analisis mikrostruktur dan kandungan unsur dari komposit laminat dilakukan dengan Scanning Electron Microscopy (SEM), Energy Disperse X-Ray Spectrometry (EDS), dan Fourier Transfer Infrared Spectrometry (FTIR). Hasil penelitian menunjukkan adanya pengaruh pada ketahanan balistik dan kekuatan mekanis akibat pengimpregnasian nanopartikel SiC dan variasi jumlah kevlar yang digunakan pada komposit laminat. ......The national defense industry, especially combat vehicles, requires materials development to increase effectiveness in ballistic resistant and mobility when used on the battlefield. In this study, laminated composites with a matrix of AA5052 aluminum plate and kevlar fiber were used with variations in the number of layers of 20, 30, and 40 layers. The kevlar fabric in this laminated composite was impregnated with a mixture of 50nm SiC (Silicon Carbide) nanoparticles, ethanol, and polyethylene glycol (PEG-400) as Shear Thickening Fluid (STF). The aluminum and kevlar plates are glued together using epoxy resin and hardener by the hand lay-up method. To determine the ballistic resistance and mechanical properties, level III and IV ballistic tests were carried out followed by analyzing the projectile penetration depth and perforation diameter of the laminated composite. Analysis of the microstructure and elemental content of the laminated composites was carried out by Scanning Electron Microscopy (SEM), Energy Disperse X-Ray Spectrometry (EDS), and Fourier Transfer Infrared Spectrometry (FTIR). The results showed that there was an effect on ballistic resistance and mechanical strength due to the impregnation of SiC nanoparticles and variations in the amount of Kevlar used in laminated composites.

Abstrak :
This monograph covers all important issues of terminal ballistics in a comprehensive way combining experimental data, numerical simulations and analytical modeling. It uses a unique approach to numerical simulations as sensitivity measure for the major physical parameters. In the first chapter, the book includes necessary details about the experimental equipment which are used for ballistic tests. The second chapter covers essential features of the codes which are used in recent years all over the world, the Euler vs. Lagrange schemes, meshing techniques etc. The third chapter, devoted to the penetration mechanics of rigid rods, brings the update of modeling in this field. The fourth chapter deals with plate perforation and the fifth chapter deals with the penetration of shaped charge jets and eroding long rods. The last chapter includes several techniques for the disruption and defeating of the main threats in armor design. Throughout the book the authors demonstrate the advantages of the simulation approach in understanding the basis physics behind the investigated phenomena.