Elemental mapping analysis
Elemental mapping analysis was performed to verify the distribution
of carbon atoms. The substrate's surface area and the results are
displayed in Fig. 6. The white dots symbolize the existence of carbon
atoms. It is clearly observed that the concentration of carbon atoms is
highly packed and uniform in the PC sample and that the atoms are
diffused further into substrate compared to the conventional carburizing
samples. The results confirm to the hardness gradient of the
sample's cross-sections as shown in Fig. 7. As expected, the PC sample
exhibits the highest surface hardness. Meanwhile, the hardness
decreases towards the core which indicates a reduction in the concentration
of carbon.