Optimization of holding time on microwave irradiation of the composite iron-chromium reinforced with alumina particle

Abstract

In this study, the effect of holding time on the microwave sintered 84Fe-11Cr-5Al2O3 metal matrix composite (MMC) was investigated. Sintering was carried out in a tubular microwave furnace HAMiLab-V3 under N2 atmosphere. The holding time was selected between 0 to 75 minutes with increment of 15 minutes respectively. A study of microstructure and physical properties was carried out on sintered samples. It was discovered that, when the samples sintered at 1400oC with 20oC/min heating rate, the hardness was significantly increased from 110Hv to 160 Hv for holding time ranging from 30 to 45oC/min. Further increment until 75 minutes of holding time, no significant changes were obtained and hardness values were at steady state. The enhancement of bulk density and reduction of porosity were observed commences at 30 minutes until 45 minutes holding time. However, the results showed that the optimum holding time was at 45 minutes where the micro hardness is at the highest point which is about 160Hv.