Effect of interface behavior between particles on properties of pure Al powder compacts by spark plasma sintering

Pure Al powder was sintered by spark plasma sintering (SPS) process at various sintering temperatures and loading pressures. The density, electrical resistivity, tensile properties and microstructure of powder compacts were investigated, The powder compacts with the similar properties as base aluminum metal was obtained at sintering temperature above 873 K, loading pressure above 23.5 MPa. For the powder compacts with the similar density but with the large difference in the electrical resistivity and tensile properties, the interfaces between Al powder particles were investigated using high resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (EDS). Two types of interfaces, with metal/metal bonding and metal/oxide film layer/metal bonding, were observed in Al powder compacts. The properties of powder compacts were mainly subject to the behavior of oxide film between the powder particles.