Structure and property of Ni-W-B alloy electrodeposits before and after heat treatment

Abstract

The structure and microhardness of Ni-W-B alloy were studied by means of electrochemical techniques, XPS, DSC and XRD before and after heat treatment. The results showed that the process of Ni-W-B alloy electrodeposition was accompanied by the chemical deposition of Ni and adulteration of Na2B4O7 in the deposit. Ni-W alloy presented in nanocrystalline structure and Ni-W-B in amorphous structure were both coarsened in grain size and led to the evolution of Ni4W, and precipitation of Ni - B compound such as Ni2B, Ni3B in Ni-W-B alloy after heat treatment, The maximum microhardness could be observed for Ni-W alloy at the value of 919.8 kg . mm(-2) after heat treatment for 2 hours at temperature of 400 degreesC and Ni-W-B alloy at 1132.2 kg . mm(-2) (500 degreesC, 2 hrs).