Pulse co-electrodeposition of nano Al2O3 whiskers nickel composite coating

Electro co-deposition of Ni–Al2O3 composite coatings

“…8 clearly show that the hardness of the composites increased compared to that of pure nickel with the addition of Al 2 O 3 particles, in agreement with literature findings [e.g. 6,10,16,19,20,29]. The hardness values measured in this research are in the same range of the values reported by Chen et al [16] (320 HV for pure nickel and 470 HV for composites containing 8.5 vol.% of 0.8 lm Al 2 O 3 particles co-deposited from a Watt bath), and Srivastava et al [25] (370 HV for Ni-Al 2 O 3 composites containing 1 lm Al 2 O 3 particles deposited from a sulphamate bath).…”

“…Furthermore, the increased commercial availability of smaller particle sizes has increased the potential applications of these composite coatings [4]. For example, sub-micron powders promote the homogeneity of the composite through the increase of the contact area between metal and particle and also permit the application of composite materials in microdevices and thin films [5]: oxide particles such as Al 2 O 3 and TiO 2 [4] or fibres and whiskers [6] have been deposited with metals to produce composite coatings with a significantly higher yield strength and hardness than the pure metal; metallic films containing hard materials, like diamond, WC and SiC, protect the substrate from abrasion and sub-micron powders, like Al 2 O 3 , BaSO 4 , Si 3 N 4 , V 2 O 5 and Cr 2 O 3 can be incorporated to decrease the corrosion rate of the metal; graphite, MoS 2 and PTFE are electro co-deposited to produce composite coating that can be employed in moving contact devices because they reduce the friction between the surfaces [1,2].…”

“…Pure nickel films have been widely employed for their corrosion resistance [7,8], this property can be combined with the mechanical properties of alumina to produce Ni-Al 2 O 3 composite films exhibiting enhanced hardness [6, and wear resistance [9,13,16,22,25,26,[28][29][30][31] whilst maintaining the corrosion resistance of nickel [ [18], 321, [33,34]]. Whilst there is a considerable amount of literature available on this composite material a systematic investigation of the main deposition parameters has not been considered in detail.…”

Pulse electrodeposition of Ni/nano-TiO2 composites: effect of pulse frequency on deposits properties

“…1). Under specific electrolysis conditions (pH, J) an analogous increment of codeposition percentage with increasing pulse frequency has been observed for Ni/ Al 2 O 3 composite coatings [22,31], although contradictory conclusions also exist in literature [21,32]. Therefore, to elucidate the correlation between pulse frequency and codeposition percentage, this study covers an extended range of pulse frequencies and electrodeposition parameters.…”

“…Pulse plating has yielded many nickel matrix composites, such as Ni-SiC [19,20], NiAl 2 O 3 [21,22], Ni-ZrO 2 [23], Ni-WC [24] and Ni-diamond [25]. It is worth to be mentioned that relatively less research study has been done in the field of quantitative texture analysis of composite nickel electrodeposits under various PC conditions [11,19,24,26].…”