Effect of MGZN2 addition on the sintering density, microstructure and hardness of aluminum alloys prepared by powder metallurgy method

In this study, the aluminum alloys with different MgZn 2 contents were prepared using the powder metallurgy method.The effect of the MgZn 2 contents on the sintering density, porosity, microstructure and microhardness was investigated using optical microscopy, scanning electron microscopy (SEM), X-ray diffraction, and Vickers microhardness.The function mechanism of the intermetallic compounds formed as a result of MgZn 2 addition was analyzed.The results revealed that the highest sintering relative density (95.1%), lowest porosity volume fraction (4.81%), and highest hardness (112.4HV) were observed with the 5% addition of MgZn 2 contents.The XRD results show that the microstructure of the bare sample (Al) is mainly composed α-Al phase, while, with the addition of MgZn 2 , the microstructure turned to have α-Al phase and some intermetallic compounds of Al 5 Mg 11 Zn 4 and AlMg 4 Zn 11 .These intermetallic compounds were formed with higher density at the grain boundaries as white precipitates.