Densification, Microstructure and Mechanical Properties of Al-4.5 wt.% Cu Alloy Powder Sintered Through Spark Plasma Sintering Process

The effect of sintering pressure on densification, microstructure and mechanical properties of SPS compact of Al-4.5 wt.% Cu alloy powder was investigated. The size of the powder varied from 1 to 600 µm was subjected to SPS at constant temperature of 450 °C for different pressures. The powder sintered at 40 and 50 MPa pressure is highly dense compact exhibited the microstructure of different grains sizes with the uniform distribution of the secondary phase particles. The sintering mechanism such as particle rearrangement, localized and bulk deformation revealed from the microscopy and data received from the SPS equipment are found to be involved during the sintering process. The highest compression strength of 360 MPa is achieved at compact pressure of 40 MPa due to fine microstructural distribution of secondary phase. The compact produced at 50 MPa exhibited highest hardness of 838 MPa since the strong metallurgical bonding between the powder particles.