Microstructural and Mechanical Characterization of Spark-Plasma-Sintered Compact of Al-4.5 wt.% Cu Alloy Powder

Abstract

Al-4.5 wt.% Cu alloy powder was produced by inert gas spray atomization process. The size of the powder in the range of 10 to 500 µm produced by spray atomization process was analyzed using laser particle analyzer. The smaller powder particles of size less than 25 µm are of spherical shape, whereas larger-sized powders are elongated and irregular-shaped. The smaller powder particles exhibit cellular morphology and are of equiaxed grains. The longer and irregular-shaped powder reveals coarse grains, whereas elongated grains exhibit dendritic morphology. The powder of different sizes was compacted by spark plasma sintering by applying temperature and pressure simultaneously. The density of the compact was determined using water displacement method, and the average density of the compact was 2.65 g/cc. After compacting and sintering the powder, 95 percent relative density of the compact is achieved. The porosity present in the compact was captured by optical metallurgical microscope. The microstructural characterization of powder and sintered compact was carried out by using optical metallurgical microscope and scanning electron microscope. The micro-hardness of the compact was tested using micro-Vickers hardness testing machine, and the hardness was found to be varied from 67.1 to 69.6 HV. The yield strength, ultimate strength and ductility of the sintered compact were determined by conducting the compression test.