Hasil Pencarian  ::  Simpan CSV :: Kembali

"Composite Al A6061 / SiC can be made through methods Stir Casting, this method has been used widely because has middle cost and able to distribute the SiC particle well. This research use variation of SiC, from 2%, 5%, 8%, 10%, and 15%. To enhance the wettability between particle and matrix, Mg 10% was added to the molten aluminium. The result showed that the addition of 10% SiC is optimum among others, with tensile strength reach 247,8 Mpa, elongation 7,04846 % and hardness 54,333 HRB. This mechanical properties is better than the Al A6061 as cast. From datas above, it can be concluded that the more SiC being added, will improve the mechanical properties of material. However, if SiC pass the optimum value, the SiC tend to agglomerated and will deterioriate the mechanical properties of Al A6061/SiC. ;Composite Al A6061 / SiC can be made through methods Stir Casting, this method has been used widely because has middle cost and able to distribute the SiC particle well. This research use variation of SiC, from 2%, 5%, 8%, 10%, and 15%. To enhance the wettability between particle and matrix, Mg 10% was added to the molten aluminium. The result showed that the addition of 10% SiC is optimum among others, with tensile strength reach 247,8 Mpa, elongation 7,04846 % and hardness 54,333 HRB. This mechanical properties is better than the Al A6061 as cast. From datas above, it can be concluded that the more SiC being added, will improve the mechanical properties of material. However, if SiC pass the optimum value, the SiC tend to agglomerated and will deterioriate the mechanical properties of Al A6061/SiC. ;Composite Al A6061 / SiC can be made through methods Stir Casting, this method has been used widely because has middle cost and able to distribute the SiC particle well. This research use variation of SiC, from 2%, 5%, 8%, 10%, and 15%. To enhance the wettability between particle and matrix, Mg 10% was added to the molten aluminium. The result showed that the addition of 10% SiC is optimum among others, with tensile strength reach 247,8 Mpa, elongation 7,04846 % and hardness 54,333 HRB. This mechanical properties is better than the Al A6061 as cast. From datas above, it can be concluded that the more SiC being added, will improve the mechanical properties of material. However, if SiC pass the optimum value, the SiC tend to agglomerated and will deterioriate the mechanical properties of Al A6061/SiC. "

"ABSTRAKPenambahan partikel nano SiC kedalam matriks Al6061 menghasilkan material komposit dengan kekuatan mekanis yang tinggi namun tetap mampu mempertahankan sifat ulet. Magnesium sebesar 10% Vf juga ditambahkan sebagai agen pembasah agar didapatkan ikatan yang kuat pada daerah antarmuka. Pada penelitian ini digunakan variasi penambahan partikel nano SiC sebesar 0,05%, 0,10%, 0,15%, 0,20% dan 0,30% untuk mengetahui titik optimal penambahan penguat. Hasil dari penelitian ini menunjukkan penambahan partikel nano SiC optimal di komposisi 0,15%, dengan kekuatan tarik 263,43 MPa, presentase elongasi 7,67%, kekerasan 56,5 HRB, dan harga impak sebesar 0,0550 J/mm2. Peningkatan kekuatan mekanis pada komposit dihasilkan dari kehadiran fasa penguat Mg2Si, distribusi partikel nano SiC yang merata, serta pembasahan yang baik antara matriks dan partikel penguat.

---

ABSTRACTThe addition of nano SiC particles to Al6061 matrix has enhancing the mechanical properties of metal matrix composite while the ductility properties still maintained. 10% Vf of magnesium were used as wetting agent to achieve strong interface bonding. In the present work, Al6061 reinforced with various amounts (0,05%, 0,10%, 0,15%, 0,20% and 0,30%) of nano SiC were prepared. Results of this study shows the optimum content of nano SiC in Al6061 matrix were 0,15% Vf, with UTS (Ultimate Tensile Strength) reached 263,43 MPa, 7,67% elongation, hardness up to 56,5 HRB, and 0,0550 J/mm2 impact value. The enhancement of mechanical properties of Al6061/SiC composite were influenced by the presence of Mg2Si phase, good distribution of nano SiC particles, and also good interface bonding between matrix and reinforce.;"

"[Komposit paduan aluminium A356 berpenguat silikon karbida memiliki potensi untuk memiliki sifat mekanik yang baik dengan massa yang rendah. Pada penelitian ini, pengecoran dilakukan melalui metode pengecoran aduk dengan menambahakan silikon karbida dengan presentase 2%, 5%, 8%, 10% dan 15% fraksi volume ke dalam matriks, serta penambahan magnesium 10% fraksi berat sebegai agen pembasahan. Hasil penelitian menunjukkan peningkatan kekuatan tarik mencapai nilai optimum pada penambahan 8%. Selain itu, sifat kekerasan meningkat seiring dengan penambahan partikel penguat yang juga menyebabkan turunnya laju keausan. Karakterisasi struktur mikro menunjukkan terbentuknya huruf cina serta Mg2Si utama dan eutektik.

---

Aluminium alloy A356 composite strengthened by silicon carbide particles has the potential to have good mechanical properties with low mass. In this study, casting was done by stir casting method by added silicon carbide 2%, 5%, 8%, 10% dan 15% volume fraction, also magnesium 10% weight fraction as a wetting agent. The results showed that the increase in tensile strength reach optimum point on the 8%. In addition, the nature of hardness increased with the addition of silicon carbide which also cause a decrease in the wear rate. Microstructure characterization showed the presence of chineese script, primary and eutectic Mg2Si.

, Aluminium alloy A356 composite strengthened by silicon carbide particles has the potential to have good mechanical properties with low mass. In this study, casting was done by stir casting method by added silicon carbide 2%, 5%, 8%, 10% dan 15% volume fraction, also magnesium 10% weight fraction as a wetting agent. The results showed that the increase in tensile strength reach optimum point on the 8%. In addition, the nature of hardness increased with the addition of silicon carbide which also cause a decrease in the wear rate. Microstructure characterization showed the presence of chineese script, primary and eutectic Mg2Si.

]"

"[ABSTRAKKomposit nano Al A356 berpenguat partikel Al2O 3 berpotensi untuk meningkatkan kekuatan sifat mekanis tanpa mengorbankan keuletan pada matriks. Pada penelitian ini dilakukan variasi penambahan fraksi volume dari partikel nano Al2O 3 sebesar yaitu 0.1%, 0.2%, 0.5%, 1%, dan 1,2%. Untuk meningkatkan kemampubasahan dari Al2O 3 pada Al A356 ditambahakn Mg sebesar 10%. Hasil penelitian menunjukkan bahwa komposit Al A356/Al2O 3 dengan 0.5% Vf memiliki sifat mekanis yang lebih baik daripada yang lain. Nilai kekuatan tariknya mencapai 140,3 MPa lalu elongasinya sebesar 9,563% dan kekerasannya mencapai 46,2 HRB. Akan tetapi nilai mekanis dari kekuatan tarik masih dibawah dari Al A356 As cast maupun Al 356. Fenomena ini disebabkan karena adanya porositas dan persebaran partikel nano yang tidak merata.ABSTRACTAluminium A356 nano composite reinforced with Al2O 3 particle have a potential to increase mechanical properties while maintaining good ductility. In this study, the addition %Vt variation of Al2O 3. Variation used is 0.1%, 0.2%, 0.5%, 1%, dan 1,2%. To improve wettability of Al2O 3 in Al A356 addes 10% Mg. The results showed that the composite Al A356 / SiC 0,5% Vf have better mechanical properties than others. The ultimate tensile strength reach 140.3 MPa with 9.56% elongation. Hardness value reach 46,2.1 HRB. However, the value of ultimate tensile strength is still below the mechanical Al A356 As cast and Al 356. This phenomenon is due to the porosity and bad particle dispersion.;Aluminium A356 nano composite reinforced with Al2O 3 particle have a potential to increase mechanical properties while maintaining good ductility. In this study, the addition %Vt variation of Al2O 3. Variation used is 0.1%, 0.2%, 0.5%, 1%, dan 1,2%. To improve wettability of Al2O 3 in Al A356 addes 10% Mg. The results showed that the composite Al A356 / SiC 0,5% Vf have better mechanical properties than others. The ultimate tensile strength reach 140.3 MPa with 9.56% elongation. Hardness value reach 46,2.1 HRB. However, the value of ultimate tensile strength is still below the mechanical Al A356 As cast and Al 356. This phenomenon is due to the porosity and bad particle dispersion.;Aluminium A356 nano composite reinforced with Al2O 3 particle have a potential to increase mechanical properties while maintaining good ductility. In this study, the addition %Vt variation of Al2O 3. Variation used is 0.1%, 0.2%, 0.5%, 1%, dan 1,2%. To improve wettability of Al2O 3 in Al A356 addes 10% Mg. The results showed that the composite Al A356 / SiC 0,5% Vf have better mechanical properties than others. The ultimate tensile strength reach 140.3 MPa with 9.56% elongation. Hardness value reach 46,2.1 HRB. However, the value of ultimate tensile strength is still below the mechanical Al A356 As cast and Al 356. This phenomenon is due to the porosity and bad particle dispersion., Aluminium A356 nano composite reinforced with Al2O 3 particle have a potential to increase mechanical properties while maintaining good ductility. In this study, the addition %Vt variation of Al2O 3. Variation used is 0.1%, 0.2%, 0.5%, 1%, dan 1,2%. To improve wettability of Al2O 3 in Al A356 addes 10% Mg. The results showed that the composite Al A356 / SiC 0,5% Vf have better mechanical properties than others. The ultimate tensile strength reach 140.3 MPa with 9.56% elongation. Hardness value reach 46,2.1 HRB. However, the value of ultimate tensile strength is still below the mechanical Al A356 As cast and Al 356. This phenomenon is due to the porosity and bad particle dispersion.]"

"Metode fabrikasi material komposit paduan Al 6061 dengan penambahan partikel mikro SiC dipilih menggunakan metode pengecoran aduk karena mampu mendistribusikan partikel penguat SiC dan memiliki nilai ekonomis yang baik. Material ini kemudian diharapkan memiliki sifat mekanis yang baik dengan densitas yang relatif rendah.Pada penelitian ini dilakukan variasi penambahan volume fraksi dari partikel miro SiC sebesar 2%, 4%, 6%, 8%, dan 10% untuk mengetahui nilai optimal dari penambahan partikel penguat. Penambahan Mg sebesar 10 wt.% dilakukan untuk meningkatkan kemampubasahan dan penambahan Sr dan TiB dilakukan untuk meningkatkan sifat mekanis dari material komposit. Kemudian didapatkan nilai kekuatan tarik, elongasi, dan kekerasan memiliki nilai maksimal pada penambahan partikel penguat SiC sebesar 10 wt.% dengan nilai masing-masing 230 MPa, 6,5%, dan 62,2 HRB. Sedangkan nilai kekuatan impak memiliki nilai optimum pada penambahan partikel penguat sebesar 4% dengan nilai 0.0294 Joule/mm2. Kemudian juga didapatkan bahwa persentase porositas terus meningkat seiring dengan peningkatan volume fraksi dari partikel penguat.

---

Manufacturing of composite material Aluminum Alloy (Al-Mg-Si) with the addition of micro SiC particles reinforcement chosen using stir casting method because it can be able to evenly distribute the SiC particles reinforcement and has a good economic value. Then this addition of SiC particles predicted will improved the mechanical properties and density of the materials.

In this study, the addition of micro particles volume fraction in the amount of SiC 2%, 4%, 6%, 8%, and 10% were used in order to know the optimum volume fraction. The addition of Mg 10 wt.% were used as wetting agent to increase the wettability between matrix and reinforce and the addition of AlSr and TiB were used to increase the mechanical properties. As a result, the ultimate tensile strength, elongation, and hardness value has a maximum value in addition of micro particles volume fraction in the amount of SiC 10 wt.%with the value up to 230 MPa, 6,5%, dan 62,2 HRB. However, the impact value and hardness value has a optimum value in addition of micro particles volume fraction in the amoung of SiC 4% with the value 0.0294 Joule/mm2. The percentages of porosity were increased along with the increase of micro particles volume fraction."

"ABSTRAKPenambahan partikel penghalus butir Ti-B dalam matriks ADC12 berpenguat nano SiC mampu meningkatkan sifat mekanis komposit dengan mekanisme penghalusan butir. Ti-B ditambahkan dengan tujuan menghasilkan Al3Ti sebagai nuklean dan memodifikasi struktur dendritik menjadi globular. Penambahan magnesium sebesar 10 bertujuan sebagai agen pembasah agar didapatkan ikatan antarfasa antara matriks dan penguat partikel nano SiC. Pada penelitian ini ditambahkan 0.15 Vf nano SiC dan variasi penambahan Ti-B 0.0 , 0.02 , 0.04 , 0.06 , dan 0.08 wt . Hasil penelitian dikarakterisasi secara komposisi dengan OES dan XRD, mikrostruktur dengan OM dan SEM, kemudian diuji mekanis tarik, keras, aus, dan impak. Komposisi paling optimal yaitu pada penambahan 0.04 wt TiB, yang menghasilkan nilai kekuatan tarik 135.9 MPa, kekerasan 45.6 HRB, laju aus 1.47x10-5 mm3/s, dan harga impak 0.0225 J/mm2. Peningkatan penambahan Ti-B linear dengan reduksi ukuran butir, namun penambahan lebih dari 0,04 wt tidak menunjukkan perubahan ukuran butir secara signifikan. Selain karena penghalusan butir akibat Al3Ti, peningkatan kekuatan mekanis terjadi akibat terbentuknya fasa MgAl2O4 pada antarmuka partikel nano SiC dan matriks ADC12.

---

ABSTRACTAddition of Ti B grain refiner in ADC12 nano SiC composite results in improvement of mechanical properties through grain refinement mechanism. Ti B was added to form Al3Ti as nucleant and modify the dendritic structure into globular. 10 of Mg added as a wetting agent to improve wettability between nano SiC as reinforce and ADC12 as matrix to maintain a good interphase. In this study, used 0.15 vf of nano SiC and few variations of TiB respectively 0.0 , 0.02 , 0.04 , 0.06 , dan 0.08 wt . Several test were conducted to characterize the material OES, XRD, OM, SEM, and destructive test tensile, hardness, wear, and impact . Obtained the best composition is 0.04 wt TiB which results 135,9 MPa in Ultimate Tensile Strength UTS , 45.6 HRB in hardness, 1.47x10 5 mm3 s as wear rate, impact strength 0.0225 J mm2. The increase of Ti B addition results in grain refinement but the addition more than 0,04 wt gives no significant results. The increase in mechanical properties of composites mainly because of Al3Ti acts as nucleant which initiates the grain refinement and the existence of MgAl2O4 phase which indicates a good interphase between nano SiC and ADC12 matrix."

"Piston pada motor adalah komponen dari mesin pembakaran dalam yang berfungsi sebagai penekan udara masuk dan penerima hentakan pembakaran pada ruang bakar cylinder liner. Material penyusun piston tersebut adalah aluminium AC8H yang sifatnya ringan, kuat, dan tahan aus. Dalam proses pengecoran paduan aluminium, penambahan modifier dan perlakuan panas merupakan proses yang dapat mempengaruhi sifat mekanis coran paduan. Sifat mekanis yang dimaksud adalah kekerasan, kekuatan tarik, keuletan serta keausan.Penelitian ini bertujuan untuk mengetahui kemungkinan penggantian proses perlakuan panas T6 (artificial ageing) yang merupakan standar dari proses pembuatan piston dengan proses penambahan modifier dan kemungkinan mempersingkat proses perlakuan T6 (artificial ageing) dengan proses T4 (natural ageing). Penelitian dilakukan dengan melebur ingot AC8H yang kemudian ditambahkan modifier stronsium dalam ladle. Jumlah kandungan stronsium yang dihasilkan setelah proses penambahan modifier adalah sebesar 0,00072% Sr, 0,0068% Sr, 0,0133% Sr dan 0,031% Sr. Hal yang sama dilakukan dengan menambahkan modifier phospor, dimana kandungan phospor yang dihasilkan menjadi 0,0036% P,0,0038% P, 0,0041% P dan 0,0046% P. Pada perlakuan panas setelah proses pengecoran, hasil ascast dilakukan proses T6 (artificial ageing) dan T4 (natural ageing) dengan pengamatan 0 jam, 24 jam, 48 jam , 72 jam, 96 jam dan 120 jam. Masing masing sampel hasil percobaan diatas dilakukan pengujian karakterisasi struktur mikro dan sifat mekanis.Hasil pengujian menunjukkan bahwa penambahan 0,031 % Sr dan Proses perlakuan panas T4 (natural ageing) 96 jam dan 120 jam setelah quenching memiliki sifat mekanis yang telah masuk range standar kualifikasi komponen piston. Dalam implementasi hasil ini masih harus dilanjutkan dengan uji coba melalui proses engine dyno test.

---

Piston is motor components of the engine which works as a press incoming air and recipient burning fuel in the cylinder liner space. Material of aluminum piston is AC8H that are lightweight, strong, and wear resist. In the process of casting aluminum alloy, adding modifiers and heat treatment is a process that can affect the mechanical properties as cast alloy. Mechanical properties of the object is referred to hardness, tensile strength, elongation and wear resistance.This research aims to find out the possibility of replacing the T6 heat treatment process (artificial ageing), as standard process of making a piston with the addition of modifiers and possibility to shorten the treatment T6 (artificial ageing) with the T4 (natural ageing). Research conducted by melt ingot AC8H then added Strontium in ladle. Strontium added that the amount until contain 0.00072% Sr, 0.0068% Sr, 0.0133% Sr, and 0.031% Sr. The same is done by adding Phospor until contain 0,0036% P, 0.0038% P, 0.0041% P and 0.0046% P. In the heat treatment process sample after casting will be process with T6 and T4 observation 0 hour, 24 hours, 48 hours, 72 hours, 96 hours and 120 hours. Each sample of an experiment conducted over the microstructure characterization and mechanical properties test.The test results indicate that the addition of 0.031% Sr. and heat treatment process T4 (natural ageing) 96 hours and 120 hours after quench as mechanical properties have already entered the qualifying standard range of part-piston. Implementation of the experiment must be continued to engine dyno test process before mass production."

"Aluminium adalah material yang banyak digunakan dalam industri otomotif karena sifatnya yang ringan, kuat dan tahan korosif. Salah satu penggunaanya untuk komponen cylinder head, komponen ini menggunakan jenis paduan aluminium AC4B dengan proses low pressure die casting. Namun produk yang dihasilkan dalam proses pengecoran ini banyak ditemukan kegagalan seperti porositas, penyusutan (shrinkage) yang menyebabkan kebocoran.Dari permasalahan tersebut maka dilakukan penelitian yaitu dengan penambahan titanium kedalam aluminium AC4B yang bertujuan untuk menigkatkan sifat mekanis dan meminimalisasi kegagalan pada komponen cylinder head yang dihasilkan. Penelitian ini secara khusus ditujukan untuk mempelajari pengaruh variasi persentase titanium (0.019 wt % dan 0.029 wt %) terhadap penghalusan butir aluminium AC4B dengan proses low pressure die casting. Kemudian menguji sampel cylinder head dengan uji tarik, uji kekerasan, pengukuran besar dendrite arms spacing dan menganalisa mikrostuktur dengan mikroskop optik dan dengan SEM dan EDS, serta pengujian bocor.\Penambahan penghalus butir sebesar 0.019 wt % Ti dan 0.029 wt % Ti pada aluminium AC4B meningkatkan kekuatan tarik sebesar 13.4 % dan 20.1 % dengan bentuk perpatahan getas. Sementara, nilai kekerasan juga mengalami peningkatan dengan panambahan titanium. Pada bagian tipis, penambahan 0.019 wt % Ti dan 0.029 wt % Ti meningkatkan nilai kekerasan sebesar 3.06 % dan 5.65 %. Pada bagian tebal, penambahan 0.019 wt % Ti dan 0.029 wt % Ti meningkatkan nilai kekerasan sebesar 2.14 % dan 5.19 %. Untuk besar dendrite arms spacing terjadi penurunan dengan penambahan titanium. Pada bagian tipis, panambahan 0.019 wt % Ti dan 0.029 wt % Ti menurunkan besar DAS sebesar 29.3 % dan 48.5 %. Pada bagian tebal, dengan penambahan 0.019 wt % Ti dan 0.029 wt % Ti menurunkan besar DAS sebesar 6.67 % dan 28.6 %. Pada pengamatan mikrostruktur menggunkan SEM tidak ditemukannya fasa Al3Ti. Untuk hasil uji bocor terdapat cylinder head yang mengalami bocor. Penambahan 0.019 wt % Ti dan 0.029 wt % Ti tidak terlalu efektif untuk mengurangi kegagalan shrinkage dan bocor pada komponen cylinder head tapi dapat mengurangi kegagalan karena blow hole.

---

Aluminum is the material most used in automotive industry because of light, good strength and corrosion resistant. One of the application of aluminum is used for cylinder head component, this component use aluminum alloy AC4B with low pressure die casting process. But the product in casting process much have failure such as porosity and shrinkage which cause leakage.This experiment was conducted to counter these problems with addition of titanium to increase mechanical properties and minimize reject from cylinder head manufacturing. The subject of this research was to study the effect of 0.019 wt. % and 0.029 wt. % titanium addition on grain refinement of AC4B alloy produced with low pressure die casting. Cylinder head samples were tested with tensile test, hardness test, dendrite arms spacing observation. Microstructure analysis was performed with optical microstructure and SEM/EDS, and also leakage test.Grain refiner addition of 0.019 wt. % Ti and 0.029 wt. % Ti increased tensile strength 13.4 % and 20.1 % with brittle fracture. Meanwhile, hardness value also increased with the addition of titanium. On thin parts, addition of 0.019 wt % Ti and 0.029 wt % Ti increased hardness value for 3.06 % and 5.65 %. On thick parts, the addition of 0.019 wt % Ti and 0.029 wt % Ti increased hardness value for 2.14 % and 5.19 %. The addition of titanium decreased dendrite arms spacing value. On thin parts, the addition of 0.019 wt % Ti and 0.029 wt % Ti decreased DAS value for 29.3 % and 48.5 %. On thick parts, the addition of 0.019 wt % Ti and 0.029 wt % Ti decreased DAS value for 6.67 % and 28.6 %. Al3Ti was not found with microstructure analysis using SEM. On leakage test, there were some cylinder head that exhibit leakage. On 0.019 wt % Ti there were 5 cylinder head that experience leakage, or 6.25 % and on 0.029 wt % Ti addition there were 8 cylinder head that experience leakage, or 10 %.On leakage test, there are several cylinder head that exhibit shrinkage. The addition of 0.019 wt % Ti and 0.029 wt % Ti were not very effective in decreasing shrinkage failure and leakage on cylinder head component, but effective in decreasing failure caused by blow hole."

"Pembuatan material komposit dengan matriks Aluminium 6061 (Al-Mg-Si) dengan penambahan partikel Al2O3 sebagai penguat dan juga penambahan Stronsium sebesar 0,02% sebagai modifier dan penambahan TiB sebesar 0,03% sebagai grain Refiner dan juga penambahan Mg sebesar 10% digunakan metode pengecoran aduk karena mudah dilakukan dan juga ekonomis. Penambahan Al2O3 sebagai penguat dapat meningkatkan sifat mekanis dari komposit. Pada penelitian ini, variasi penambahan volume fraksi dari Al2O3 sebesar 2%, 4%, 6%, 8%, dan 10% untuk mengetahui nilai optimum penambahan penguat Al2O3 terhadap sifat mekanis dari komposit Al/Al2O3.Hasil yang didapatkan dari pengujian ini, menunjukkan bahwa penambahan partikel penguat Al2O3 sebesar 6 wt.% memiliki nilai kekuatan tarik dan elongasi yang paling tinggi dengan nilai mencapai 22,4 MPa dengan %elongasi sebesar 7%. Lalu pada nilai kekerasan dan harga impak, penambahan volume fraksi Al2O3 sebesar 10 wt.% memiliki nilai kekerasan paling tinggi mencapai 54,98 HRB dan untuk harga impak mencapai nilai tertinggi dengan harga impak sebesar 0,0275 J/mm2. Penambahan volume fraksi alumina dapat meningkatkan %porositas yang terbentuk pada material komposit.

---

The making of composite material with aluminum 6061 (Al-Mg-Si) as matrix with the addition of Al2O3 particulate as reinforcement and also with the addition of strontium 0,02% as modifier and addition of TiB 0,03% as grain refiner and addition of Mg 10% as wetting agent using stir casting method because its easy and economist. The addition of Al2O3 as reinforcement can improved the mechanical properties of the composite. In this study, addition of volume fraction of Al2O3 variated by 2%, 4%, 6%, 8%, and 10% to know the optimum addition of particulate Al2O3 as reinforcement to the mechanical properties of composite Al/Al2O3.

The results show that addition of 6wt% reinforcement particulate Al2O3 has highest UTS with value 22,4MPa and the %elongation reach to 7%. Then on hardness value and impact value, 10wt% addition of particulate Al2O3 has the highest hardness value reach to 54,98 HRB and for impact value reach to 0,0275 J/mm2. And the addition of alumina can cause the increasing of %porosity formed in the composite material."

"Dengan kekuatan yang dimiliki aluminium namun dengan berat yang lebih ringan dibanding baja membuat perkembangan yang menjanjikan dalam dunia industri. Penelitian ini bertujuan untuk mengembangkan material komposit logam bermatriks ADC 12. Oleh karena itu, ADC 12 sebagai aluminium dengan paduan utama Silikon dan Tembaga, memiliki beberapa sifat mekanis yang akan dikembangkan dengan penambahan partikel penguat berupa Al2O3 dengan variasi penambahan 0,50; 0,10; 0,15; 0,20; 0,30 Vf. melalui pengecoran aduk. Penambahan partikel penguat yang berukuran nano akan meningkatkan kekuatan tarik sebesar 56,74 , kekerasan sebesar 42,99 , dan ketahanan ausnya sebesar 30,92 serta menurunkan harga impaknya. Penambahan Al-5Ti-1B ditambahkan sebagai penghalus butir dan Sr sebagai agen pemodifikasi, untuk meningkatkan sifat mekanik. Magnesium ditambahkan sebesar 5 berat sebagai agen pembasahan antara matriks dan logam. Dengan melakukan karakterisasi sampel seperti pengujian metalografi, SEM-EDS, dan XRD akan dilihat bahwa terbentuk fasa-fasa yang akan mempengaruhi sifat mekanis material.

---

Aluminum has been recently promising developing in various industry including transportation due to its strength and lower weight ratio compared to steel. This research is aiming to develop Metal Matrix Composite MMC using ADC 12. Furthermore, Aluminum ADC 12 with major constituent of silicon and copper is improved by means of mechanical properties by adding nano Al2O3 with variation of 0.50, 0.10, 0.15, 0.20, 0.30 Vf through stir casting method. Nano sized alumina later found to increase tensile strength about 56,74 , hardness about 42,99 , and wear resistance about 30,92 , yet decreasing the impact strength. Al 5Ti 1B was added to the alloy as grain refiner while Sr was added to modifies Si structure. Both were added to improve mechanical properties. Magnesium is presented at 5 wt to enhance its wettability. Furthermore, material is characterised under several testing such as metallography, SEM EDS, and XRD to confirm any formed phase that correspond to its mechanical properties."