Study of the phase transformations in Al-V2O5 composite fabricated by spark plasma sintering process

In this research, fabrication of an in-situ composite via spark plasma sintering method in an Al-V2O5 system was investigated. For this purpose, the powders of Al and V2O5 with three combination Al-41.94wt%V2O5, Al- 22.93wt%V2O5 and Al-15.78wt%V2O5 were mixed for 2 hours and then compressed and sintered at 550˚C by spark plasma sintering method. To study the temperatures of occurrence of phase changes was used from differential thermal analysis. spark plasma sintering samples with respect to peak reaction temperatures in differential thermal analysis were subjected to heat treatment for 10 minutes at a temperature range from 650 to 1050 ˚C and then cooled inside the furnace to ambient temperature. According to the X ray diffraction results, it was found that the phases of VO, α-Al2O3, Al3V, Al6V, Al11V were formed in the samples. Samples sintered at 650˚C have a highest density. With increasing temperature and percentage of aluminum in the initial powder mixture, the density of the samples decreased due to increase of porosity and cavity. Measured densities were in the range of 2.5 -3 g/cm3. The hardness of the samples was increased by an increase in temperature and decreased by an increase in the percentage of aluminum in the mixture of the initial powder. Hardness of the tested specimens was in the range of 52 to 123 HV.