Microstructural Evolution and Physical Properties Changes during Liquid Phase Sintering of Fe-Cu-C Compacts

Deeper understanding on the powder metallurgy method and the sintering process have granted in advanced development in the powder metallurgy industries. Fe-Cu-C is the leading materials in powder metallurgy method because of its ability for liquid phase sintering theoretically above melting point of copper; 1083 ˚C, thus strengthening the structure. The sintering temperature is important as it affect the diffusion of copper and carbon into iron matrix. Therefore the objective of this project was to study the microstructural evolution and the mechanical properties under different sintering temperature of mixed iron, copper, and carbon (Fe-Cu-C) compacts during liquid phase sintering. The effect of compaction pressure to the densification of Fe-Cu-C powder was also discussed in this study. Raw materials of pure iron, copper and carbon powder were mixed to the standard of Metal Powder Industry Federation (MPIF) of FX2008 (79 wt.% Fe, 20 wt.% Cu, and 1 wt.% C). The Fe-Cu-C powders were compacted into a pellets using hand press machine at different compaction pressures from 180 MPa to 600 MPa and sintered in a 5% H2 + 95% N2 gas atmosphere at different sintering temperature in the range of 1000ºC to 1200ºC. This study showed that the optimum sintering temperature that result in highest density of 6.76 g/cm3 and highest hardness value of 200 HV was at 1200 ˚C. The compact pressure was at 600 MPa to minimise the porosity of the sample