Abstract
A molten magnesium bath was used to siliconize iron and steel specimens embedded in SiC powder for various periods at 973-1123K. The siliconized layer obtained was composed of Fe3Si phase as the matrix and SiC phase as dispersed particles.
Therefore, a hard composite layer, as high as 820 of Vickers hardness number, could be obtained.
The thickness of the layer varied depending on the siliconizing temperature and time. Then the thickness was measured as to iron specimens siliconized with 5μm-SiC powder and then the diffusion coefficient was calculated as,
D=34.22×10-4exp[-186.30(kJ/mol)/RT] (m2/s). The thickness of the layer could also vary with SiC powder size of 2 to 40μm, the smaller in the size, the thicker in the layer. However, SiC powder of 5μm was thought to be suitable practically.
