Pengaruh Fraksi Penguat Fly Ash dan Temperatur Cetakan terhadap Sifat Kekerasan dan Struktur Mikro pada MMC

Metal Matrix Composite is a metal composite that utilizes an aluminum alloy as a matrix in its fabrication and has a wide application in industry. Fly ash is a coal-burning waste at the steam power plant that contains a high enough reinforcement fraction in the form of alumina (Al2O3) and silica (Si). Process of making specimens using an amplifier the powder metallurgy method. Fly ash as reinforcement was varied in powder mixing by 5%, 10%, 15%, 20%, and 25%. The compaction process is carried out with hot isostatic pressure so that the powder becomes softer and makes it easier to compact. Effect of heating temperature on the mold varied at 250oC, 300oC, and 350oC to obtain a homogeneous bond. In the research conducted, the results showed that the hardness value of the specimen increased by 1.7% by 65.07 HRB at 10% fly ash reinforcement variation, then continuously decreased to 16.92% with a hardness value of 55.64 HRB in the reinforcement variation. Fly ash 25%. The results of scanning electron microscope observations show that the influence of the heating temperature of the mold provides an even distribution of particles at a temperature of 300oC. bonded particles between the matrix and reinforcement are better and at temperatures of 250oC and 350oC shows an uneven distribution of reinforcing particles and results in agglomeration of reinforcing particles in the specimens are The resulting product is brittle and causes a decrease in hardness in the variation of the fraction with fly ash content above 10%.