Effect of parameters: Milling time and wt. % Al2O3 on mass density and hardness of Al2O3/Cu micro-composite

Abstract

The new technologies require materials with multi-functional properties that cannot be met by conventional materials. Alumina (Al2O3) and pure copper (Cu) can be combined to form a multi-functional material with mechanical, tribological, and thermo-electrical properties. In this study, ceramic material Al2O3 with 0 wt.%, 1 wt. %, 2 wt. %, 3 wt. %, 4 wt. %, and 5 wt. % were added into the pure Cu matrix using a powder metallurgy method at various milling times. Different weight ratios of Al2O3 and Cu powders were pressed using a hydraulic press machine and sintered in a muffle furnace. A scanning electron microscope (SEM) and energy dispersive X-ray (EDX) were used to examine the surface morphograph and chemical elements of the micro-composite, respectively. The presence of Al2O3 in the sample is revealed by surface morphograph. The SEM images of the Al2O3/Cu micro-composite at various milling times show that the agglomeration tendency of the Al2O3 particles, as well as the Al2O3 particle size, decreases with increasing milling time. The presence of chemical elements such as Cu, Al, and O in the micro-composite is indicated by EDX analysis. The addition of Al2O3 particles into pure Cu reduces the mass density of the micro-composite samples and increases slightly as the milling time increases. The hardness analysis reveals that as the wt. % of Al2O3 particles and milling duration increases, the hardness value of pure Cu increases. The hardness of an Al2O3/Cu micro-composite is strongly dependent on the wt. % of Al2O3 particles, the Al2O3 particle size, the existence of porosity, the milling duration, and the distribution of the Al2O3 particles in the micro-composite samples.