54
A. V. Taran et al.
3 Results and Discussion
Figure 2a–d presents SEM surface morphology images of B 4 C coating on AISI 430
and AISI D3 steel, respectively. In Fig. 2 b, almost spherical nodules forming clusters
or so-called “cauliflower” structure indicating columnar growth of B 4 C coating was
revealed. The surface morphology of B 4 C on AISI D3 was free of droplet phase due
to RF sputtering technique.
X-ray energy-dispersive spectrometry (EDX) revealed that the coatings were
mostly corresponded to the stoichiometric composition of boron carbide B—75 at.%
and C—20 at.% with some amount of Fe and Cr from the substrate material.
The tribological tests of the coatings have been carried out. The wear tests showed
that the maximum weight loss was observed for boron carbide coating deposited
on AISI 430 steel (Table 2). The gain of the mating part was revealed in these
samples associated with the setting of the contacting counter-specimen material and
the destruction of the coating due to poor adhesion to the substrate. The cracks were
formed in B 4 C coating on 3.0-µm-thick AISI 430 substrate at a load of 0.098 N
(Fig. 2a). The cracks were spreading from the vertices of the pyramidal indenter tip.
When the load is increased to 0.49 N, the peeling of the coating was also observed
(Fig. 3b). So the surface was quite brittle due to the formation of blisters. According
Fig. 2 SEM surface images of B 4 C coating on AISI 430 (a, b) and AISI D3 (c, d) substrates
A. V. Taran et al.
3 Results and Discussion
Figure 2a–d presents SEM surface morphology images of B 4 C coating on AISI 430
and AISI D3 steel, respectively. In Fig. 2 b, almost spherical nodules forming clusters
or so-called “cauliflower” structure indicating columnar growth of B 4 C coating was
revealed. The surface morphology of B 4 C on AISI D3 was free of droplet phase due
to RF sputtering technique.
X-ray energy-dispersive spectrometry (EDX) revealed that the coatings were
mostly corresponded to the stoichiometric composition of boron carbide B—75 at.%
and C—20 at.% with some amount of Fe and Cr from the substrate material.
The tribological tests of the coatings have been carried out. The wear tests showed
that the maximum weight loss was observed for boron carbide coating deposited
on AISI 430 steel (Table 2). The gain of the mating part was revealed in these
samples associated with the setting of the contacting counter-specimen material and
the destruction of the coating due to poor adhesion to the substrate. The cracks were
formed in B 4 C coating on 3.0-µm-thick AISI 430 substrate at a load of 0.098 N
(Fig. 2a). The cracks were spreading from the vertices of the pyramidal indenter tip.
When the load is increased to 0.49 N, the peeling of the coating was also observed
(Fig. 3b). So the surface was quite brittle due to the formation of blisters. According
Fig. 2 SEM surface images of B 4 C coating on AISI 430 (a, b) and AISI D3 (c, d) substrates