저널

Dynamic nano-indentation method was applied to characterize thin electroformed Ni-P layers. The Ni-P layers were produced in a sulphamic acid bath at $50^{circ}C$ in $0.02A/cm^2$ for 10-60 minutes. The chemical analyses by XRD and EDX showed that the Ni-P layers were very fine grains with mainly $Ni_3P$ with Ni. The surface roughness determined by atomic force microscopy increased with thickness, which was relative to the surface morphology. The nano-hardness and the stiffness of the thin Ni-P layers with thickness of 1.9, 6.2 and $7.5{mu}m$ were 5.52, 6.52 and 6.77 [GPa] and 56.7, 76.2 and 108.0 [${mu}N/nm$], respectively. The elastic modulus of the Ni-P layer increased with thickness such as 37.29, 54.50 and 78.76 [GPa], respectively. The surface roughness of the electroplated Ni-P layers with diverse thickness was 8.66, 18.56 and 35.22 [nm], respectively. The enhanced nano-mechanical properties were related to mainly residual stress of the Ni-P layers.

Ni-P deposit;Dynamic nano-indentation method;