چكيده به لاتين
Aluminum is very remarkable due to its unique properties in the field of composite fabrication, especially in MMC,s.
In this research, a functional graded composite with Aluminum matrix is fabricated. The method used for this composite is powder method. The purpose of this study is to investigate effect of various parameters such as sintering temperature, sintering time, reinforcement particle content and atmosphere on the properties of Aluminum composites with Al2O3, SiO2 and TiO2 reinforcement particles.The size of the Aluminum particles is about 30 μm with a purity of 99.5%, Al2O3 with an average particle size of 10 μm, SiO2 with a average particle size of 100 μm, and TiO2 with an average particle size of 30 μm.
After mixing Aluminum powder with 5, 10, and 15 weight percent of reinforcement, the powder was compressed using a single axis press.for sintering of composite temperature of 550 ° C and 650 ° C and 2 hours in resistive furnace was used. Also , to investigate the effect of sinter time on composite properties 7 hours at 550 ° C was used. To study the effect of the atmosphere at 550 ° C for 2 hours, an argon gas protective tube furnace was used.Al-Al2O3-SiO2, Al-Al2O3-TiO2 and Al-SiO2-TiO2 composites were fabricated to determine the effect of reinforcements alongside in Aluminum matrix, and placed in a resistance furnace at 550 ° C for 2 hours.
Also, to study the distribution of reinforcement in the matrix and the fracture surface of the specimen, SEM images, the distribution of elements in the sample the X-ray map and for field analysis EDS were used.
It was concluded that with increasing weight percent of reinforcement from 5 to 15 percent, the composite hardness increases respectively from 31 to 38 ، 26 to 38 and 22 to 32. By changing the sintering temperature from 550 to 650 ° C, the hardness decreased, and the grain
of the matrix became coarser and the density increased.for example hardness of composite with 10 weight percent of Alumina decreased from 36 to 27 vickers by increasing temperature from 550 ° C to 650 ° C. By changing the atmosphere to argon gas, the hardness increased, and the granulation and microstructure became more homogeneous.hardness of composite with reinforcement particles of Al2O3 from 36 to 44 ، SiO2 from 36 to 38 and TiO2 from 28 to 35.
