The Elevated Temperature Tensile Properties of Electrodeposited Nickel

Abstract

Elevated temperature tensile testing of Watts nickel produced at a current density of 537 A/m² has shown that embrittlement occurs at temperatures above 400°C. The cause of the embrittlement has been attributed to the formation of gas filled bubbles; the gas being carbon monoxide. It is suggested that in these deposits with large even grain sizes both plastic strain and thermal energy are required to form vacancy “clusters” which might effectively act as bubble nucleation sites. The fissuring of gas bubbles and the consequent gas release at the surface of the specimens during tensile straining encourages crack propagation via grain boundaries. The extent of surface fissuring is shown to be dependent on temperature and strain rate.