DETERMINATION OF THIN FILM'S MECHANICAL PROPERTIES

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c)
Figure 5.3 Borided layer thickness of 1020 steel for different process time SAE 1020 steel
a) 2 h borided, b) 4 h borided, c) 6 h borided
During boriding, the diffusion and subsequent absorption of boron atoms into
metallic lattice of component surface form interstitial boron compounds. The
resulting layer may consist of either a single phase boride or polyphase boride layer.
Saw-tooth shape diffusion microstructures of borided SAE 1020 and SAE 1040 are
illustrated in Figure 5.3. and Figure 5.4., respectively. From SEM-BEC photographs
can be seen that films consist of two different diffusion layers. According to the
micro structure graphs; dark region symbolizes FeB diffusion layer while bright
areas indicate Fe 2 B diffusion layer. Increase in time from 2h to 6 h, FeB and Fe 2 B
layers thicknesses increase; as expected.