Microstructure and properties of pure aluminum prepared by spark plasma sintering

Abstract

Pure Aluminum (Al) powder was densified by spark plasma sintering (SPS). The effects of sintering temperature (450–600 °C) on microstructure, density, hardness and corrosion resistance of the sintered samples were investigated. The methods used in the present study were scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, X-ray diffraction, electrochemical workstation and hardness measurements. The results show that the sintering temperature obviously affects the hardness, relative density, microstructures and corrosion resistance of the sintered Al samples. However, there are different trends with increasing sintering temperature. The maximum hardness (37.7 HV) was obtained at the sample sintered at 550 °C. The polarization curves and corrosion morphology analyses indicated that the sample sintered at 450 °C has the best corrosion resistance (Icorr = 0.344 µA · cm−2). Besides, it was found that the sample sintered at 600 °C was burnt and had many holes along grain boundaries and at triple junctions.