THE EFFECT OF Pb ON MICROSTRUCTURE, MECHANICAL PROPERTES AND MACHINABILITY OF IN-SITU Al-15%Mg2Si COMPOSITE

Mechanical and physical properties of light metal matrix composite (MMC) indicate that these materials play an important role in engineering applications. In this research, the effect of Pb on the microstructure and machinability of Al-15%Mg2Si composite were investigated. Machining test was carried out on different composition of Pb added composites (varying from 0.1 to 5%wt. Pb). Characterization of the composite specimens was carried out by optical and scanning electron microscopy (SEM). The result show- In constant machining parameters, e.g. cutting speed, feed and depth of cut, Pbaddition in lower contents has no influence on the machinability of the composite. But, at higher content (> 1 wt. %Pb), the machinability has been improved. The microstructural examination showed that addition of Pb change the morphology of primary and secondary Mg2Si particle. It was also found that theaddition of 1%Pb reduces the average size of primary Mg2Si from 45 μm to 13 μm. As the mount of Pbincreased up to 1 wt.%, ultimate tensile strength (UTS) and elongation values were also increased from 167 MPa and 2.7% to 195 MPa and 4.3%, respectively

Keywords:

Metal matrix composite (MMC) , Mg2Si particles , Machinability