24
M. V. Ved’ et al.
Fig. 1.18 (continued)
A series of diffraction lines for α-Co on X-ray diffraction patterns for Co-Mo-Zr
deposits on steel substrates was obtained (Fig. 1.19). No other phases including
intermetallic compounds were found in the coating structure even after a 3-h
annealing of the coated sample on the air at a temperature of 870 K. Furthermore,
one can find a small halo with full width at half maximum about 5 ◦ at angles
2θ ∼59 ◦ , which indicates an XRD amorphous structure of above materials [45].
Thus content of the alloying metals in the coating Co-Mo-Zr deposited from
polyligand citrate-pyrophosphate electrolyte depends on the current density and on/off-times extremely, and maximum Mo and Zr content corresponds to the current
density interval of 4–6 A/dm 2 and on-/off-time of 2–10 ms. It was established the
coating enrichment by molybdenum with current density increasing up to 8 A/dm 2
as well as the rising of on-time and off-time promotes the content of molybdenum
because of subsequent chemical reduction of its intermediate oxides by hydrogen
ad-atoms. Developed and globular surface of Co-Mo-Zr as well as composition of
material may be associated with high catalytic activity.
M. V. Ved’ et al.
Fig. 1.18 (continued)
A series of diffraction lines for α-Co on X-ray diffraction patterns for Co-Mo-Zr
deposits on steel substrates was obtained (Fig. 1.19). No other phases including
intermetallic compounds were found in the coating structure even after a 3-h
annealing of the coated sample on the air at a temperature of 870 K. Furthermore,
one can find a small halo with full width at half maximum about 5 ◦ at angles
2θ ∼59 ◦ , which indicates an XRD amorphous structure of above materials [45].
Thus content of the alloying metals in the coating Co-Mo-Zr deposited from
polyligand citrate-pyrophosphate electrolyte depends on the current density and on/off-times extremely, and maximum Mo and Zr content corresponds to the current
density interval of 4–6 A/dm 2 and on-/off-time of 2–10 ms. It was established the
coating enrichment by molybdenum with current density increasing up to 8 A/dm 2
as well as the rising of on-time and off-time promotes the content of molybdenum
because of subsequent chemical reduction of its intermediate oxides by hydrogen
ad-atoms. Developed and globular surface of Co-Mo-Zr as well as composition of
material may be associated with high catalytic activity.