Microstructural and mechanical properties of AI-AI_2O_3 composites focus on experimental techniques

摘要

In the present study, Al-Al_2O_3 composites were prepared. Since temperature and time in casting process are two important parameters, in this investigation a method was used to reduce the harmful effects these factors. In addition, in order to study the wettability and distribution of the reinforcement particle, Al_2O_3 particles were injected into the melt in four different forms, i.e., untreated Al_2O_3 particles, heat-treated Al_2O_3 particles, milled particulate Cu-Al_2O_3 and Al-Al_2O_3 composite powder. Microstructural features of the matrix and distribution of Al_2O_3 particles within it, were evaluated by scanning electron microscopy and optical microscopy. In addition, the variations of hardness, impact energy, yield strength and wear resistance were measured. Results revealed that the maximum values of hardness, yield strength and impact energy are observed for Al_2O_3-Al reinforced sample with values of 78.7 BHN, 142 MPa and 8.2 J, respectively.