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Abstrak :
Kebutuhan material dengan sifat mekanik yang baik serta berbobot ringan sudah semakin tinggi saat ini, terutama untuk aplikasi yang memerlukan performa tinggi. Komposit aluminium berpenguat Al2O3 (AMC) menawarkan keunggulan tersebut. Pada penelitian ini, fabrikasi komposit dilakukan menggunakan paduan aluminium 6061 dan penguat serbuk Al2O3 berukuran 60 μm. melalui proses stir casting. Dalam penelitian ini diketahui pengaruh penambahan kadar Al2O3 serta Mg sebagai agen pembasahan terhadap sifat mekanik komposit. Variasi kadar Al2O3 yang ditambahkan sebesar 10% dan 15% fraksi volume serta kadar Mg 8%, 10%, dan 15%. Hasil penelitian menunjukan bahwa kekuatan tarik optimal sebesar 170 Mpa diperolah pada komposit dengan kadar Al2O3 10% dan Mg 10%. Di mana kekerasan dan ketahanan aus komposit meningkat seiring penambahan kadar Al2O3 dan Mg. Demikian halnya porositas meningkat ketikat kadar Al2O3 yang ditambahkan semakin besar.

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Demand of materials with good mechanical properties and have lightweight increased in recent years especially for high performance applications. Aluminium reinforced Al2O3 composite (AMC) provide this superiority. In this research, composite was fabricated from Aluminium Alloy 6061 and 60 μm Al2O3 reinforce particles by stir casting process. This research investigated the effect of addition Al2O3 content and Mg as wetting agent to mechanical properties of composite. The addition of Al2O3 into Al melt was 10% and 15% of volume fraction and Mg was 8%, 10%, and 15%. The result showed that the optimum tensile strength of 202 Mpa was obtained in composite with 10% volume fraction of Al2O3 and 10% Mg. Moreover, hardness and wear resistant of composite increased with the addition of Al2O3 and Mg content. Porosity also increased when greater amount of Al2O3 content was added.

Abstrak :
Kebutuhan akan material yang memiliki sifat mekanik yang baik serta berbobot ringan sudah semakin tinggi saat ini, terutama untuk aplikasi yang memerlukan performa tinggi. Komposit aluminium berpenguat Al2O3 (AMC) menawarkan keunggulan tersebut. Pada penelitian ini, fabrikasi komposit dilakukan menggunakan paduan aluminium 6061 dan penguat serbuk Al2O3 berukuran 60μm melalui proses stir casting. Dalam penelitian ini diketahui pengaruh penambahan kadar Al2O3 serta Mg sebagai agen pembasahan terhadap sifat mekanik komposit. Variasi kadar Al2O3 yang ditambahkan sebesar 10% dan 15% fraksi volume serta kadar Mg 8%, 10%, dan 15%. Hasil penelitian menunjukkan bahwa kekuatan tarik optimal sebesar 202 MPa diperoleh pada komposit dengan kadar Al2O3 10% dan Mg 10%. Selain itu, kekerasan dan ketahanan aus komposit meningkat seiring penambahan kadar Al2O3 dan Mg. Porositas juga meningkat ketika kadar Al2O3 yang ditambahkan semakin besar.

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Demand of materials with good mechanical properties and have light weight increased in recent years especially for high performance applications. Aluminium reinforced Al2O3 composite (AMC) provide this superiority. In this research, composite was fabricated from Aluminium Alloy 6061 and 60 μm Al2O3 reinforce particles by stir casting process. This research investigated the effect of addition Al2O3 content and Mg as wetting agent to mechanical properties of composite. The addition of Al2O3 into Al melt was 10% and 15% of volume fraction and Mg was 8%, 10%, and 15%. The result showed that the optimum tensile strength of 202 MPa was obtained in composite with 10% volume fraction of Al2O3 and 10% Mg. Moreover, hardness and wear resistant of composite increased with the addition of Al2O3 and Mg content. Porosity also increased when greater amount of Al2O3 content was added.

Abstrak :
Aluminium dapat dijadikan sebagai matriks pada suatu komposit sehingga sifat mekanisnya meningkat. Komposit aluminium matriks berpenguat kawat tali baja karbon tinggi diharapkan dapat meningkatkan kekuatan komposit untuk aplikasi armor. Penambahan Cu dan proses canai dingin diharapkan dapat meningkatkan kekerasan material dan diharapkan mempengaruhi sifat antarmukanya. Penelitian ini membuat material komposit matriks Aluminium (Al-7Si) dengan penguat kawat tali baja dengan metode Squeeze casting. Cetakan yang digunakan didalamnya disusun kawat berdiameter 1 mm dengan jarak antar kawat 2-3 mm dalam arah yang sama dan dilakukan preheating hingga 350 0C. Matriks aluminium dalam bentuk Al-7Si dilebur dan dilakukan variasi penambahan 1,92%; 2,14%; and 3,75% Cu. Kemudian dituang ke dalam cetakan pada temperatur 850 0C dan dilanjutkan proses squeeze dengan pemberian tekanan sebesar 10 barr. Setiap sampel dengan variasi komposisi dibagi menjadi dua, salah satu bagian dilakukan proses canai dingin dengan reduksi sebesar 10 %. Semua sampel dilakukan pengamatan pada daerah antarmuka dengan menggunakan mikroskop optik dan dilakukan pengujian kekerasan untuk melihat pengaruh penambahan Cu dan proses canai dingin terhadap sifat antarmuka dan kekerasannya. Juga mengamati pengaruh jarak antar kawat terhadap sifat antarmuka. Hasil pengujian menunjukkan bahwa sifat antarmuka komposit menjadi buruk seiring penambahan unsur Cu ke dalam matriks paduan aluminium. berdasarkan pengamatan fotomikro, dimana keberadaan void disekeliling kawat bertambah seiring penambahan Cu. Pengaruh dari proses canai dingin terhadap kekerasan, menaikkan kekerasan dibanding dengan sampel tanpa dilakukan proses canai. Pengaruh proses canai dingin memperkecil daerah void dan porositas terhadap sifat antarmuka. Jarak antar kawat yang masih memungkinkan terjadinya void didapat sebesar 0,5 mm.

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Aluminium that used as matrix of composites, has improve its mechanical properties. Aluminium matrix composites with reinforced high carbon steel wires so the composites will have strength properties for armor application. The addition of Cu and cold roll process can effect to increase hardness and also effect the interface condition of the composites. In the experiment, fabrication composites aluminium matrix with reinforced steel wires by Squeeze casting. Mould used the 1 mm diameter high carbon steel wires and the distance between wires is 2-3 mm that arranged in unidirectional and dies is being preheat to 350 0C. Matrix Al-7Si is being melted and add with 1,92%; 2,14%; and 3,75% Cu before pouring at 850 0C. After the melting aluminium has been poured to the dies, give directly 10 barr pressure. Each specimens with the variation of Cu alloying is cut into two pieces, with one of the pieces is process by 10 % reduction cold roll. All specimens is observed using the optical microcope and tested with Rockwell hardness Tester to see the hardness oof specimens. Also, to observed the effect of distance between wires to the interface condition. The result of this experiment shows that the interface of composite become poor as well as the increasing of percent Cu. It is based on the observation of the interface area photograph using by optical microscope, that the void presents which become the indication of bad interface condition, more voids for the increasing percent Cu. Cold roll process has increased the hardness of composite. Compare to the specimen without cold rolled, the specimen with cold rolled has average higher hardness. Also, The effect of cold roll seem less voids area and porosity. The distance between wires which could produce void that can be observed from this experiment is 0,5 mm.