DETERMINATION OF THIN FILM'S MECHANICAL PROPERTIES

39
140
120
SAE 1040 Quality Steel Borided at 900 C
2h borided
4h borided
6h borided
100
Intensity (%)
80
60
40
20
0
39 44 49 54 59 64 69
2 Theta
Figure 5.2 Phase analysis of 1040 steel borided at 900 o C for 2h, 4h and 6h.
Both XRD examinations of borided layers show that only FeB phase exists on the
surface. But if used SEM, cross-sectional investigation of layers demonstrate that
two diffusion layers (FeB and Fe 2 B) in saw-tooth shapes.
5.1.2 SEM and Thickness examination
SEM cross-sectional investigations show that double phase layer from surface to
inside of substrate. SEM cross-sectional photograph of SAE 1020 and SAE 1040
quality steels, which was borided at 900 o C for 2, 4 and 6h, are shown in Figure 5.3.
and Figure 5.4., respectively. The structural compositions of layers consist of boron
rich phase (FeB) and iron rich phase (Fe 2 B), respectively. FeB formation begins from
surface, Fe 2 B phase forms in deeper region because of decreasing boron
concentration form surface to inside of substrate. According to the SEM photograph,
saw tooth microstructural images show both FeB and Fe 2 B phase.