The heat treatment effect on microstructure and dynamic mechanical properties of electroformed nanocrystalline Ni–W alloy

Ni–W alloys coatings with minimum residual stress can be electrodeposited by using electrodepositing bath with additive saccharin at ∼2.5 g/L. Grain size of electroformed Ni–36.4 wt% W heat-treated at below 400 °C grew slowly with heat treatment temperature rising. However, it grew quickly as heat treatment temperature increased from 400 °C to 500 °C. The dynamic strength of electroformed Ni–36.4 wt% W alloy after heat treatment increases but the dynamic ductility decreases with strain rate increasing in the range of 2800–5400 s−1. At the strain rate 2800 s−1, the best dynamic strength and ductility of Ni–36.4 wt% W alloy can be obtained by heat treatment at 300 °C comparing with that as-deposited and heat treatment at 200–500 °C.