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Abstrak :
Komposit matriks atau MMC's menawarkan masa depan yg baik,spesifik kekakuan (stiffnes) dan kekuatan meningkat relatif terhadap bhn tanpa penguatan walaupun sifat meakanik dpt dipengaruhi oleh kehadiran porositas dr prosesi pengecoran dengan stiring.Pengaruh dr penekanan isostatik panas (HIPping) pd porositas didlm paduan aluminium stir-cast A357/15 vol%Sic partikel MMC's telah diteliti.Empat perlakuan HIPping yg berbeda telah diselidiki dan hasilnya menunjukkan bahwa HIPping dengan kondisi 565oC/103 MPa/15 menit diikuti oleh 535oC/103MPa/2 jam adalah yg optimum.Pengujian 4 titik banding dengan takik tunggal dilakukan pd benda uji yg telah mengalami HIPping. Kekuatan bending telah meningkat secara signifcan krn berkurangnya porositas setelah kondisi HIPping ini di bandingkan bhn bakunya.Partikel penguat keramik yg dikombinasikan dengan paduan aluminium matrix composit dpt menyediakan kebutuhan antara penghematan berat(pengurangan berat) dan ketangguhan yg diperlukan.

Abstrak :
Pembuatan komposit matriks logam Al-SiC dapat dilakukan dengan metode infiltrasi tanpa tekanan (PRIMEX). Penelitian ini dilakukan dengan menggunakan ingot alumunium AC2B sebagai matrik dan 50%Vf serbuk SiC sebagai penguat yang dicampur dengan 10%wt Mg sebagai wetting agent. Waktu tahan dan suhu pemanasan pada penelitian ini divariasikan untuk melihat pengaruh waktu tahan dan suhu pemanasan terhadap sifat mekanik dari komposit Al-SiC. Waktu tahan yang digunakan adalah 2, 5, 8, 10, dan 12 jam sedangkan suhu pemanasan yang digunakan 750, 800, 900, 1000, dan 1100°C. Komposit yang diperoleh dianalisa baik sifat mekanis seperti densitas, porosital, kekerasan, laju aus dan metalography. Lamanya waktu tahan dan meningkatnya suhu pemanasan menghasilkan sifat mekanis yang lebih baik dari komposit logam Al/SiC tersebut, dan ditemukan bahwa kondisi optimum untuk mendapatkan sifat mekanis yang baik adalah pada kondisi waktu tahan 10 jam dan suhu pemanasan 1000°C.

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Effect of Firing Temperature and Holding Time on Characterization of Al/SiC Metal Matrix Composites Produced by Pressureless Infiltration. The production of Al-SiC metal matrix composite can be carried out by pressureless metal infiltration processs (PRIMEX). The experiment was conducted using aluminium AC2B ingot as a matrix and 50%Vf SiC powder as a reinforcement which is mixed with 10% Mg powder for wetting agent. The variables of this experiment are holding time and firing temperature to investigate the effect of these conditions on mechanical properties of Al-SiC metal matrix composites. Holding time was conducted for 2,5,8,10,12 hours and firing temperatures was 750, 800, 900, 1000, 1100°C respectively.. The composites produced are analysed both mechanical properties and metalography such as densities, porosities, hardness, as well as wear rate. The results showed that the longer holding time and increasing firing temperature will increase mechanical properties of Al-SiC metal matrix composites, and it is found that the optimum mechanical properties at 1000°C for 10 hour.

Abstrak :
Aluminum, as a conductor material, has long been used for high-voltage overhead transmission lines due to its economic value and high electrical conductivity. By adding Al2O3np and alloying elements such as zirconium (Zr), cerium (Ce), and magnesium (Mg), aluminum’s strength and performance could be improved without compromising too much of its electrical conductivity. The focus of this research was to investigate the mechanical, electrical properties, and microstructure of Al-0.12%Zr-0.15%Ce-5%Mg, reinforced with different volume fractions (from 0.5 to 1.5%) of Al2O3 nano particles, using the stir casting method. The tensile strength of the composite was improved by up to 1.2 vf-% in alumina, and decreased with further addition due to clustering and pores, while elongation was reduced with when increasing the reinforcement. It was found that the electrical conductivity of the composite generally decreased with the addition of reinforcement. The microstructure observations showed that the composites yielded finer grains and more pores than the unreinforced alloy, with 1.2vf-% of reinforcement having the finest grain. The electrical conductivity of the composite was 44% IACS, which is still lower than that of the unreinforced alloy.

Abstrak :
Metal Matrix Composite (MMCs) is combination from two material or more with metal as matrix developed to improve the nature of metal; strength, hardness. electric resistance stability at high temperature. Aluminum as a matrix composite developed because is light, cheap, and easy to fabrication. Pressureless infiltration is one of the fabrication process of metal matrix composite in a melt condition which is developing because more economic; no need complicated equipments. Characteristic of metal matrix: composite can be influenced by infiltration temperature, dopant content (Magnesium), % Vf reinforcement and holding time. This research aim is to study the effect of temperature infiltration, as well as magnesium content on characterization of A£fA1,O, metal matrix composite i.e, thermal expansion, hardness, wear resistance, porosity and density as well as metallography. The infiltration temperature used various from 800 to 1200°C and Al;03 particle reinforcement was 5U%Fj= The magnesium content was also various from 4% to l2% wt and holding time was I0 hours. The results shows that higher magnesium content produced more Al molten infiltrated into ,41,O,~ preform. It is found that the optimum performance of composite produced at 1100° C.

Abstrak :
This research is to study the effects of _firing temperature and holding time on characteristics of Directed Metal Oxidation (DIMOAQ Ceramic Matrix Composites (CMCs) SiC /' A1 product. In this research, the firing temperature and holding time used are varied from 900° C to 1300° C with holding time 10 and 20 hours for each temperature. The characterizations of composite products are examined such as density and porosity test, micro hardness test, microstructure examination and chemical composition test. The results show that SiC preform has been infiltrated by Al liquid at tiring temperature of 1100"C for 20 hours. Composite product with the highest density (3,54 gram / cm3) can be obtained at firing temperature of 1100°C for 20 hours. Porosity tents to increase with increasing firing temperature. Composite product with highest micro hardness (1820 VHM can be obtained at firing temperature of 1300°C for 10 hours. At the some firing temperature, composite at products micro hardness for 20 hours tower than composite product with holding time I0 hours. Distribution of SiC particles spread over quite uniform on SiC/A1 composites product. Around SiC particles can be found Al, spinel (MgAl2O2). Al2O2, and possibility Mg,Si.

Abstrak :
Pure Al/SiC metal matrix composites (MMC) have been successful produced by the Lanxide process with different processing temperature for 8 hours. The process is simply without aid externally pressure. However, N2 oxygen free was flushed during the process. Molten pure Al has fully infiltrated to the preform with Sl/1% Mg at 750, 800, 850, 900 and 1000°C§ but infiltration did not occur to the preform with 3Vj'% Mg. Voids exist above the infiltrated preform in the systems with higher temperature (900 °C and 1000°C) for 8 hours. Such voids were not formed in the systems with low temperature. This paper described the investigation into the production of pure Al matrix composites, the eject of processing temperature will be investigated and the resulting will be fully characterised.